 Subjects -> ANIMAL WELFARE (Total: 103 journals)
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- An analysis of the influence of preslaughter management factors on welfare
and meat quality outcomes in fed beef cattle in the United States
First page: txae108
Abstract: AbstractDuring the preslaughter phase, cattle are transported from their place of origin to a slaughter facility, experiencing transportation, lairage, environmental factors, and novel environments. Although research exists that has focused how the preslaughter phase impacts cattle welfare and meat quality, some significant preslaughter management factors and subsequent welfare and meat quality outcomes have not been thoroughly explored. The objective of this study was to assess the effects of preslaughter management factors on welfare and meat quality outcomes in fed beef cattle in the United States. Transportation factors, environmental characteristics, lairage factors, cattle characteristics, and several meat quality variables were collected from 5 federally inspected commercial processing facilities in the United States. After excluding slaughter lots that included <75% complete datasets, a total of 619 slaughter lots representing 84,508 head of cattle were used for further analysis. Predictor variables of interest included processing plant, cattle breed, sex class, operation shift at the plant, distance traveled to the plant, truck waiting time to unload at the plant, lairage duration and space allowance, temperature humidity index, and windspeed. Outcome variables of interest included cattle mobility, carcass bruising, dark cutting (DC), quality grades, and hot carcass weights. Logistic and linear regressions were used to analyze the associations between the predictor and outcome variables of interest. Increased distance traveled and truck waiting time were associated with higher odds of mobility impairment (P = 0.0009 and P = 0.007, respectively), with each 10 km increase in distance traveled having an odds ratio (OR) of 1.001 (95% confidence interval [CI]: 1.000 to 1.001) and each 1-min increase in waiting time having an OR of 1.003 (CI: 1.001 to 1.004). Conversely, a 10-km increase in distance traveled decreased the odds of carcass bruising (OR: 0.997, CI: 0.996 to 0.998; P < 0.0001). Longer lairage was associated with increased odds of DC (P = 0.0415), with each 60-min increase in duration having an OR of 1.034 (CI: 1.001 to 1.068). The results demonstrate the importance of truck arrival management (i.e., scheduling, prioritizing unloading) on mobility. Focusing on lairage management (i.e., density and time) may provide some opportunities to improve meat quality.
PubDate: Mon, 22 Jul 2024 00:00:00 GMT
DOI: 10.1093/tas/txae108
Issue No: Vol. 8 (2024)
- Effect of forage quality and narasin inclusion on ruminal fermentation,
nutrient intake, and total tract digestibility of Nellore steers
First page: txae107
Abstract: ABSTRACTThe study aimed to evaluate the effects of forage quality and narasin inclusion on intake, digestibility, and ruminal fermentation of Nellore steers. Twenty-eight rumen-cannulated Nellore steers (initial body weight [BW] = 350 ± 32.4 kg) were allocated to individual pens in a randomized complete block design, with 7 blocks, defined according to the fasting BW at the beginning of the experiment. The steers were randomly assigned within blocks to 1 of 4 experimental diets in 2 × 2 factorial arrangements, being the first-factor forage quality (MEDIUM = 81 g of CP/kg of dry matter [DM], and HIGH = 153 g of CP/kg of DM), and the second factor was the inclusion (N13 = diet plus 13 mg/kg of DM of narasin) or not (N0) of narasin (Zimprova; Elanco Animal Health, São Paulo, Brazil). The experiment consisted of a 28-d period with 22 d for adaptation and the last 6 d for data collection. No haylage quality × narasin interaction (P ≥ 0.68) was observed on DM and nutrient intake. Haylage quality affected (P ≤ 0.01) DM intake, with greater values observed for steers fed HIGH compared with MEDIUM haylage. There was an increase (P < 0.001) in OM, NDF, hemicellulose, and CP intake for steers consuming HIGH vs. MEDIUM haylage. Including N13 did not affect (P > 0.39) DM and nutrient intake of steers. No haylage quality × narasin interactions were detected (P ≥ 0.60) for total tract nutrient digestibility. However, steers fed with HIGH haylage showed an increase (P > 0.001) in DM and digestibility of all nutrients compared with MEDIUM. Steers fed a MEDIUM haylage had a greater (P < 0.01) proportion of acetate compared with steers fed HIGH during all evaluated hours. Steers fed HIGH haylage had a greater (P < 0.01) proportion of propionate at 0 h compared with steers consuming MEDIUM, whereas at 12 h, steers consuming MEDIUM hay had a greater (P < 0.01) proportion of propionate vs. HIGH haylage. A haylage quality × narasin and haylage quality × time of collection interactions were detected (P ≤ 0.03) for rumen ammonia concentration, which was reduced (P < 0.03) in N13 vs. N0 steers consuming HIGH haylage. Collectively, high-quality haylage allows increased consumption and digestibility, with more energy-efficient ruminal fermentation. In addition, narasin might be an important nutritional tool in forage-based diets to enhance the ruminal fermentation parameters of Bos indicus Nellore steers.
PubDate: Tue, 16 Jul 2024 00:00:00 GMT
DOI: 10.1093/tas/txae107
Issue No: Vol. 8 (2024)
- Determination of relative bioavailability of copper from copper glycinate
in growing beef steers
First page: txae105
Abstract: ABSTRACTChelated copper (Cu) sources, such as Cu glycinate (CuGly), may be more bioavailable relative to Cu sulfate (CuSO4) when fed to ruminants under antagonistic pressure. The objective of this study was to determine the bioavailability of CuGly (GemStone Cu; Phibro Animal Health) relative to CuSO4 in steers fed a diet supplemented with 0.3% sulfur and 2 mg molybdenum/kg of dry matter (DM). Sixty Angus crossbred steers (n = 12 per treatment) averaging 288 ± 4.85 kg were enrolled in a 90-d study and fed a corn silage-based diet with one of five Cu supplementation strategies, including no supplemental Cu (CON), 5 or 10 mg supplemental Cu from CuSO4/kg DM, and 5 or 10 mg supplemental Cu from CuGly/kg DM. Steers were housed in pens equipped with GrowSafe feed bunks (GrowSafe Systems Ltd., Airdire, AB, Canada), with six steers per pen. Growth performance, liver Cu, and plasma Cu were analyzed in the MIXED procedure of SAS 9.4 (SAS Inst. Inc, Cary, NC) with orthogonal contrasts to compare CON vs. 5 mg Cu/kg DM, CON vs. 10 mg Cu/kg DM, 5 vs. 10 mg Cu/kg DM, and CuSO4 vs. CuGly. Copper indices were regressed against Cu intake and slopes were calculated using the GLM procedure SAS. Dietary Cu supplementation did not affect steer body weights on days 0, 28, 56, or 90 (P ≥ 0.52), average daily gain, dry matter intake, or gain:feed (P ≥ 0.36). Final plasma Cu concentration did not differ between CON vs. 5 mg Cu/kg DM (P = 0.79), CON vs. 10 mg Cu/kg DM (P = 0.65), or 5 vs. 10 mg Cu/kg DM (P = 0.39). Steers receiving CuSO4 tended to have greater final plasma Cu concentrations than those receiving CuGly (P = 0.08). Initial liver Cu concentration averaged 374 mg Cu/kg DM, which is considered highly adequate. No steers reached deficient Cu status by the end of the 90-d period. Control steers had lesser final liver Cu concentrations than supplemented steers (P ≤ 0.04). Steers receiving 10 mg supplemental Cu/kg DM had greater liver Cu concentrations than those receiving 5 mg supplemental Cu/kg DM (P = 0.01). Copper source had no effect on final liver Cu concentrations (P = 0.57) and based on liver Cu and Cu intake the bioavailability of CuGly was similar to CuSO4 (115%; P = 0.27). The initially high Cu status and the fact that cattle did not become Cu deficient may have impacted the relative bioavailability results, and more research is needed to investigate the role initial Cu status and antagonistic pressure play in the bioavailability of chelated Cu sources.
PubDate: Fri, 12 Jul 2024 00:00:00 GMT
DOI: 10.1093/tas/txae105
Issue No: Vol. 8 (2024)
- A diverse diet increases animal growth performance and carcass yield of
grazing lambs
First page: txae103
Abstract: ABSTRACTThe current experiments were conducted across two lamb finishing seasons (2019 [experiment 1; Exp1] and 2020 [experiment 2; Exp2]). In both experiments lambs were provided a monotonous (MON) diet (annual ryegrass [Lolium multiflorum L.] during 2019 and perennial ryegrass [L. perenne L.] and white clover [Trifolium repens L.] during 2020) or a diverse (DIV) diet composed of spatially separated strips sown to chicory (Chicorium intybus L.), plantain (Plantago lanceolata L.), perennial ryegrass, lucerne (Medicago sativa L.), and dock (Rumex obtusifolius). During Exp1, the DIV lambs had a stocking rate (SR) of either 80, 95, 100, or 110 m2/lamb/wk, whereas the MON lambs had a 100 m2/lamb/wk SR. In Exp2, the SR aimed to allocate the MON lambs with twice the forage allowance (kg DM/lamb/d) as DIV lambs. In Exp1, all lambs provided DIV had a greater (P < 0.01) average daily gain (ADG; + 130%) than MON rams, independent of the SR. Accordingly, DIV had greater (P < 0.05) hot carcass weight (HCW; + 26%) and aged carcass weight (CW; + 27%) compared with MON, across all SR. The 80 m2/lamb/wk SR tended to have a greater (P = 0.10) dressing percentage and had similar (P = 0.29) drip loss percentage to the MON lambs, while the other DIV lamb SR all had greater (P < 0.05; +12%) dressing percentages and lower (P < 0.05) drip loss percentage than MON lambs. In Exp2, DIV lambs had greater (P < 0.01) ADG (+37%), HCW (+15%), and dressing percentage (+6%) compared with MON lambs. This improved animal performance occurred despite being offered 57% less (P = 0.01) dry matter (DM), 56% less (P < 0.01) digestible DM, and 57% less (P = 0.02) metabolizable energy per lamb per day. Ultimately, these experiments demonstrate that providing growing lambs a functionally diverse diet improves animal growth performance and carcass weight compared with a monotonous diet of annual ryegrass or a mixed sward containing perennial ryegrass with white clover.
PubDate: Wed, 10 Jul 2024 00:00:00 GMT
DOI: 10.1093/tas/txae103
Issue No: Vol. 8 (2024)
- Impact of increasing dietary standardized ileal digestible arginine to
lysine ratio from 0.85 to 1.15 and water-based arginine supplementation on
growth performance and gut integrity of weaned pigs
First page: txae102
Abstract: AbstractThe objective of this experiment was to assess the influence of arginine (Arg) supplementation in water and/or feed on the growth performance and gastrointestinal health of newly weaned pigs. Two hundred and forty pigs (5.06 kg; PIC, Hendersonville, TN) were randomly allocated into 80 mixed-sex pens (3 pigs/pen) and subjected to a 2 × 4 factorial design. Two levels of Arg were supplemented in water (0% or 8% stock, dosed through a 1:128 proportioner) for the first phase (days 0 to 7), and four dietary arginine levels (0.85, 0.95, 1.05, and 1.15) standardized ileal digestible (SID) Arg to Lysine (Lys) ratios for the first two phases (days 0 to 7 and 7 to 21). All treatments were provided a common diet (0.96 SID Arg:Lys) for the last phase days 21 to 42. One pig per pen underwent a dual sugar absorption test of lactulose at 500 mg/kg and mannitol at 50 mg/kg of body weight (BW) via gastric tube on days 7 and 21 postweaning, with blood plasma collected 4 h later. The pig tested on day 7 was subsequently euthanized for intestinal tissue collection. Pen growth performance and feed disappearance were evaluated for 3 phases: days 0 to 7, 7 to 21, and 21 to 42 postweaning. The statistical analysis used linear models to examine the effects of SID Arg:Lys in the feed, Arg level in water, and their interactions, with pen as the experimental unit. Orthogonal contrasts were used to test the linear and quadratic effects of increasing SID Arg:Lys in the diet. Growth performance during the first period exhibited variability, reflected by negative gain-to-feed (G:F) ratios, caused by the enteric health challenge. Consequently, data were analyzed separately for each phase. Increasing dietary SID Arg:Lys caused a linear improvement (P = 0.04) in final BW (18.47 and 21.90 kg, for 0.85 and 1.15 SID Arg:Lys, respectively). A trend (P = 0.09) suggested a linear impact of dietary SID Arg:Lys on average daily gain during days 21 to 42. Arg supplementation, whether administered through water or diet, did not affect lactulose and mannitol absorption on both days 7 and 21, nor did it alter histological measurements in the collected ileum tissues on day 7 postweaning. In conclusion, increasing dietary SID Arg:Lys increased final BW but had no clear impacts on intestinal health within the parameters measured, potentially impacted by the rotavirus diagnosis in the first week post-wean.
PubDate: Wed, 10 Jul 2024 00:00:00 GMT
DOI: 10.1093/tas/txae102
Issue No: Vol. 8 (2024)
- Effect of corn silage inclusion with different corn processing on
finishing steer performance and carcass characteristics
First page: txae101
Abstract: AbstractObjectives were to determine the effect of corn silage inclusion within dry-rolled corn (DRC) or steam-flaked corn (SFC) finishing diets on cattle growth performance and carcass characteristics. The experiment used British and continental crossbred steers (n = 480; initial body weight [BW] = 389 ± 17 kg) in a 4 × 2 factorial arrangement of treatments with six replications per treatment. Treatments consist of four inclusions of corn silage (0%, 15%, 30%, or 45%; dry matter [DM] basis) within either a DRC or SFC diet. A corn silage by corn processing interaction was observed for dry-matter intake (DMI; P = 0.05). As corn silage inclusion increased in the diet, DMI increased linearly (P < 0.01) for both corn processing methods. DM intake was not different between SFC and DRC-fed cattle at 0% (P = 0.33), 30% (P = 0.90), or 45% (P = 0.31) corn silage inclusion. The interaction was due to the DMI of cattle fed 15% silage, as cattle-fed DRC consumed 0.5 kg/d less (P < 0.01) than cattle on the SFC diet. Quadratic effects were observed for final BW, hot carcass weight (HCW), average daily gain (ADG), feed efficiency (G:F), marbling, and fat depth (P < 0.01), regardless of corn processing. Cattle fed 15% or 30% corn silage gained faster (P < 0.01) than those fed 0% or 45% corn silage. Feed efficiency decreased quadratically (P < 0.01) as silage inclusion increased in the diet with G:F similar for cattle fed 0% and 15% silage and decreased curvilinearly for cattle fed 30% and 45% silage. The incidence of liver abscesses was greater (P = 0.03) in cattle fed 0% corn silage than for steers fed 15%, 30%, or 45% corn silage. Corn processing method, independent of silage, had no effect (P = 0.42) on liver abscess incidence. Feeding SFC increased (P < 0.01) steer final BW and HCW when compared to cattle-fed DRC, regardless of silage inclusion. Corn silage inclusion had similar effects on performance in both DRC diets and SFC diets except for DMI. As corn silage inclusion increased in the diet, feed efficiency decreased linearly (P < 0.01). Cattle-fed SFC gained 7.9% more (P < 0.01) and were 6.7% more efficient (P < 0.01) than cattle-fed DRC. In diets containing either DRC or SFC, corn silage can be included at up to 30% of the diet without negative impacts on ADG or HCW.
PubDate: Wed, 03 Jul 2024 00:00:00 GMT
DOI: 10.1093/tas/txae101
Issue No: Vol. 8 (2024)
- Investigation of the diversity, equity, inclusion, and belonging within
the undergraduate student population within the Department of Animal
Science at Iowa State University
First page: txae100
Abstract: AbstractIowa State University (ISU) provides resources for diversity, equity, inclusion, and belonging (DEI-B) to provide students with a comfortable academic home regardless of their demographics or prior experiences. The objective of this study was to investigate undergraduate students’ DEI-B perspectives in the Department of Animal Science at ISU. One survey instrument was developed containing 14 questions that covered demographics, feelings of inclusion, comfort-seeking tools, and ways to improve DEI-B. Answer choices were either multiple choice, 1 to 5 sliding scale, or a specified text sliding scale. Eligible participants were undergraduate students enrolled in Animal or Dairy Science (n = 974). Demographics and comfort-seeking tools will be presented descriptively. Inclusion at the start and after 2 yr were compared using six different linear models. A variable was deemed significant if the P-value was ≤ 0.05. A total of 383 students (88% of total respondents) completed 50% or more of the inclusion questions. Seniors had the highest response rate. More students reported coming from a rural background. Primary species of interest was companion animals. There were no observed differences in feelings of inclusion in classes, with peers, or with faculty for hometown, admission type, ethnic group, and first generation when students started (P ≥ 0.067). There was a difference for primary species of interest (P ≤ 0.011) and with female students feeling less included (P ≤ 0.039). There were no observed differences after 2 yr in classes, with peers, or with faculty for classification year, admission type, or first generation (P ≥ 0.088). Suburban students felt the least included in classes compared to rural and urban students (P ≤ 0.036). Female students felt less included in all three categories (P ≤ 0.017). The majority of students reported having companion animal experience but almost half reported having no experience with livestock prior to ISU. A total of 51% of students said they never considered transferring to another major and 48% indicated that they plan to pursue a career in veterinary medicine. A total of 75% of students felt inclusion could be improved by creating more hands-on opportunities and 60% suggested the department provide more study space. In conclusion, the Department of Animal Science at ISU has some effective inclusion practices but needs to evolve and improve in its DEI-B practices for the undergraduate student population.
PubDate: Wed, 26 Jun 2024 00:00:00 GMT
DOI: 10.1093/tas/txae100
Issue No: Vol. 8 (2024)
- Blending gestation and lactation diets during the transition period
reduces energy mobilization by sows in late gestation, with no impact on
subsequent lactation performance
First page: txae096
Abstract: AbstractFifty-three gilts and fifty-three multiparous (MP) sows were used to evaluate a blended feeding program using gestation and lactation diets during the transition period on changes in sow back fat (BF) depth and BW, blood metabolites, and litter growth performance in the subsequent lactation period. A 2 × 2 factorial experimental design was generated including the factors of parity and feeding program. The MP sows and gilts were assigned to one of two feeding programs on day 104 ± 1 of gestation: 1) 2 kg/d of a standard lactation diet until farrowing when sows received step-up access to the lactation diet until ad libitum access was given on day 4 of lactation (CON) and 2) a dynamic blend of standard gestation and lactation diets that met estimated daily requirements for standardized ileal digestible Lys and net energy according to the NRC (2012) until day 4 of lactation where sows were provided ad libitum access to the lactation diet (TRAN). Litters were standardized to 13 ± 1 piglets within 24-h of birth. In gestation, ADFI was greatest for TRAN-MP sows (interaction; P < 0.05), with greater ADFI for TRAN versus CON sows (main effect; 2.95 vs. 2.13 ± 0.08 kg; P < 0.05). Feeding program did not influence ADFI in lactation, but MP sows had greater ADFI versus gilts (main effect; 5.96 vs. 4.47 ± 0.28 kg; P < 0.001). Immediately after farrowing, TRAN sows had greater BW and BF vs. CON sows, regardless of parity (main effect; 224.1 vs. 215.4 ± 4.1 kg and 17.3 vs. 16.2 ± 0.4 mm, respectively; P < 0.05). At weaning, no feeding program-related differences were observed for BW or BF, but MP sows had thicker BF compared to gilts (main effect; 14.4 vs. 13.4 ± 0.5 mm; P < 0.05). The TRAN-MP sows had heavier piglets at birth compared to all other groups (interaction; P < 0.05) and MP sows had greater litter birth weight and average piglet BW at birth versus gilts (main effect; P < 0.05). No effect of feeding program was observed for piglet BW at weaning. On lactation day 1, serum beta-hydroxybutyric acid and non-esterified fatty acid concentrations were lower for TRAN compared to CON sows (main effect; 12.0 vs. 19.4 ± 7.8 mmol/L and 0.35 vs. 0.57 ± 0.10 mmol/L, respectively; P < 0.05) and serum glucose concentration was greater for TRAN compared to CON sows (main effect; 4.41 vs. 3.88 ± 0.22 mmol/L; P < 0.05), but these differences were no longer detectable at weaning. Therefore, a simple transition feeding program using a blend of a standard gestation and lactation diets reduced energy mobilization by sows in late gestation, with no impact on subsequent lactation performance.
PubDate: Wed, 19 Jun 2024 00:00:00 GMT
DOI: 10.1093/tas/txae096
Issue No: Vol. 8 (2024)
- Supplementation with live Saccharomyces cerevisiae boulardii during the
initial 42 days of the feedlot phase in Nellore beef cattle
First page: txae097
Abstract: AbstractThis study aimed to assess the effect of Saccharomyces cerevisiae boulardii CNCM I-1079 supplementation during the initial feeding period on the performance of Nellore bulls in a feedlot system. One hundred ninety-eight Nellore bulls were used in a completely randomized block design, with blocking based on weight within each treatment group: light (331.4 kg; 4 pens), medium (349.7 kg; 4 pens), and heavy (362.5 kg; 3 pens). The treatments included CON—a basal diet, and SCB—basal diet plus a probiotic (Saccharomyces cerevisiae boulardii CNCM I-1079; 1.0 × 1010 CFU/head/d). Experimental diets were administered for the first 42 d (21 d in the step-up phase and 21 d in the finishing diet −870 g concentrate/kg dry matter [DM]). Subsequently, both treatment groups were transitioned to the same basal diet for an additional 76 d, completing 118 d on feed. Linear regression analysis was conducted for dry matter intake (DMI) data. During the initial 42 d, DMI tended to be higher for SCB (P = 0.09); also bulls fed SCB reached the plateau of the curve at 9.17 kg DMI/d earlier (39 d, R2 = 0.97) than those fed CON (43 d; R2 = 0.96) diets. For the first 42 d, the SCB treatment exhibited higher final weight (393.0 vs. 401.4 kg, P = 0.02), total gain (49.3 vs. 53.5 kg, P = 0.02), daily weight gain (1.124 vs. 1.274 kg, P = 0.02), and G:F (0.174 vs. 0.188, P = 0.04). Over the entire 118-d period, SCB-fed bulls had greater final body weight (509.5 vs. 518.0 kg, P = 0.02), total body weight gain (163.7 vs. 170.3 kg, P = 0.01), and average daily gain (1.366 vs. 1.420 kg, P = 0.01). The feed efficiency of SCB-supplemented bulls was 8.05% higher than CON (P = 0.04), and the final carcass weight was 1.69% greater for animals fed SCB (283.8 vs. 288.6 kg, P = 0.04). Total carcass weight gain (110.9 vs. 114.7 kg) and daily carcass weight gain (0.924 vs. 0.956 kg) tended (P = 0.06) to increase by 3.46% in SCB-fed animals compared with those fed CON. Gain yield, carcass conversion, and carcass yield did not differ between treatments. There were no significant differences in the apparent digestibility of DM, crude protein, neutral detergent fiber, and ether extract between treatments. However, starch digestibility (92.7% vs. 88%) was greater for the control treatment (P < 0.001). Including live Saccharomyces cerevisiae boulardii yeast as a probiotic supplement during the initial 42 d in the feedlot enhanced early-stage growth performance in Nellore bulls. Notably, this supplementation carried over carcass gain over the entire feedlot period.
PubDate: Wed, 19 Jun 2024 00:00:00 GMT
DOI: 10.1093/tas/txae097
Issue No: Vol. 8 (2024)
- National Beef Quality Audit—2022: in-plant assessments of quality and
yield determining carcass characteristics of fed steers and heifers
First page: txae098
Abstract: AbstractThe National Beef Quality Audit – 2022 serves as a benchmark of the current fed steer and heifer population of the U.S. beef industry and allows comparison to previous audits as a method of monitoring industry progress. In-plant cooler assessments and collections of beef carcass data took place from July 2021 to November 2022. During in-plant evaluations, 10% of 1-d production was surveyed for quality and yield indicating characteristics of fed beef carcasses (n = 9,746 beef carcasses). Distributions of sex classes among sampled carcasses were steer (65.0%) and heifer (35.0%), whereas distributions of breed type were native (87.7%), dairy (11.3%), and Bos indicus (0.9%). Mean values were observed for USDA Yield Grades (YG; 3.3), USDA Quality Grade (QG; Choice16), marbling score (Small98), ribeye area (91.0 cm2), adjusted fat thickness (1.49 cm), hot carcass weight (401.9 kg), and KPH (2.5%). Mean overall maturity was A66, with a mean lean maturity of A56 and mean skeletal maturity of A72. There were 28.1% of carcasses identified for use in a USDA-certified beef G-Schedule Program. Defects, such as dark cutting and blood splash, were observed at 1.8% and 0.5%, respectively. Distributions of USDA YG were YG 1 (8.2%), YG 2 (30.7%), YG 3 (40.2%), YG 4 (16.6%), and YG 5 (4.3%). USDA QGs were observed at 7.5% Prime, 69.2% Choice, 16.4% Select, and 6.8% other. The results of this study provide an updated look at the current grading trends of beef carcasses in the United States to drive progress in the fed beef industry.
PubDate: Sat, 15 Jun 2024 00:00:00 GMT
DOI: 10.1093/tas/txae098
Issue No: Vol. 8 (2024)
- A meta-regression analysis to evaluate the effects of narasin on
grow-finish pig performance
First page: txae099
Abstract: Ionophores are feed additives that decrease gram-positive microbial populations by disrupting the ion transfer across cell membranes resulting in improved growth performance. Narasin (Skycis; Elanco Animal Health, Greenfield, IN) is an FDA-approved ionophore utilized for increased rate of weight gain and improved feed efficiency in growing-finishing pigs. A meta-regression analysis was conducted to evaluate the effects of added narasin in growing-finishing pig diets to predict its influence on average daily gain (ADG), feed efficiency (G:F), and carcass yield. A database was developed containing 21 technical reports, abstracts, and refereed papers from 2012 to 2021 representing 35 observations for growth performance data in studies ranging from 35 to 116 d in length (overall data). In addition, within these 35 observations, individual period data were evaluated (143 observations) using weekly, bi-weekly, or monthly performance intervals (period data). Regression model equations were developed, and predictor variables were assessed with a stepwise manual forward selection procedure. The ADG model using the overall data included ADG, ADFI, and G:F of the control group, added narasin dose, and narasin feeding duration categorized as longer or shorter than 65 d. Predictor variables included in the G:F model using overall data were ADG, ADFI, and G:F of the control group and added narasin dose. For carcass yield, the final model included ADFI and G:F of the control group, added narasin dose, and narasin feeding duration of longer than 65 d. In the period model for ADG, the predictors included ADG, ADFI, and G:F of the control group, added narasin dose, and average BW of the control group categorized into greater than or less than 105 kg. For period data for G:F, the model selected ADG, ADFI, and G:F of the control group and added narasin dose. Based on the results, the overall response to added narasin for ADG and G:F was quadratic and tended to decrease as ADG and G:F increased. A similar quadratic response was observed for the individual period data. In summary, using median values from the database for predictor variables, this meta-analysis demonstrated narasin would be expected to improve ADG between 1.06% and 1.65%, G:F between 0.71% and 1.71%, and carcass yield by 0.31% when fed continuously for longer than 65 d.
PubDate: Sat, 15 Jun 2024 00:00:00 GMT
DOI: 10.1093/tas/txae099
Issue No: Vol. 8 (2024)
- Effect of implementing an effective farrowing accommodation hygiene
routine on clinical cases of disease, medication usage, and growth in
suckling and weaned pigs
First page: txae095
Abstract: AbstractThe few studies that have evaluated hygiene routines in farrowing accommodation to date have focused on pathogen elimination from pens, with little attention paid to pig growth and no information provided on pig health or medication usage. This study aimed to determine if implementation of an optimized farrowing accommodation hygiene routine could improve pig health and growth and reduce medication usage pre- and post-weaning (PW). Forty seven sows were blocked on parity, previous litter size and body weight and assigned to two treatments: T1) Basic hygiene: cold water washing only with minimal drying time; T2) Optimized hygiene: use of detergent and a chlorocresol-based disinfectant with a 6-d drying time. Total bacterial counts (TBC), Enterobacteriaceae counts and adenosine triphosphate (ATP) swabs were obtained from different areas within the farrowing pens. Pig growth and medication usage were monitored from birth to slaughter and carcass data were obtained at slaughter. On entry of sows to the farrowing pens, TBC and Enterobacteriaceae counts and ATP concentrations were lower on pen surfaces subjected to the optimized compared to the basic hygiene routine (P < 0.05). Pre-weaning diarrhea prevalence was lower in pigs born into optimal compared to basic hygiene pens (0 vs. 22%; P < 0.001). The number of clinical cases of disease and injections administered to piglets per litter was 75% and 79% less for the optimized compared to the basic hygiene routine, respectively (P < 0.001). This led to reductions of 77% (P < 0.001) and 75% (P < 0.01), respectively in the volume of antibiotics and anti-inflammatories administered per litter in the optimized hygiene group. Pigs from the optimized hygiene treatment were also heavier at weaning (P < 0.01) and their average daily gain (ADG) was higher from day 21 to weaning and days 22 to 49 PW (P < 0.05). However, these growth improvements did not carry through to the finisher period. In conclusion, implementation of an optimized hygiene routine reduced the bacterial load in farrowing pens, leading to a reduction in diarrhea and clinical cases of disease and therefore, medication usage, in suckling pigs. Pig growth was also improved during the suckling and early PW periods. Based on the results, an easily implementable farrowing room hygiene protocol with demonstrable benefits for pig health, growth, and welfare can be provided to farmers.
PubDate: Fri, 14 Jun 2024 00:00:00 GMT
DOI: 10.1093/tas/txae095
Issue No: Vol. 8 (2024)
- Alterations in the rate of fertility, egg viability, and hatch parameters
of adult geese exposed to different breeding methods
First page: txae094
Abstract: AbstractIn a 10-wk study, alterations in the rate of fertility, egg viability, and hatch parameters of adult geese exposed to different breeding methods were investigated. Twenty-four matured geese (4.0 ± 0.45 average weight) were randomly divided into three groups (TNM—natural mating group, TIM—artificial insemination group, TNI—natural mating and insemination group) of two replicates with four geese per replicate in a completely randomized design. Fresh semen collected from six ganders (5.2 ± 0.69 average weight) was pooled and used to inseminate the geese in TIM and TN1 at 0.2Ml at insemination times. The geese in TNM and TNI were allowed to mate naturally. Insemination and mating was done at 3 d interval and eggs from each treatment were collected daily. Incubation of eggs was done weekly, candling and transfer to hatcher were done on day 27 and goslings hatched out on day 30. Fertility, early embryo mortality (EEM), mid embryo mortality (MEM), late embryo mortality (LEM), hatch of fertile eggs (HOF), and hatch of set eggs (HOS) were obtained and analyzed using descriptive statistics and ANOVA and means separated using least significant difference test. Geese in TNI had significantly higher fertility (93.33 ± 10.97%) than TNM (59.67 ± 31.29%) and TIM (83.60 ± 17.14%). The EEM was higher in TIM than in the two other groups while the HOF and HOS were higher in TNM and TNI than in TIM. This study suggests that in comparison with TIM, higher fertility, hatchability, and lower embryo mortality can be obtained when geese are inseminated and naturally mated simultaneously.
PubDate: Fri, 14 Jun 2024 00:00:00 GMT
DOI: 10.1093/tas/txae094
Issue No: Vol. 8 (2024)
- Injecting postpartal gilts or sows with a supraphysiological dose of
oxytocin: effects on sow and piglet performances
First page: txae091
Abstract: AbstractThe goal of this project was to determine the effects of a supraphysiological dose of oxytocin given to gilts or multiparous sows 8 to 12 h after the end of farrowing on the performance of their progeny. Sows from three parity groups (1 = parity 1; 2 = parities 2, 3, and 4; 3 = parities 5 to 14) received no injection (CTL, controls; n = 17, 27, and 23 for parity groups 1, 2, and 3, respectively) or one intramuscular injection of 75 IU of oxytocin (OXY, n = 17, 24, and 26 for parity groups 1, 2, and 3, respectively) 8 to 12 h after birth of the last piglet. Colostrum samples were obtained 8 h after oxytocin injection in 18 sows from parity group 2 (CTL, n = 10; OXY, n = 8). Standard milk composition was measured as well as the Na/K ratio, and IGF-1, IgG, and IgA concentrations. The same sows were used to obtain blood samples from four male piglets of average litter body weight (BW) 8 h post-treatment to measure concentrations of IGF-1, IgG, and IgA. Piglets and sows were weighed at farrowing and weaning (day 21) and sow feed intake and piglet mortality were recorded. There was no effect of OXY on sow or piglet BW at any measured times and percent preweaning piglet mortality was not affected by OXY or parity. First-parity sows had lower BW than multiparous sows at both times (P < 0.001), and piglet average daily gain from birth to weaning was greater in parity group 2 compared with first-parity litters (P < 0.05). Average daily sow feed intake over the first week of lactation tended to be greater in OXY vs CTL sows (P = 0.07), and multiparous sows consumed more feed than first-parity sows on all weeks of lactation (P < 0.001). Eight hours after treatment, there was a tendency for colostral Na to be greater in OXY vs CTL sows (P = 0.06), and none of the measured variables in piglet blood were affected by treatment. In conclusion, injecting 75 IU of oxytocin 8 to 12 h after the birth of the last piglet did not prolong the period of colostrogenesis or improve the growth or survival of piglets and this was consistent across parities.
PubDate: Wed, 12 Jun 2024 00:00:00 GMT
DOI: 10.1093/tas/txae091
Issue No: Vol. 8 (2024)
- Development of an application programming interface to automate
downloading and processing of precision livestock data
First page: txae092
Abstract: AbstractAdvancements in technology have ushered in a new era of sensor-based measurement and management of livestock production systems. These sensor-based technologies have the ability to automatically monitor feeding, growth, and enteric emissions for individual animals across confined and extensive production systems. One challenge with sensor-based technologies is the large amount of data generated, which can be difficult to access, process, visualize, and monitor information in real time to ensure equipment is working properly and animals are utilizing it correctly. A solution to this problem is the development of application programming interfaces (APIs) to automate downloading, visualizing, and summarizing datasets generated from precision livestock technology (PLT). For this methods paper, we develop three APIs and accompanying processes for rapid data acquisition, visualization, systems tracking, and summary statistics for three technologies (SmartScale, SmartFeed, and GreenFeed) manufactured by C-Lock Inc (Rapid City, SD). Program R markdown documents and example datasets are provided to facilitate greater adoption of these techniques and to further advance PLT. The methodology presented successfully downloaded data from the cloud and generated a series of visualizations to conduct systems checks, animal usage rates, and calculate summary statistics. These tools will be essential for further adoption of precision technology. There is huge potential to further leverage APIs to incorporate a wide range of datasets such as weather data, animal locations, and sensor data to facilitate decision-making on time scales relevant to researchers and livestock managers.
PubDate: Fri, 07 Jun 2024 00:00:00 GMT
DOI: 10.1093/tas/txae092
Issue No: Vol. 8 (2024)
- Influence of proportion of Brahman genetics on productivity of
Brahman–Angus cows at weaning
First page: txae093
Abstract: AbstractThis study evaluated the association between the proportion of Brahman genetics and productivity of Brahman–Angus cows at weaning using a 31-yr dataset containing 6,312 cows and 5,405 pregnancies. Cows were contemporaneously reared and enrolled in yearly breeding seasons under subtropical conditions of North-Central Florida. They were evenly distributed in six-breed groups (G) according to the proportion of Brahman genetics: G0% to 19%, G21% to 34%, G38% (Brangus), G41% to 59%, G63% to 78%, and G81% to 100%. The proportion of cows calving (84.9%) did not differ across the six-breed groups. However, cows in the G81% to 100% weaned fewer calves (90.8%) than cows in the G0% to 19% and G21% to 34% (95.7%, each). The weaning rate of cows in the G38% (94.3%), G41% to 59% (94.2%), and G63% to 78% (93.0%) was intermediate between these three breed groups. The preweaning calf mortality was greater for cows in the G81% to 100% (9.2%) than cows in the G0% to 19% and G21% to 34% (4.3%, each), but intermediate for cows in the G38% (5.7%), G41% to 59% (5.8%), and G63% to 78% (7.0%). Cows in the G81% to 100% also weaned lighter calves (220.6 kg) than cows in the G0% to 19% (245.2 kg), G21% to 34% (250.2 kg), G38% (247.9 kg), G41% to 59% (252.5 kg), and G63% to 78% (245.2 kg). Cows in the G0% to 19% weaned lighter calves than cows with 21% to 78% of Brahman genetics. The 205-d adjusted weaning weight evidenced the less productive results of cows in G0% to 19% and G81% to 100% compared with other genetic groups, as they calved at the fastest and slowest rate, respectively. Thus, the 205-d adjusted weaning weight eliminated this bias. Additionally, younger cows weaned lighter calves; and male calves were heavier at weaning than female calves. Both parity order of cow and calf sex altered the magnitude of the described association between breed group of cows and calf weaning weights. Overall, after adjusting for weaning rate and age of calves at weaning, the number of kilograms produced per cow submitted to reproduction was less for cows in the G0% to 19% (191.1 kg) and G81% to 100 (181.8 kg) compared with cows in the G21% to 34 (197.0 kg), G38 (195.9 kg), G41% to 59 (199.7), and G63% to 78 (196.2). Cows in the G81% to 100% were the least productive. Thus, a proportion of Brahman genetics between 21% and 78% ensured superior productivity of Brahman–Angus cows subjected to subtropical conditions.
PubDate: Thu, 06 Jun 2024 00:00:00 GMT
DOI: 10.1093/tas/txae093
Issue No: Vol. 8 (2024)
- Impact of planning horizon length on traits in an economic breeding goal
and ranking of selection candidates in beef cattle
First page: txae090
Abstract: AbstractIn beef production herds, unique situations such as breeding system, economic parameters, and current phenotypic performance can affect the emphasis of traits in the breeding goal and consequently the weighting of traits within a selection index. An often overlooked component of breeding goals is the planning horizon, or the time span to consider the economic impact of a selection decision, that varies between enterprises. A platform for constructing economic selection indexes (iGENDEC) was used to determine the impact of planning horizon length, breeding system, and sale endpoint on the relative emphasis of traits in the breeding goal and the re-ranking of selection candidates. As part of this investigation, the adjustment of phenotypic means for hot carcass weight and planning horizons were used to determine the impact of the relative emphasis on hot carcass weight as its mean approached a predetermined discount threshold. General-purpose indexes were created for animals sold at weaning and slaughter for three breeding systems with six different planning horizons (2, 5, 10, 20, 30, and 50 yr). As planning horizon increased, the relative emphasis on weaning weight or hot carcass weight, which affected revenue, decreased while the relative emphasis on stayability and mature weight increased. As the phenotypic mean for hot carcass weight approached and surpassed a predetermined discount threshold, the relative emphasis decreased before increasing again, once the mean weight surpassed the threshold. Rank correlations between indexes with different sale endpoints was 0.71 ± 0.1. Within a slaughter endpoint, re-ranking occurred between short and long planning horizons (r = 0.78 ± 0.09) while that of a weaning endpoint was less substantial (r = 0.85 ± 0.10). Jacard index scores between indexes with different planning horizons ranged from 39.7% to 87.9% and from 47.9% to 78.7% for weaning and carcass endpoints, respectively, for the top 5% of selection candidates. These results illustrate that the determination of a planning horizon can impact the rank of selection candidates and increases in net profit.
PubDate: Mon, 03 Jun 2024 00:00:00 GMT
DOI: 10.1093/tas/txae090
Issue No: Vol. 8 (2024)
- Influence of differing levels of concentrate on circulating cytokine
concentrations in beef heifers
First page: txae089
Abstract: AbstractComponents of the immune system (e.g., cytokines and chemokines) can influence reproductive efficiency. Characterizing the influence nutrition has on shifts in circulating cytokine concentrations will allow for a better understanding of reproductive efficiency in beef cattle. This study aimed to determine the effect of diet composition on circulating cytokine concentrations of beef heifers. Using a 3 × 3 Latin square design, pubertal Bos taurus-influenced rumen-cannulated heifers (n = 15) were fed a diet based on different concentrate percentages. The treatment period consisted of 28-d feeding periods with a washout interval of 21 d. Treatment groups were fed 100% grass hay (high forage; HF), 60% grass hay with 40% corn-based concentrate (intermediate; INT), and 25% grass hay with 75% corn-based concentrate (high grain; HG). Heifers were offered 2% of their body weight in feed daily. Blood was collected on days 0 and 28 of the treatment period for cytokine analysis. Plasma cytokine concentrations were quantified using RayBiotech Quantibody Bovine Cytokine Array Q1 kit according to manufacturer instructions. Concentrations of interferon gamma-induced protein 10 (IP10) linearly decreased with an increased concentrate diet (P = 0.037). Concentrations of IP10 differed for heifers consuming HF diet vs. HG diet (3,069.52 vs. 1,001.84 ± 669.01 pg/mL, respectively) and heifers consuming INT diet vs. HG diet (2,886.77 vs. 1,001.84 ± 669.01 pg/mL, respectively); however, there were no significant differences in IP10 concentrations between HF and INT heifers. There was a tendency for interleukin-1 family member 5 (IL1F5) concentrations to be lower for heifers consuming the HG diet compared to INT diet (P = 0.08). Results suggest that heifers consuming a high-concentrate diet have lower concentrations of IP10 and IL1F5. Additional research is necessary to better understand the dietary influence on the immune system in developing heifers.
PubDate: Sun, 02 Jun 2024 00:00:00 GMT
DOI: 10.1093/tas/txae089
Issue No: Vol. 8 (2024)
- The effect of a direct-fed microbial (10-G) on live animal performance,
carcass characteristics, and Salmonella prevalence of fed beef heifers
First page: txae086
Abstract: AbstractThe objective of this study was to determine the efficacy of the direct-fed microbial 10-G upon cattle growth performance, liver and lung health, carcass quality, and yield outcomes, as well as prevalence and enumeration of Salmonella in feces and lymph nodes. Fed beef heifers (N = 1,400; initial shrunk body weight [BW] 343.3 ± 36.2 kg) were blocked by the day of arrival and randomly allocated to one of two treatments (0 [negative control, CON] or 2 g of a direct-fed microbial [10-G] that provided 1 billion CFUs per animal per day of Lactobacillus acidophilus, Enterococcus faecium, Pediococcus pentosaceus, L. brevis, and L. plantarum) with 10 pens per treatment. Recto-anal mucosal fecal samples (RAMs; n = 477) and subiliac lymph nodes (SLNs; n = 479) were collected longitudinally at harvest from 23 to 25 heifers per pen. Data were analyzed using mixed models; pen served as the experimental unit; block and harvest date were random effects. No differences were detected in dry matter intake (P = 0.78), final BW (P = 0.64), average daily gain (P = 0.51), gain to feed (P = 0.71), hot carcass weight (P = 0.54), dressed carcass yield (P = 0.52), 12th rib fat depth (P = 0.13), longissimus muscle area (P = 0.62), calculated empty body fat (P = 0.26), or marbling score (P = 0.82). Distributions of liver scores (P ≥ 0.34), quality grades (P ≥ 0.23), and yield grades (P ≥ 0.11) were also not different between treatments. A tendency was detected for more normal lungs (P = 0.08; 10-G = 65.96%, CON = 61.12%) and fewer inflated lungs at harvest for cattle fed 10-G (P = 0.10; 10-G = 0.29%, CON = 1.16%); other lung outcomes did not differ (P ≥ 0.54). Salmonella prevalence did not differ for RAM samples (P = 0.41; 10-G = 97.74%, CON = 96.82%) or SLN (P = 0.22; 10-G = 17.92%, CON = 13.66%). Salmonella concentration of RAM samples (P = 0.25; 10-G = 3.87 log CFU/g, CON = 3.32 log CFU/g) or SLN (P = 0.37; 10-G = 1.46 log CFU/g, CON = 1.14 log CFU/g) also did not differ between treatments at harvest. These results do not demonstrate any difference in live animal performance, carcass characteristics, or Salmonella carriage for heifers fed 10-G.
PubDate: Wed, 29 May 2024 00:00:00 GMT
DOI: 10.1093/tas/txae086
Issue No: Vol. 8 (2024)
- Influence of epinephrine reactivity to stress on meat quality in goats
First page: txae078
Abstract: AbstractThe magnitude of physiological responses to a stressor can vary among individual goats within a herd; however, whether these differences can differentially affect meat quality is not known. This study was conducted to determine the influence of the magnitude of epinephrine response (ER) to acute stress on muscle metabolome and meat quality in goats. Male Spanish goats (6 mo old) were transported for 180 min. (N = 75 goats; 25 goats/d) to impose stress. Blood samples were obtained after transport for analysis of physiological responses. Goats were slaughtered using humane procedures and samples were collected for muscle metabolomics and meat quality analyses. The data obtained from blood and muscle/meat analysis were then categorized based on epinephrine concentrations into low (LE), medium (ME), and high (HE) ER groups (n = 12/ER group). The physiological and meat quality variables were analyzed as a Completely Randomized Design in SAS, and metabolomics data were analyzed using R software. Plasma glucose concentrations were significantly high in the HE group, low in the LE group, and intermediate in the ME group (P < 0.05). However, leukocyte counts and cortisol, norepinephrine, blood urea nitrogen, and creatine concentrations were not different among the ER groups. Muscle (Longissimus dorsi) glycogen concentrations (15 min postmortem) were significantly higher (P < 0.05) in the ME and LE groups than in the HE group. However, postmortem Longissimus muscle pH and temperature (15 min and 24 h), 24 h calpastatin and desmin levels, and rib chop color (L*, a*, and b*), cooking loss, and Warner-Bratzler shear force values were unaffected by ER. Targeted metabolomics analysis of Longissimus muscle (15 min) revealed that diacyl phosphatidylcholines (C38:0; 40:6) and sphingomyelin (C20:2) were significantly different (P < 0.05) among the ER groups, with the concentrations of these metabolites being consistently high in the LE group. These differential muscle metabolite concentrations suggest that ER can influence biochemical pathways associated with cell membrane integrity and signaling. ER had a significant effect on dopamine concentrations, with the levels increasing with increasing levels of ER. The results indicate that differences in epinephrine reactivity can influence selected physiological responses and muscle metabolites; however, it does not significantly influence meat quality attributes.
PubDate: Tue, 28 May 2024 00:00:00 GMT
DOI: 10.1093/tas/txae078
Issue No: Vol. 8 (2024)
- Effects of supplemental methionine sources in finishing pig diets on
growth performance, carcass characteristics, cutting yields, and meat
quality
First page: txae088
Abstract: AbstractSupplemental methionine (Met) is widely used within the swine industry; however, data are limited regarding the effect of Met sources on carcass cutability and meat quality. The objective was to determine the effects of L-Met (LM, 99%), DL-Met (DLM, 99%), or calcium salt of DL-Met hydroxyl analog (MHA, 84%) in finishing pig diets on carcass characteristics and meat quality. At 9 weeks of age, pigs (N = 240) were allocated to 60 single-sex pens for a four-phase finishing trial that lasted 104 d. Pigs were fed a common grower diet until day 56 where pens were randomly allotted to one of the three experimental diets. For the remaining 7 wk of the finisher phase, pigs (BW = 79.9 ± 0.80 kg) were fed diets containing LM, DLM, or MHA, with the supplemental Met source providing 25% of standardized ileal digestible (SID) Met + cysteine (Cys) requirement based on 65% bioefficacy for MHA in comparison with LM or DLM. One pig per pen was slaughtered at the study conclusion (on day 104), and the left sides of carcasses were fabricated into subprimal cuts to determine carcass-cutting yields. Loin quality including proximate composition and shear force were measured. Hot carcass weight was not different (P = 0.34) between treatments (LM 104.5 kg; DLM 103.0 kg; MHA 101.5 kg), moreover, loin eye area was not different (P = 0.98) between treatments (LM 52.65 cm²; DLM 52.49 cm²; MHA 52.81 cm²). Boneless carcass-cutting yield was not different (P = 0.56) between treatments (LM 54.97 kg; DLM 54.82 kg; MHA 54.52 kg). Loin pH was not different (P = 0.24) between treatments (LM 5.45; DLM 5.48; MHA 5.45). However, drip loss tended to be reduced (P = 0.11) by the DLM treatment (5.58%) compared with LM (7.03%) and MHA (6.68%) treatments. Shear force was not different (P = 0.85) between treatments (LM 3.03 kg; DLM 3.06 kg; MHA 3.10 kg). However, cook loss tended to be reduced (P = 0.06) by the DLM treatment (16.20%) compared with LM (18.18%) and MHA (18.50%) treatments. These data suggest that only minimal differences in carcass cutability and meat quality can be attributed to Met source in finishing pig diets when using 65% bioefficacy for MHA relative to L-Met or DL-Met.
PubDate: Mon, 27 May 2024 00:00:00 GMT
DOI: 10.1093/tas/txae088
Issue No: Vol. 8 (2024)
- Effect of acidosis in the late-finishing phase on rumen fermentation in
feedlot steers
First page: txae084
Abstract: AbstractThe objective was to determine the effects of induced acidosis in the late-finishing phase on rumen fermentation in feedlot steers. Eleven ruminally cannulated steers (body weight [BW] = 795 kg ± 54) were blocked into two groups based on initial BW. For 195 d prior to the start of the study, cattle were consuming a basal finishing diet (60% dry-rolled corn, 15% modified distillers grains, 15% corn silage, and 10% ground corn-based supplement). Steers were randomly assigned to one of the two treatments: control (CON), or induced acidosis (ACD). Both treatments were fasted for 24 h then fed the basal finishing diet. Steers on the ACD treatment received 0.05% of BW of wheat starch via rumen cannula at 0800 and 2000 hours on day 1 and ad libitum refeeding following the fast. On days 1 and 2, CON steers were provided 25% of allotted feed every 6 h. Rumen fluid was collected every 4 h during the challenge period (hours 0 to 48), and 0, 6, and 12 h after feeding during the recovery period (hours 54 to 96). Rumen fluid was analyzed for pH, ammonia, volatile fatty acids (VFA), and lactate. Fecal grab samples were collected every 8 h to determine fecal pH. A treatment × day interaction (P = 0.03) was observed for dry matter intake during the challenge period with steers on the ACD treatments consuming more on day 1 than CON steers. Intake was not different on day 2 (P = 0.88). A treatment × hour effect (P < 0.01) was observed for ruminal pH during the challenge period with the ACD steers having a lesser pH than CON from hours 12 to 32. Duration of time below a pH of 5.6 during the challenge period was greater (P < 0.01) for ACD steers than CON. During the challenge period, a treatment × time interaction (P = 0.04) was observed for total VFA concentration with ACD steers having greater total VFA concentration from hours 12 to 36. Acetate to propionate ratio (A:P) was affected by treatment × hour (P = 0.04) with CON steers having greater A:P from hours 28 to 48. Rumen ammonia and lactate concentrations did not differ (P ≥ 0.25) between treatments or the interaction with time. Challenge and recovery period fecal pH were not affected (P ≥ 0.13) by treatment, time, or their interaction. Recovery period ruminal pH was not different (P = 0.99) between treatments. For the recovery period, total VFA and ammonia concentration were not affected by treatment, time, or their interaction (P ≥ 0.07). Ruminal pH and VFA were affected in the initial 48 h of induced acidosis in the late-finishing phase.
PubDate: Mon, 27 May 2024 00:00:00 GMT
DOI: 10.1093/tas/txae084
Issue No: Vol. 8 (2024)
- A review of calcium and phosphorus requirement estimates for gestating and
lactating sows
First page: txae087
Abstract: AbstractCalcium (Ca) and phosphorus (P) are minerals involved in biological functions and essential structural components of the skeleton. The body tightly regulates Ca and P to maintain homeostasis. Maternal needs for Ca and P increase during gestation and lactation to support conceptus growth and milk synthesis. Litter size and litter average daily gain (ADG) have a large effect on Ca and P requirements for sows because as they increase, the requirements increase due to a greater need from the sow. The objective of this review was to summarize published literature on Ca and P requirements in gestating and lactating sows derived from empirical data and factorial models. A total of nine empirical studies and seven factorial models were reviewed for determining the Ca and P requirements in gestation. For lactation, there were six empirical studies and seven factorial models reviewed. Empirical studies determined requirements based on the observed effect of Ca and P on bone mineralization, sow and litter performance, and milk characteristics. Factorial models generated equations to estimate Ca and P requirements using the main components of maintenance, fetal and placental growth, and maternal retention in gestation. The main components for factorial equations in lactation include maintenance and milk production. In gestation, the standardized total tract digestible phosphorus (STTD P) requirement estimates from empirical studies range from 5.4 to 9.5 g/d with total Ca ranging from 12.9 to 18.6 g/d to maximize bone measurements or performance criteria. According to the factorial models, the requirements increase throughout gestation to meet the needs of the growing fetuses and range from 7.6 to 10.6 g/d and 18.4 to 38.2 g/d of STTD P and total Ca, respectively, on day 114 of gestation for parity 1 sows. During lactation, STTD P requirement estimates from empirical studies ranged from 8.5 to 22.1 g/d and total Ca ranged from 21.2 to 50.4 g/d. For the lactation factorial models, STTD P requirements ranged from 14.2 to 25.1 g/d for STTD P and 28.4 to 55.6 g/d for total Ca for parity 1 sows with a litter size of 15 pigs. The large variation in requirement estimates makes it difficult to define Ca and P requirements; however, a minimum level of 6.0 and 22.1 g/d of STTD P during gestation and lactation, respectively, appears to be adequate to meet basal requirements. The limited data and high variation indicate a need for future research evaluating Ca and P requirements for gestating and lactating sows.
PubDate: Thu, 23 May 2024 00:00:00 GMT
DOI: 10.1093/tas/txae087
Issue No: Vol. 8 (2024)
- Evaluating increasing levels of sodium diformate in diets for nursery and
finishing pigs on growth performance, fecal dry matter, and carcass
characteristics
First page: txae085
Abstract: AbstractTwo studies were conducted to evaluate the effects of sodium diformate in swine diets. For Exp. 1, 360 barrows (DNA 200 × 400; initially 5.9 ± 0.06 kg) were used in a 38-d study. At weaning, pigs were randomly assigned to pens with five pigs per pen. Each pen was allocated to one of six treatments with 12 pens per treatment. Treatments were formulated to provide none, 0.40%, 0.60%, 0.80%, 1.00%, or 1.20% sodium diformate added at the expense of corn. Diets were fed in three phases: phase 1 from weaning to day 9, phase 2 from days 9 to 24, and phase 3 from days 24 to 38. From days 0 to 24 (phases 1 and 2), increasing sodium diformate increased (linear, P = 0.001) gain-to-feed (G:F). However, sodium diformate did not affect average daily gain (ADG) or average daily feed intake (ADFI). From days 24 to 38 (phase 3) and overall (days 0 to 38), there was no evidence of differences due to increasing sodium diformate for any growth response criteria. There was no evidence for differences in fecal dry matter (DM) on day 9. However, fecal DM decreased (linear, P < 0.05; quadratic, P = 0.097) as sodium diformate increased on day 24. In Exp. 2, 2,200 pigs (Duroc sire [PIC 800 or DNA 600] × PIC Camborough; initially 24.2 ± 0.30 kg) were used in a 117-d growth trial. Pens of pigs (25 pigs per pen) were randomly assigned to one of four treatments with 22 pens per treatment. Treatments were formulated with additions of none, 0.25%, 0.50%, or 0.75% sodium diformate. Diets were fed in six phases from 24 to 141 kg. For period 1 (days 0 to 32), ADFI tended to decrease then increase (quadratic, P = 0.081) with increasing sodium diformate, whereas G:F increased then decreased (quadratic, P < 0.001) with increasing sodium diformate. For period 2 (days 32 to 60), there was no evidence for differences in ADG or ADFI; however, there was a tendency for G:F to increase then decrease (quadratic, P = 0.093) with increasing sodium diformate. From days 60 to 93, increasing sodium diformate increased (linear, P < 0.01) ADG and ADFI. From days 93 to 117, increasing sodium diformate increased (linear, P < 0.05) ADG, ADFI, and G:F. Overall (days 0 to 117), pigs fed increasing sodium diformate had increased (linear, P < 0.01) ADG and a tendency for increased (linear, P = 0.075) ADFI; however, there was no evidence for differences in G:F. There were no treatment differences for any carcass characteristic. In summary, increasing sodium diformate may increase G:F in the early nursery and improve ADG after day 60 (approximately 82 kg) in the finishing period.
PubDate: Sat, 18 May 2024 00:00:00 GMT
DOI: 10.1093/tas/txae085
Issue No: Vol. 8 (2024)
- Effects of Trace Mineral Injections on Measures of Growth and Trace
Mineral Status of Primiparous Cows and their Calves
First page: txae068
Abstract: AbstractThe objective of this study was to evaluate the effects of injectable trace minerals (ITM) administrations at strategic moments in the beef cattle production cycle. At calving, 50 primiparous cows (Angus × Hereford) and their calves were randomly assigned to 1 of 2 treatments: 1) ITM: cattle assigned to the ITM treatment received an ITM injection at calving and a subsequent administration at breeding (cattle over 2 yr: 1.0 mL/90 kg body weight [BW]; calves: 1.0 mL/45 kg BW); or 2) Control: cattle assigned to the control treatment were administered with saline following the same procedure as the cattle assigned to the ITM treatment. Body weight, blood, and liver samples were collected from dams and calves at multiple time points to evaluate the growth and mineral status of cow–calf pairs. All variables were analyzed using the MIXED procedure of SAS. A treatment effect (P = 0.02) was observed for Cu liver concentration of primiparous cows at breeding. Cows assigned to ITM treatment had greater Cu status than cohorts assigned to Control treatment. No treatment effects were observed for the mineral status or growth of calves. The administration of ITM to primiparous cows enhanced Cu status when grazing Cu forages scarce of Cu.
PubDate: Wed, 15 May 2024 00:00:00 GMT
DOI: 10.1093/tas/txae068
Issue No: Vol. 8 (2024)
- Effect of wheat middling incorporation into wet corn distillers grains
with solubles on apparent diet digestibility and ruminal fermentation
characteristics in growing and finishing diets
First page: txae083
Abstract: AbstractTwo separate cross-over experiments were conducted to evaluate the effects of incorporating wheat middlings into wet corn distillers grains with solubles (WDGS) on apparent diet digestibility and ruminal fermentation characteristics in growing and finishing diets. In experiment 1, four ruminally cannulated heifers (313 ± 42.9 kg) were limit fed a high-energy growing diet that included WDGS (CON) or WDGS + wheat middlings (CON + WM) at 40% of diet dry matter (DM). The diet also contained (DM basis) 39.5% dry-rolled corn, 7.5% supplement, and 13% warm-season grass hay. In experiment 2, four ruminally cannulated Holstein steers (321 ± 17.4 kg) were fed a finishing diet that included WDGS (CON) or WDGS + wheat middlings (CON + WM) at 30% of diet DM. The diet also contained (DM basis) 60.3% dry-rolled corn, 2.7% supplement, and 7.0% warm-season grass hay. Experiments consisted of two 15-d periods that were conducted concurrently. Each period included 10 d of diet adaptation, 4 d of fecal collection, and 1 d of ruminal fluid collection. Fecal samples were collected on days 11 to 14 of each period and composite samples were analyzed for chromium to estimate apparent diet digestibility. On day 15, ruminal fluid samples were collected prior to feeding and again at 2, 4, 6, 8, 12, 18, and 24-h post-feeding. In experiment 1, DM, organic matter (OM), neutral detergent fiber (NDF), and acid detergent fiber (ADF) intake did not differ (P ≥ 0.11) between diets; however, starch intake was greater (P = 0.03) for heifers fed CON + WM compared with CON. Apparent DM, OM, NDF, and starch digestibilities were similar between diets (P ≥ 0.13), but feeding CON + WM tended to lead to lesser (P = 0.06) apparent ADF digestibility. Ruminal pH and total volatile fatty acid concentrations did not differ between diets (P ≥ 0.16); however, ruminal ammonia concentrations tended to be less (P = 0.09) for CON + WM compared with CON. In experiment 2, DM intake did not differ (P = 0.65) between diets. Apparent DM digestibility was greater (P = 0.01) for CON + WM compared with CON but the difference was small. Intake and apparent digestibility of OM, NDF, ADF, and starch did not differ (P ≥ 0.25) between diets. Ruminal ammonia concentrations were lesser (P = 0.03) while ruminal pH was greater (P = 0.02) for CON + WM compared with CON. Overall, incorporation of wheat middlings into WDGS had minimal impacts on feed intake, apparent diet digestibility, and ruminal fermentation characteristics when fed to growing and finishing cattle.
PubDate: Tue, 14 May 2024 00:00:00 GMT
DOI: 10.1093/tas/txae083
Issue No: Vol. 8 (2024)
- Models to predict nitrogen excretion from beef cattle fed a wide range of
diets compiled from South America
First page: txae072
Abstract: AbstractThe objective of this meta-analysis was to develop and evaluate models for predicting nitrogen (N) excretion in feces, urine, and manure in beef cattle in South America. The study incorporated a total of 1,116 individual observations of N excretion in feces and 939 individual observations of N excretion in feces and in urine (g/d), representing a diverse range of diets, animal genotypes, and management conditions in South America. The dataset also included data on dry matter intake (DMI; kg/d) and nitrogen intake (NI; g/d), concentrations of dietary components, as well as average daily gain (ADG; g/d) and average body weight (BW; kg). Models were derived using linear mixed-effects regression with a random intercept for the study. Fecal N excretion was positively associated with DMI, NI, nonfibrous carbohydrates, average BW, and ADG and negatively associated with EE and CP concentration in the diet. The univariate model predicting fecal N excretion based on DMI (model 1) performed slightly better than the univariate model, which used NI as a predictor variable (model 2) with a root mean square error (RMSE) of 38.0 vs. 39.2%, the RMSE-observations SD ratio (RSR) of 0.81 vs. 0.84, and concordance correlation coefficient (CCC) of 0.53 vs. 0.50, respectively. Models predicting urinary N excretion were less accurate than those derived to predict fecal N excretion, with an average RMSE of 43.7% vs. 37.0%, respectively. Urinary and manure N excretion were positively associated with DMI, NI, CP, average BW, and ADG and negatively associated with neutral detergent fiber concentration in the diet. As opposed to fecal N excretion, the univariate model predicting urinary N excretion using NI (model 10) performed slightly better than the univariate model using DMI (model 9) as predictor variable with an RMSE of 36.0% vs. 39.7%, RSR 0.85 vs. 0.93, and CCC of 0.43 vs. 0.29, respectively. The models developed in this study are applicable for predicting N excretion in beef cattle across a broad spectrum of dietary compositions and animal genotypes in South America. The univariate model using DMI as a predictor is recommended for fecal N prediction, while the univariate model using NI is recommended for predicting urinary and manure N excretion because the use of more complex models resulted in little to no benefits. However, it may be more useful to consider more complex models that incorporate nutrient intakes and diet composition for decision-making when N excretion is a factor to be considered. Three extant equations evaluated in this study have the potential to be used in tropical conditions typical of South America to predict fecal N excretion with good precision and accuracy. However, none of the extant equations are recommended for predicting urine or manure N excretion because of their high RMSE, and low precision and accuracy.
PubDate: Thu, 09 May 2024 00:00:00 GMT
DOI: 10.1093/tas/txae072
Issue No: Vol. 8 (2024)
- Effect of traditional roughage-based or limit-fed, high-energy diets on
growth performance and digestion in newly received growing cattle and
subsequent implications on feedlot growth performance and carcass
characteristics
First page: txae082
Abstract: AbstractThe objective was to determine the effects of ad libitum-fed roughage-based diets or limit-fed high-energy diets on growth performance, behavior, health, and digestion in newly received growing cattle and subsequent implications on feedlot growth performance and carcass characteristics. In experiment 1, 409 crossbred heifers (initial body weight [BW] = 279 ± 24 kg) in 32 pens were used in a randomized block design. Heifers were fed one of two dietary treatments: a total mixed ration with 0.99 Mcal net energy for gain (NEg)/kg dry matter (DM) fed ad libitum (0.99AL) or 1.32 Mcal NEg/kg DM limit-fed at 85% of intake of heifers fed 0.99AL (1.32LF85%). Both diets contained 40% DM as a branded wet corn gluten feed. In experiment 2, 370 crossbred heifers (initial BW = 225 ± 20 kg) were used in a randomized block design and were fed a diet formulated to contain 0.99 Mcal of NEg/kg DM for ad libitum intake or a diet formulated to contain 1.32 Mcal of NEg/kg DM and fed at 2.2% of BW daily (DM basis; 1.32LF2.2). For experiments 1 and 2, treatment integrity was maintained through the finishing phase where cattle were fed a common diet. Cattle were sorted by BW into heavy and light groups prior to finishing, with light cattle fed longer than heavy cattle to reach similar harvest BW. In experiment 3, eight ruminally cannulated heifers (average BW = 305 ± 23 kg) were used in a 2-period cross-over design and fed treatments from experiment 1 to assess digestibility and ruminal fermentation characteristics. Gain:feed was 47% and 35% greater (P < 0.01) in experiments 1 and 2, respectively, for limit-fed heifers compared with 0.99AL heifers. Rumination time was greater (P < 0.01) for 0.99AL compared with limit-fed treatments in experiments 1 and 2. Activity was greater (P < 0.01) for 1.32LF2.2 than for 0.99AL in experiment 2. In experiment 1, more (P = 0.03) carcasses from light-sort heifers than carcasses from heavy-sort heifers had livers with large, active abscesses. In experiment 2, finishing phase morbidity was greater (P < 0.01) for 1.32LF2.2 than for 0.99AL. Light-sort groups had fewer (P < 0.01) edible livers than heavy-sort groups, suggesting that greater number of days on feed may increase the risk of liver abscess prevalence and condemnation. In experiment 3, apparent total-tract DM and organic matter digestibilities were greater (P < 0.01) for 1.32LF85% than for 0.99AL. Overall, dietary treatments during the growing phase had little carryover effect on feedlot growth performance, carcass characteristics, or liver abscesses prevalence at harvest.
PubDate: Wed, 08 May 2024 00:00:00 GMT
DOI: 10.1093/tas/txae082
Issue No: Vol. 8 (2024)
- Effect of extended days on feed on carcass gain, efficiency, and quality
of individually fed beef steers
First page: txae081
Abstract: AbstractCrossbred steers (n = 114, initial BW = 334 kg; SEM = 5 kg) were serially harvested to evaluate the change in carcass composition by feeding cattle 21 or 42 d longer than the 2014 industry average subjective measure of finish, 1.27 cm of 12th rib fat thickness. Carcass ultrasound measurements were collected on 76 steers at 1, 78, and 134 days on feed (DOF) to project appropriate harvest date. Steers were sorted into three harvest groups, and serially harvested at 142, 163, or 185 DOF, with the first harvest date selected based on an estimated 12th rib fat thickness of 1.27 cm via ultrasound measurement. Steers were fed using an individual animal feeding system, to determine individual performance metrics. Steer DMI did not differ (P ≥ 0.31) between harvest groups, while carcass-adjusted ADG and G:F decreased linearly (P ≤ 0.04) as DOF increased. Carcass weight increased linearly (P < 0.01) as DOF increased from 142 to 185 DOF, with steers gaining an additional 36 kg of HCW when fed an additional 42 DOF. Carcass LM area quadratically increased (P = 0.04) to 163 DOF and remained constant to 185 DOF. Marbling score was not different (P = 0.14) between harvest groups; however, the opportunity to grade USDA Premium Choice was improved for steers fed to 185 DOF. Calculated YG and 12th rib fat thickness increased linearly (P < 0.01) as DOF increased, with distributions across YG 1 through 5 differing between harvest groups (P < 0.01), and 185-d carcasses having the greatest frequency of YG 4 carcasses. As cattle are fed for additional DOF, live ADG and G:F decline, while HCW and LM area increase.
PubDate: Wed, 08 May 2024 00:00:00 GMT
DOI: 10.1093/tas/txae081
Issue No: Vol. 8 (2024)
- Evaluation of Elnady preserved tissues as a teaching aid for undergraduate
animal science courses
First page: txae077
Abstract: AbstractThe use of tissue specimens for undergraduate instruction is a very valuable tool. However, fresh tissue specimens are not always available and many common preservation techniques can result in discoloration, offensive odors, and/or dangerous chemical residues. The Elnady Technique was developed as a means to produce tissue specimens that “are realistic, durable, have no offensive odor, and are dry, soft and flexible” (Elnady, F.A. 2016 The Elnady Technique: An innovative, new method for tissue preservation. Altex. 33:237-242. doi:10.14573/altex.1511091). Briefly for soft tissue, specimens were preserved by fixing in formalin. The tissue specimen was then dehydrated with a series of acetone baths. Once the tissue was fully dehydrated, the specimen was impregnated in glycerin. Excess glycerin was then removed by draining followed by immersion in cornstarch. Cornstarch residue was removed with a soft brush, and the specimen was stored in a plastic bag. Multiple specimens (including the female reproductive tract of the cat, goat, horse, and sow; digestive tract of cat, chicken, and dog; 1-day-old lamb stomach; goat rumen, reticulum, omasum, and abomasum; and sheep heart and kidney) have been preserved and used in various animal science course laboratories (126 laboratory sections and 1,696 students at Berry College). Some of the specimens have been in use for seven years and are still in usable condition. Anonymously surveyed Berry College Animal Science Faculty strongly agreed or agreed that Elnady preserved tissues are a useful teaching aid (n = 5). The Elnady Technique has proven to be a useful means of preserving tissue samples used in undergraduate animal science courses.
PubDate: Tue, 07 May 2024 00:00:00 GMT
DOI: 10.1093/tas/txae077
Issue No: Vol. 8 (2024)
- Lupine-induced crooked calf syndrome: mitigation through intermittent
grazing management of cattle
First page: txae079
Abstract: AbstractLupines are responsible for a condition in cattle referred to as “crooked calf syndrome” (CCS) that occurs when pregnant cattle graze teratogenic lupines. A proposed management strategy to limit these types of birth defects includes utilizing an intermittent grazing schedule to allow short durations of grazing lupine-infested areas interrupted by movement to a lupine-free pasture. The objective of this study was to determine if an intermittent schedule of ten continuous days of lupine treatment followed by 5 d off treatment would be sufficient to decrease, or prevent, the incidence of lupine-induced malformations. Continuous dosing of the teratogenic lupine (Lupinus leucophyllus) to pregnant cows for 30 d during the most susceptible stage of pregnancy (gestation days 40 to 70) resulted in severe skeletal birth defects in their calves. However, intermittent dosing of the teratogenic lupine demonstrated that interrupted intake of lupine reduced the severity, or eliminated, permanent skeletal malformations in calves born to cows dosed lupine. Toxicokinetic and ultrasound data demonstrated a clear inverse correlation between serum anagyrine (the primary teratogenic alkaloid in some lupines) concentrations in the dam and fetal movement. In the intermittent group, fetal movement quickly returned to normal after lupine feeding stopped and remained normal until lupine treatment resumed. Therefore, interrupting lupine intake for at least 5 d through an intermittent grazing program could reduce the severity of the CCS. Furthermore, this method would allow ranchers to move cattle back into lupine pastures after a brief interruption, which would allow for more efficient utilization of forage resources.
PubDate: Tue, 07 May 2024 00:00:00 GMT
DOI: 10.1093/tas/txae079
Issue No: Vol. 8 (2024)
- Effects of feeding α-amylase-expressed corn silage and grain on
performance, enteric methane production, and carcass characteristics in
beef steers
First page: txae080
Abstract: AbstractAn experiment was conducted to evaluate the effects of feeding Enogen feed corn (EFC) silage or EFC grain with different grain processing (dry-rolled corn vs. whole-shelled corn) in feedlot cattle diets. Total 68 Angus cross-bred steers were blocked by body weight and the treatments (diets) were randomly assigned to steers in each block: a basal diet with isoline corn silage and isoline dry-rolled corn grain (IIR); the basal diet with EFC silage and isoline dry-rolled corn grain (EIR); the basal diet with EFC silage and EFC dry-rolled grain (EER); and the basal diet with EFC silage and EFC whole-shelled grain (EEW). Isoline refers to the isogenic counterpart of Enogen corn silage or grain. Steers received the assigned treatment over 32 wk of the entire experiment (backgrounding and finishing) until harvested. Part of the steers (eight blocks) in each treatment were used to measure CH4 production (g/d) using the GreenFeed and CH4 production per unit of DMI. All data were analyzed using a mixed procedure of SAS in a randomized complete block design, considering diet as a fixed effect and block as a random effect. Steers fed the EIR diet increased (P = 0.03) DMI compared to IIR during the backgrounding phase. However, feeding EFC silage or grain did not affect body weight, average daily gain, and feed efficiency during backgrounding and finishing phases. Feeding EEW decreased (P ≤ 0.05) body weight, average daily gain, feed efficiency, and tended to decrease (P = 0.06) hot carcass weight compared to EER during the finishing phase. Methane production per unit of DMI decreased (P = 0.02) for steers fed EIR compared with steers fed IIR only during the backgrounding phase. Feeding EFC grain had no effect on CH4 production (g/d) in both phases. In conclusion, feeding EFC silage or grain did not improve the performance of beef steers during the backgrounding and finishing phases in the current experiment condition. Methane production per unit of DMI was reduced for steers fed EFC silage compared with isoline corn silage only during the backgrounding phase.
PubDate: Tue, 07 May 2024 00:00:00 GMT
DOI: 10.1093/tas/txae080
Issue No: Vol. 8 (2024)
- Lessons learned from using wild-caught and captive-reared lesser scaup
(Aythya affinis) in captive experiments
First page: txae076
Abstract: AbstractWaterfowl are housed in captivity for research studies that are infeasible in the wild. Accommodating the unique requirements of semi-aquatic species in captivity while meeting experimental design criteria for research questions can be challenging and may have unknown effects on animal health. Thus, testing and standardizing best husbandry and care practices for waterfowl is necessary to facilitate proper husbandry and humane care while ensuring reliable and repeatable research results. To inform husbandry practices for captive-reared and wild-caught lesser scaup (Aythya affinis; hereafter, scaup), we assessed body mass and fat composition across two different aspects of husbandry, source population (captive-reared or wild caught), and housing densities (birds/m2). Our results suggest that housing scaup at low densities (≤0.6 m2/bird, P = 0.049) relative to other species can minimize negative health effects. Captive-reared scaup were heavier (P = 0.027) with greater body fat (P < 0.001) and exhibited fewer signs of stress during handling than wild-caught scaup. In our experience, scaup which are captive-reared from eggs collected in the wild were better for long-term captivity studies as they maintained body mass between and recovered lost body mass following trials. Researchers would benefit from carefully evaluating the tradeoffs of using short- and long-term captive methods on their research question before designing projects, husbandry practices, and housing facilities for waterfowl.
PubDate: Sat, 04 May 2024 00:00:00 GMT
DOI: 10.1093/tas/txae076
Issue No: Vol. 8 (2024)
- Variations in colostrum metabolite profiles in association with sow parity
First page: txae062
Abstract: AbstractInformation about the full spectrum of metabolites present in porcine colostrum and factors that influence metabolite abundances is still incomplete. Parity number appears to modulate the concentration of single metabolites in colostrum. This study aimed to 1) characterize the metabolome composition and 2) assess the effect of parity on metabolite profiles in porcine colostrum. Sows (n = 20) were divided into three parity groups: A) sows in parity 1 and 2 (n = 8), B) sows in parity 3 and 4 (n = 6), and C) sows in parity 5 and 6 (n = 6). Colostrum was collected within 12 h after parturition. A total of 125 metabolites were identified using targeted reversed-phase high-performance liquid chromatography-tandem mass spectrometry and anion-exchange chromatography-high resolution mass spectrometry. Gas chromatography additionally identified 19 fatty acids (FAs). Across parities, colostrum was rich in creatine and creatinine, 1,3-dioleyl-2-palmitatoylglycerol, 1,3-dipalmitoyl-2-oleoylglycerol, and sialyllactose. Alterations in colostrum concentrations were found for eight metabolites among parity groups (P < 0.05) but the effects were not linear. For instance, colostrum from parity group C comprised 75.4% more valine but 15.7%, 34.1%, and 47.9% less citric, pyruvic, and pyroglutamic acid, respectively, compared to group A (P < 0.05). By contrast, colostrum from parity group B contained 39.5% more spermidine than from group A (P < 0.05). Of the FAs, C18:1, C16:0, and C18:2 n6 were the main FAs across parities. Parity affected four FAs (C18:3n3, C14:1, C17:0ai, and C17:1), including 43.1% less α-linolenic acid (C18:3n3) in colostrum from parity group C compared to groups A and B (P < 0.05). Signature feature ranking identified 1-stearoyl-2-hydroxy-sn-glycero-3-phosphatidylcholine and the secondary bile acid hyodeoxycholic acid as the most discriminative metabolites, showing a higher variable importance in the projection score in colostrum from parity group A than from groups B and C. Overall, results provided a comprehensive overview about the metabolome composition of sow colostrum. The consequences of the changes in colostrum metabolites with increasing parity for the nutrient supply of the piglets should be investigated in the future. The knowledge gained in this study could be used to optimize feeding strategies for sows.
PubDate: Fri, 03 May 2024 00:00:00 GMT
DOI: 10.1093/tas/txae062
Issue No: Vol. 8 (2024)
- Effects of zinc supplementation and implant abscess on the immune system
and growth performance of growing beef steers
First page: txae075
Abstract: AbstractSeventy-two Angus-cross steers (261 ± 14 kg) were utilized to determine the effects of supplemental Zn sulfate on growth, trace mineral status, circulating immune cells, and functional innate immune responses. Steers were stratified by weight and implanted with a Component E-S with Tylan implant (Elanco Animal Health, Greenfield, IN) on day 0. Dietary treatments included: control (CON; no supplemental Zn), Zn100 (100 mg supplemental Zn/kg DM), and Zn150 (150 mg supplemental Zn/kg DM). Analyzed dietary concentrations of Zn were 58, 160, and 207 mg Zn/kg DM, respectively. On days 13 and 57, blood from nine steers per treatment was collected for immune analyses (cell phenotyping and response to stimulus). On day 16, implant abscesses were evaluated by palpation and visual appraisal. Sixty percent of steers had abscesses; however, there were no differences in abscess prevalence due to treatment (P = 0.67). Data were analyzed as a split-plot design using the Mixed procedure of SAS 9.4 (Cary, NC) with effects of dietary treatment, abscess, and their interaction. There was a tendency (treatment × abscess; P ≤ 0.09) for steers without abscesses to have greater average daily gain (ADG; treatment × abscess P = 0.06) and gain:feed (G:F; treatment × abscess P = 0.09) from d 14 to 27 in CON and Zn100 while within Zn150 steers without abscesses tended to have lesser ADG and G:F than abscessed steers. There were no other treatment × abscess effects for growth performance, but steers with abscesses tended to have decreased final body weight (P = 0.10) and overall G:F (days 0 to 57; P = 0.08). There was no interaction of treatment and abscess on immune cell populations on days 13 or 58 (treatment × abscess P ≥ 0.11). On day 13, Zn150 steers had increased CD45RO + gamma delta (P = 0.04) T cells. Abscessed steers had increased CD21 + B cells (P = 0.03) and tended to have increased CD21 + (P = 0.07) and CD21 + MHCIIhi (P = 0.07) B cells in circulation. This study shows zinc supplementation and implant abscesses can alter the immune system and growth performance of growing beef steers.
PubDate: Thu, 02 May 2024 00:00:00 GMT
DOI: 10.1093/tas/txae075
Issue No: Vol. 8 (2024)
- Determining muscle plasticity and meat quality development of low-input
extended fed market-ready steers
First page: txae064
Abstract: AbstractIn March 2020, the World Health Organization declared COVID-19 a pandemic, which ultimately led to many meat processors temporarily shutting down or reducing processing capacity. This backlog in processing capacity forced many feedlots to retain cattle for longer periods of time and assume the risk of major market fluctuations. The aim of this study was to understand how a dietary insult affects meat quality and muscle metabolism in market-ready steers (590 kg). Sixteen market-ready (590 kg) commercial Angus crossbred steers were subjected to a maintenance diet of either forage or grain for 60 d. Longissimus lumborum (LL) muscle samples were collected immediately postmortem and processed for characteristics reflecting the underlying muscle fiber type and energy state of the tissue. Despite cattle being subjected to a 60-d feeding period, there were no detectable differences (P > 0.05) in carcass characteristics, color of lean, or ultimate pH (pHu). Moreover, our data show that muscle plasticity is rather resilient, as reflected by lack of significance (P > 0.05) in oxidative and glycolytic enzymes, myosin heavy chain isoforms (MyHC), myoglobin, and mitochondrial DNA (mtDNA) contents. These data show that market-ready steers are capable of withstanding a low-input feeding strategy up to 60 d without dramatically impacting underlying muscle characteristics and meat quality development.
PubDate: Thu, 02 May 2024 00:00:00 GMT
DOI: 10.1093/tas/txae064
Issue No: Vol. 8 (2024)
- Relationship of length of the estrous cycle to antral follicle number in
crossbred beef heifers
First page: txae074
Abstract: AbstractLength of the menstrual cycle was positively associated with antral follicle number in women. If this pattern is consistent in cattle, a value-added benefit to using automated activity monitors to determine estrous status could be the ability to predict antral follicle count (AFC). We, therefore, hypothesized that as inter-estrous interval increased ultrasonographic AFC would be greater in crossbred beef heifers. Over 3 yr, crossbred beef heifers (n = 1,394) were fitted with automated activity monitors for 81 d. From days 42 to 46, heifers were submitted for ultrasonographic examination to determine AFC. From days 60 to 81, heifers were visually observed twice daily for 45 min for signs of behavioral estrus. Heifers that had a behavioral estrus that coincided with a sensor-based estrus and had a previous sensor-based estrus between 15 and 26 d earlier were used for the analysis (n = 850). A combination of regression analyses and correlation analyses were applied to understand the association between data collected by sensors and follicle number determined by ultrasonographic examination. Antral follicle count was analyzed using the GLM procedure of SAS with estrous cycle length (15 to 26 d) as a fixed effect. Estrus was more likely to initiate in the early morning hours and peak activity was greater (P < 0.0001) when estrus initiated between 0200 and 0800 hours then when estrus initiated at other times of the day. Antral follicle count did not differ due to length of the estrous cycle (P = 0.87). Thus, length of the estrous cycle obtained from three-axis accelerometers cannot be used to predict follicle number in crossbred beef heifers; however, machine learning approaches that combine multiple features could be used to integrate parameters of activity with other relevant environmental and management data to quantify AFC and improve reproductive management in beef cows.
PubDate: Tue, 30 Apr 2024 00:00:00 GMT
DOI: 10.1093/tas/txae074
Issue No: Vol. 8 (2024)
- Oxidative stability in meat (pectoralis major) of broiler orally
supplemented with essential oils of allium sativum, Curcuma longa,
Zingiber officinale, and Cinnamomum zeylanicum
First page: txae073
Abstract: AbstractLipid oxidation is a normal process in living muscles, but is escalated postmortem due to the loss of inherent antioxidant defense, which causes quality deterioration of meat. This study investigates the effects of essential oil (EO) supplementation to the drinking water of broiler chicken on physical properties, antioxidants, and lipid oxidation in Pectoralis major during frozen storage. Two hundred day-old chicks of arbo acre were allocated to five groups; control (T1) and the groups supplemented with: Allium sativum (T2), Curcuma longa (T3), Zingiber officinale (T4) and Cinnamomum zeylanicum (T5) at the level of 300ml/L into drinking water throughout a 49-d study. Thereafter, birds were slaughtered and breast meat excised for assessments during a 28-d storage period at 4 °C using standard procedure. The results show that cooking loss of Pectoralis major from T1 birds was not significantly (P > 0.05) different from that of T4, and were significantly higher than those of T2, T3, and T5 birds. Meat from T5 birds showed the lowest drip loss. The results for total antioxidant activity are not similar among sampling days. In general, control group showed inferior values, but T2 and T4 had greater values on days 0 and 28. The rate of lipid peroxidation increased with time; however, EOs administration markedly reduced the peroxidation rates compared to controls. The catalase activity of breast meat was significantly declined from day 14, but was enhanced as an effect of EO consumption especially in group T5 at 21 and 28 d. Supplementation of garlic, turmeric, and cinnamon EOs to broiler chickens increased glutathione peroxidase in breast meat on days 21 and 28, while turmeric EO enhanced superoxide dismutase up to 7 d. In conclusion, EOs are valuable supplements for broiler chickens and potent in enhancing meat quality and prolonging the shelf life.
PubDate: Mon, 29 Apr 2024 00:00:00 GMT
DOI: 10.1093/tas/txae073
Issue No: Vol. 8 (2024)
- The effects of different feeding strategies providing different levels of
vitamin A on animal performance, carcass traits, and the conversion rate
of subcutaneous fat color in cull-cows
First page: txae071
Abstract: AbstractCull cows represent a significant percentage of revenue received from the U.S. beef industry; however, cull cows are heavily price discounted at time of slaughter. This experiment’s objective is to evaluate different feeding strategies and their effects on body condition score, subcutaneous fat color, and carcass yield and quality traits in cull cows. The central hypothesis is feeding a high-energy diet, with low levels of vitamin A, for 56 d will improve animal performance, carcass yield, and quality traits in addition to capturing the point (rate) of the conversion of yellow to white subcutaneous fat. In the present experiment 98 Angus crossbreed cows were utilized. Cows were fed either low vitamin A (LVA) diet consisting of whole shelled corn, soybean hulls, soybean meal, and a mineral-vitamin supplement or high vitamin A (HVA) diet, formulated using whole shelled corn, fescue hay, dry distiller grains with soluble, and a mineral-vitamin supplement for 56 d. During the 56 d feeding period, body weights and condition scores, and subcutaneous adipose samples were collected every 14 d. On day 56, cattle were slaughtered; 48 h postmortem carcass characteristics and objective color scores (subcutaneous adipose tissue) were recorded and a sample of the longissimus dorsi lumborum was collected. Subcutaneous adipose tissue samples were utilized to record subjective color scores and then ground to be analyzed for β-carotene concentration. The longissimus dorsi lumborum samples (2.54 cm slices) were removed for Warner-Bratzler shear force (WBSF) and pH testing. Data were analyzed using the MIXED procedure of SAS. Feeding cull cows LVA resulted in differences in subcutaneous carcass fat color (P = 0.01) as well as b* values (P < 0.01) on day 56 compared with HVA. Subjective fat color scores were not different (P > 0.10) on day 0 or 14 but were different (P ≤ 0.05) on days 28, 42, and 56. Additionally, 9-cis-β-carotene concentration on day 56 were different (P = 0.05) between treatments. A trend was noticed for all-trans-β-carotene concentration (P = 0.10) on day 56 as well. Cull cow body weights were greater (P ≤ 0.04) when fed the LVA diet starting on days 14, 28, and 42; and a trend was noticed on day 56 (P = 0.09). Overall, cows fed the LVA treatment for 56 d exhibited decreased adipose yellowness and β-carotene concentrations as well as increased live weights.
PubDate: Sat, 27 Apr 2024 00:00:00 GMT
DOI: 10.1093/tas/txae071
Issue No: Vol. 8 (2024)
- Supplementing narasin or monensin to control coccidiosis in naturally
infected calves
First page: txae069
Abstract: AbstractThis experiment compared narasin and monensin as anticoccidials for calves naturally infected with Eimeria spp. Twenty-four weaned, non-castrated male calves (Bos indicus × B. taurus cross) were assigned to this experiment (days −8 to 42). All calves were infected by Eimeria spp. according to oocyst count per gram (OPG) from fecal samples collected on days −8 and −7 (average 1,059 ± 101 oocysts/g). Calves were housed in individual pens, received corn silage, mineral mix, and water for ad libitum consumption, in addition to a grain-based supplement at 200 g/head daily. Fecal samples were collected on days −2 and −1 for OPG, and results averaged as initial OPG value. Calves were blocked according to initial OPG into eight blocks of three calves each, ranked within each block according to body weight (BW) recorded on day −1, and assigned to receive narasin (NAR; 0.8 mg/kg of BW), monensin (MON; 1 mg/kg of BW), or no ionophore (CON; negative control). Ionophores were added to the grain-based supplement, and offered from days 0 to 42 of the experiment. Calf BW was recorded on days 7, 14, 21, 28, 35, and 42. Fecal samples were collected on days 6 and 7, 13 and 14, 20 and 21, 26 and 27, 34 and 35, and 41 and 42 for OPG analysis, and results from samples collected on consecutive days were averaged. Aliquoted fecal samples were also pooled across calves from the same treatment and collection days, and used to determine the prevalence of individual species of Eimeria. No treatment effects were detected (P ≥ 0.51) for calf BW or growth rate. A treatment × day interaction was detected (P < 0.01) for OPG, as NAR and MON calves had less (P < 0.01) OPG compared with CON calves beginning on day 7. The OPG was also less (P ≤ 0.03) in MON compared with NAR calves on days 7, 14, and 28, but did not differ (P ≥ 0.48) on days 21, 35, and 42. The anticoccidial efficacy of NAR and MON did not differ (P ≥ 0.16) when calculated across all Eimeria spp., or according to prevalence of E. bovis and E. alabamensins. A treatment × day interaction was detected (P = 0.04) for anticoccidial efficacy to E. alabamensis, which was greater (P < 0.01) in MON calves on days 7 and 14 and did not differ (P ≥ 0.40) afterward. Collectively, both ionophores were similarly effective in controlling coccidiosis upon completion of the 42-d study, although the anticoccidial effects of monensin were noted earlier in the experiment. Nonetheless, these results corroborate narasin as an efficient anticoccidial ionophore for naturally infected calves.
PubDate: Fri, 26 Apr 2024 00:00:00 GMT
DOI: 10.1093/tas/txae069
Issue No: Vol. 8 (2024)
- Breeder age and hatching egg storage duration: effects on post-hatch
performance of FUNAAB- α broiler chickens
First page: txae070
Abstract: AbstractThis trial was designed to evaluate the influence of hatching egg storage length and broiler breeder hens’ age on post-hatch growth performance and physiological responses of FUNAAB-α chickens. Five hundred fertile eggs from each of 60 and 32-wk-old FUNAAB-α breeder hens were collected and assigned to five storage durations (0, 3, 7, 11, and 15 d). The hatching eggs were incubated using the conventional protocol. Data were collected on the growth performance and physiological responses. A 2 × 5 factorial design was used for the experiment. The results revealed that there was a decline in the final body weight in chickens from eggs of 15 and 11 d storage compared to the chickens from 7, 3, and 0 egg storage days. Chickens of 32-week-old breeder hens had higher (P < 0.05) mean corpuscular volume, white blood cell, heterophil, and pack cell volume values compared to 60-week-old breeder hens. Hatchlings from 60-week-old breeders had a higher liver percentage (3.0% yolk-free body weight [YFBW]) than those from 32-week-old breeders (2.8% YFBW). It was concluded that an extended storage duration of 15 d adversely affected the carcass traits and growth performance of chickens from egg storage above seven days.
PubDate: Fri, 26 Apr 2024 00:00:00 GMT
DOI: 10.1093/tas/txae070
Issue No: Vol. 8 (2024)
- Association study between SNP markers located in meat quality candidate
genes with intramuscular fat content in an endangered dual-purpose cattle
population
First page: txae066
Abstract: AbstractThe aim of this study was to associate single nucleotide polymorphisms (SNP) of the bovine calcium-activated neutral protease µ-calpain, calpastatin, diacylglycerol-O-acyltransferase, adipose fatty acid binding protein, retinoic acid receptor-related orphan receptor C (RORC), and thyroglobulin (TG) gene with intramuscular fat content (IMF). Therefore, 542 animals of the cattle breed “Rotes Höhenvieh” (RHV) were phenotyped for IMF. Genotyping of the animals was performed using polymerase chain reaction-restriction fragment length polymorphism tests for six SNP from candidate genes for meat quality traits. In addition, we calculated allele substitution and dominance effects on IMF. A subgroup of animals (n = 44, reduced dataset) with extraordinary high IMF was analyzed separately. The mean IMF content was 2.5% (SD: 2.8) but ranged from 0.02% to 23.9%, underlining the breeds’ potential for quality meat production. Allele and genotype frequencies for all SNP were similar in the complete and reduced dataset. Association analyses in the complete dataset revealed the strongest effects of RORC on IMF (P = 0.075). The log-transformed least-squares mean for IMF of genotype g.3290GG was 0.45 ± 0.16, 0.26 ± 0.14 for genotype g.3290GT, and 0.32 ± 0.14 for genotype g.3290TT. In the reduced dataset, we found a significant effect (P < 0.05) of the g.422C>T-SNP of TG on IMF, with highest IMF for genotype CT (0.91 ± 0.17), lowest IMF for genotype TT (0.37 ± 0.25), and medium IMF for genotype CC (0.59 ± 0.16; log-transformed values). Compared to the complete dataset, allele substitution effects increased in the reduced dataset for most of the SNP, possibly due to the selective genotyping strategy, with focus on animals with highest IMF implying strong phenotypic IMF contrast. Dominance effects were small in both datasets, related to the high heritability of IMF. Results indicated RHV breed particularities regarding the effects of meat quality genes on IMF. An explanation might be the breeding history of RHV with focus on adaptation and resilience in harsh outdoor systems. Consequently, it is imperative to develop breed-specific selection strategies. Allele substitution and dominance effects were in a similar direction in both datasets, suggesting the same breeding approaches for different RHV strains in different regions. Nevertheless, a selective genotyping approach (reduced dataset), contributed to more pronounced genotype effect differences on IMF and dominance values.
PubDate: Tue, 23 Apr 2024 00:00:00 GMT
DOI: 10.1093/tas/txae066
Issue No: Vol. 8 (2024)
- Non-protein nitrogen supplementation on in vitro fermentation profile,
methane production, and microbial nitrogen synthesis in a corn
silage-based substrate
First page: txae065
Abstract: AbstractNon-protein nitrogen (NPN) supplements improve animal performance in backgrounding diets. However, there is scarce information regarding the effect of different NPN sources and combinations on ruminal fermentation profile. The current study aimed to evaluate the effect of different NPN sources and their combinations on in vitro fermentation, microbial N synthesis, and methane (CH4) production in a backgrounding diet. Incubations were conducted on three separate days for 24 h using corn silage and cotton gin byproduct (70% and 30% of DM, respectively) as substrate. Treatments were control (without NPN), urea, and five different proportions of urea–biuret and nitrate (100:0, 75:25, 50:50, 25:75, and 0:100). Each treatment, except control, was formulated to be isonitrogenous and equivalent to 1% urea inclusion. Ruminal fluid was collected from two ruminally cannulated Angus crossbred steers fed ad libitum corn silage and cotton gin byproduct plus 100 g of a urea–biuret–nitrate mixture. The concentration of volatile fatty acids (VFAs) and ammonia nitrogen (NH3-N) were determined at 12 and 24 h of incubation. Final pH, in vitro dry and organic matter digestibility, total gas production, and concentration of CH4 were determined at 24 h. The supplementation of NPN increased (P < 0.05) the concentration of NH3-N at 12 and 24 h. Although NPN supplementation increased (P < 0.05) the concentration of total VFA and acetate at 12 h, treatments did not differ (P > 0.05) at 24 h. Supplementation of NPN increased (P < 0.05) the proportion of acetate at 12 and 24 h but tended to reduce (P = 0.054) the proportion of propionate only at 12 h. Digestibility and pH were not different (P > 0.05) among treatments. Increasing nitrates in the NPN supplement increased (P < 0.05) the proportion of acetate and reduced (P < 0.05) the proportion of butyrate at 12 and 24 h. The supplementation of NPN increased (P < 0.05) microbial N synthesis. Furthermore, increasing nitrate proportion in the NPN supplement increased (P < 0.05) the microbial N synthesis and efficiency of N use. Supplementation of NPN did not modify (P > 0.05) total gas or CH4 production. However, increasing nitrate proportion in the NPN supplement linearly reduced (P < 0.05) CH4 production. Supplementation of NPN increased NH3-N concentration and microbial N while increasing the inclusion of nitrate decreased the production of CH4 and increased the microbial N synthesis in a corn silage-based substrate under in vitro conditions.
PubDate: Tue, 23 Apr 2024 00:00:00 GMT
DOI: 10.1093/tas/txae065
Issue No: Vol. 8 (2024)
- Economic assessment of using Bermudagrass stockpiling and annual cereal
pasture to extend grazing in cow-calf operations
First page: txae067
Abstract: AbstractBermudagrass (Cynodon dactylon L.) stockpiling and cool-season annual pastures can extend grazing seasons in cow-calf operations and reduce winter feeding costs, but less is known about how these practices interact and their effect on producer profitability. Data from a completely randomized-design experiment in South-Central Oklahoma were collected on three grazing systems for cows and calves: bermudagrass pasture (CONTROL), stockpiled bermudagrass and interseeded cool-season pasture (SPINT), and stockpiled bermudagrass plus cropland no-till seeded with a summer cover-crop followed by cool-season annuals (SPCROP). A mixed model was used to estimate the effects of grazing system on weaning weights, total hay, and total range cubes (crude protein [CP] = 30%) fed in each system. Enterprise budgeting was used to calculate the expected net return of each system. Weaning weight did not vary between systems (P = 0.6940), resulting in similar revenues. Relative to other treatments, the quantity of cubes fed in the CONTROL system were significantly higher (P < 0.0001) while hay fed was significantly higher in the SPCROP system (P = 0.0036). Increased machinery costs, seed costs, and fertilization requirements in bermudagrass stockpiling, interseeding, and cropland production outweighed the cost savings associated with less feeding. Total costs were $446 ha−1 ($722 hd−1), $451 ha−1 ($732 hd−1), and $553 ha−1 ($895 ha−1) for the CONTROL, SPINT, and SPCROP systems, respectively. Overall, the CONTROL system was $3.13 ha−1 ($5.08 hd−1) and $98.91 ha−1 ($160.10 hd−1) more profitable than the SPINT and SPCROP systems.
PubDate: Mon, 22 Apr 2024 00:00:00 GMT
DOI: 10.1093/tas/txae067
Issue No: Vol. 8 (2024)
- A review of soybean processing byproducts and their use in swine and
poultry diets
First page: txae063
Abstract: AbstractDue to its importance in animal feed, soybean meal has been extensively studied to optimize its use in livestock diets. Despite extensive research, the industry has not fully characterized specific areas of soybean processing such as the inclusion of soybean byproducts added back to soybean meal during processing. Soybean processing byproducts can encompass a large variety of materials including weeds and foreign material, soybean hulls, gums, soapstocks, lecithins, spent bleaching clays, and deodorizer distillates. Despite the potential for being added back to soybean meal when a crushing plant is integrated with an oil refinery, there is currently limited information on the composition of many of these soybean processing byproducts and their subsequent effects on soybean meal quality and animal performance. Therefore, there may be opportunities for a new area of research focused on soybean processing byproducts and their optimal use within the livestock feed industry. This review summarizes the current information on soybean byproducts with a focus on identifying the areas with the greatest potential for future research in swine and poultry nutrition.
PubDate: Sat, 13 Apr 2024 00:00:00 GMT
DOI: 10.1093/tas/txae063
Issue No: Vol. 8 (2024)
- Bacillus paralicheniformis 809 and Bacillus subtilis 810 support in vitro
intestinal integrity under hydrogen peroxide and deoxynivalenol challenges
First page: txae061
Abstract: AbstractWe designed and conducted two in vitro experiments to evaluate the effects of two Bacillus spp. probiotics on gut barrier integrity using the transepithelial electrical resistance (TEER) assay under two different challenge models. In Exp. 1, intestinal epithelial cells received or not (CON) B. paralicheniformis 809 (BLI) or B. subtilis 810 (BSU) at a rate of 1 × 108 colony forming units (CFU)/transwell. Two hours after treatment application (CON, BLI, or BSU), 5 mM of the reactive oxygen species hydrogen peroxide, mimicking mucosal oxidative stress, was added alone (HYP) or with each of the Bacillus spp. (HYP + BLI or HYP + BSU). In Exp. 2, cells were assigned to the same treatments as in Exp. 1 (CON, BLI, and BSU), or mycotoxin deoxynivalenol (DON), which was added alone or in combination with BLI or BSU, resulting in another two treatments (DON + BLI and DON + BSU). Transepithelial electrical resistance was measured for 14 h postchallenge. In Exp. 1, a treatment × hour interaction was observed for TEER (P < 0.0001). Adding BLI and BSU resulted in greater TEER values vs. CON for most of the experimental period (P < 0.02), whereas HYP reduced mean TEER and area under the curve (AUC), while increasing the amount of sugar that translocated through the monolayer cells (P < 0.001). A treatment × hour interaction was also observed in Exp. 2 (P < 0.0001), as DON led to an immediate and acute drop in TEER that lasted until the end of the experimental period (P < 0.0001). Both BLI and BSU alleviated the DON-induced damaging effects on the integrity of intestinal epithelial cells, whereas both Bacillus spp. alleviated the damage caused by DON alone and the proportion of sugar that translocated through the monolayer cells was not different between CON and DON + BLI (P = 0.14) and DON + BLI and DON + BSU (P = 0.62). In summary, both Bacillus spp. strains (B. paralicheniformis 809 and B. subtilis 810) were able to counteract the damaging effects of the challenge agents, hydrogen peroxide and deoxynivalenol, on gut barrier integrity.
PubDate: Sat, 13 Apr 2024 00:00:00 GMT
DOI: 10.1093/tas/txae061
Issue No: Vol. 8 (2024)
- Predicting fat cover in beef cattle to make on-farm management decisions:
a review of assessing fat and of modeling fat deposition
First page: txae058
Abstract: AbstractDemands of domestic and foreign market specifications of carcass weight and fat cover, of beef cattle, have led to the development of cattle growth models that predict fat cover to assist on-farm managers make management decisions. The objectives of this paper are 4-fold: 1) conduct a brief review of the biological basis of adipose tissue accretion, 2) briefly review live and carcass assessments of beef cattle, and carcass grading systems used to develop quantitative compositional and quality indices, 3) review fat deposition models: Davis growth model (DGM), French National Institute for Agricultural Research growth model (IGM), Cornell Value Discovery System (CVDS), and BeefSpecs drafting tool (BeefSpecsDT), and 4) appraise the process of translating science and practical skills into research/decision support tools that assist the Beef industry improve profitability. The r2 for live and carcass animal assessments, using several techniques across a range of species and traits, ranged from 0.61 to 0.99 and from 0.52 to 0.99, respectively. Model evaluations of DGM and IGM were conducted using Salers heifers (n = 24) and Angus-Hereford steers (n = 15) from an existing publication and model evaluations of CVDS and BeefSpecsDT were conducted using Angus steers (n = 33) from a research trial where steers were grain finished for 101 d in a commercial feedlot. Evaluating the observed and predicted fat mass (FM) is the focus of this review. The FM mean bias for Salers heifers were 7.5 and 1.3 kg and the root mean square error of prediction (RMSEP) were 31.2 and 27.8 kg and for Angus-Hereford steers the mean bias were −4.0 and −10.5 kg and the RMSEP were 9.14 and 21.5 kg for DGM and IGM, respectively. The FM mean bias for Angus steers were −5.61 and −2.93 kg and the RMSEP were 12.3 and 13.4 kg for CVDS and BeefSpecsDT, respectively. The decomposition for bias, slope, and deviance were 21%, 12%, and 68% and 5%, 4%, and 91% for CVDS and BeefSpecsDT, respectively. The modeling efficiencies were 0.38 and 0.27 and the models were within a 20 kg level of tolerance 91% and 88% for CVDS and BeefSpecsDT, respectively. Fat deposition models reported in this review have the potential to assist the beef industry make on-farm management decisions on live cattle before slaughter and improve profitability. Modelers need to continually assess and improve their models but with a caveat of 1) striving to minimize inputs, and 2) choosing on-farm inputs that are readily available.
PubDate: Thu, 11 Apr 2024 00:00:00 GMT
DOI: 10.1093/tas/txae058
Issue No: Vol. 8 (2024)
- Chemical composition and digestible and metabolizable energy contents in
cold-pressed canola expellers fed to growing pigs
First page: txae060
Abstract: AbstractCold-pressed canola expellers (CPCE) are a byproduct of canola oil production obtained using the pressing method without thermal and chemical treatment. While CPCE is a valuable source of dietary energy and protein in swine nutrition, the discrepancy in processing conditions leads to variability in the nutritional quality of CPCE from different sources. This study aimed to determine the chemical composition, and digestible energy (DE) and metabolizable energy (ME) values of CPCE when fed to growing pigs. Samples of CPCE were collected from five processing facilities across Western Canada. The physical appearance of the CPCE samples hinted at a potential quality variation. Samples were subjected to a complete chemical characterization. Variations (P < 0.05) were observed in the chemical composition, with the exception of non-phytate phosphorus, xylose, mannose, and galactose. On a g/kg dry matter (DM) basis, CPCE samples ranged as follows: ether extract from 85 to 177; crude protein (CP) from 351 to 419; neutral detergent fiber 231 to 300; total dietary fiber from 326 to 373; glycoproteins from 30 to 76; non-starch polysaccharides from 188 to 204, non-phytate phosphorus from 5.5 to 6.4, and gross energy (GE) in kcal/kg 5,027 to 5,635. The total glucosinolates (GLS) ranged from 5.0 to 9.7 µmol/g DM. Thirty-six (36) growing barrows, with an average initial body weight of 19.2 ± 1.0 kg, were individually housed in metabolism crates and assigned to one of the six experimental diets in a completely randomized design, with six pigs per diet. The diets included a corn–soybean meal (SBM)-based basal diet (100%) and five (5) experimental diets in which 18% of the basal diet was substituted with CPCE from different producers. Pigs were fed the experimental diets for 10 d, with 5-d adaptation period, followed by a 5-d period for the total, but separate, collection of feces and urine. Significant differences (P < 0.05) among processing plants were observed in the DE and ME contents of CPCE, which averaged 3,531 and 3,172 kcal/kg DM, respectively. Differences (P < 0.05) were noted in the apparent total tract digestibility of GE, nitrogen (N), as well as in the retention of DM, GE, and N in CPCE samples. In conclusion, while the chemical composition and values of DE and ME in CPCE vary among processors, the byproduct obtained through cold pressing process can be a valuable source of energy and protein for pig nutrition.
PubDate: Thu, 11 Apr 2024 00:00:00 GMT
DOI: 10.1093/tas/txae060
Issue No: Vol. 8 (2024)
- Production and use of dry-rolled hybrid rye grain as a replacement for
barley grain on growth performance and carcass quality of feedlot steers
First page: txae059
Abstract: AbstractThe objectives were to compare cereal grain and straw yield between barley and hybrid rye (HR) and to evaluate whether the inclusion of dry-rolled HR grain as a replacement for barley grain affected feed intake and growth for growing cattle, and feed intake, growth, and carcass characteristics for finishing cattle. Crop yield was measured by directly weighing harvested grain and straw bales (n = 3 plots/grain type). Three-hundred sixty steers with an initial body weight (BW) of 348 ± 40 kg were stratified by BW and randomly assigned to 1 of the 24 pens during the growing phase (n = 8; 65 d). The control diet (BCON) included 60.22% barley grain with HR included by replacing 50 (BMID) or 100% (BHIGH) of the barley grain on a dry matter (DM) basis. Steers were re-randomized for the finishing phase (n = 6; 118 d) and treatments included a control diet containing 88.60% barley grain (FCON) with HR replacing 33 (FLOW), 67 (FMED), or 100% (FHIGH) of the barley grain (DM basis). The grain yield was greater (P = 0.04) and straw yield tended (P = 0.06) to be less for HR than barley. There were no effects of HR inclusion on DM intake (DMI) or G:F during the growing phase, but average daily gain (ADG) responded quadratically (P = 0.02) with cattle fed 50% HR having the greatest gain. During finishing, DMI decreased linearly as HR grain inclusion increased (P < 0.01). ADG initially increased from FCON to FLOW followed by a decrease with increasing HR inclusion (quadratic, P < 0.01), but G:F was not affected. Hot carcass weight was greatest for FCON with the magnitude of difference between FCON and the HR treatments increasing with increasing inclusion of HR (quadratic, P = 0.02). There was a linear increase in dressing percentage (P = 0.02) and a linear reduction in back fat thickness (P = 0.04) with increasing inclusion of HR. Increasing the inclusion of HR during finishing cubically (P < 0.01) affected the proportion of minor and severe liver abscesses with an average of 34.60% severely abscessed livers when HR was included compared to 11.11% for BCON. HR may have greater grain yield than barley, and partial replacement of barley grain with HR may improve ADG without affecting DMI or G:F during the growing phase. However, replacing barley grain in finishing diets with HR decreases DMI, and increases the risk of minor and severe liver abscesses, but does not affect feed conversion, suggesting HR should not replace more than 33% of the barley grain to maintain ADG.
PubDate: Thu, 11 Apr 2024 00:00:00 GMT
DOI: 10.1093/tas/txae059
Issue No: Vol. 8 (2024)
- Burlap and buddies: the effects of social enrichment (preweaning mixing)
and object enrichment (burlap) on piglet behavior and welfare in the
postweaning environment
First page: txae057
Abstract: AbstractThe process of weaning piglets in commercial swine operations subjects them to numerous abrupt and stressful changes often resulting in negative welfare consequences. The objective was to study the postweaning effects of early-life (1 to 3 d of age) preweaning socialization in multi-litter groups as well as object enrichment (burlap sheet) in the pre- and postweaning environment by comparing six treatments that combined mixing of one vs. two vs. four litters mixed preweaning with and without burlap provision. An ANOVA linear model was run on all normal data, expressed per experimental unit (and behavior data were averaged over time), while non-normal data were analyzed using the Kruskal–Wallis test. Non-enriched groups of piglets were observed manipulating pen objects more often than the enriched groups (P = 0.005). Biting behaviors, including the chewing of ears and tails of pen-mates but excluding fighting, were observed the least in groups of pigs of four litters mixed preweaning, while piglets that were not mixed preweaning were observed biting the most (P = 0.03). Piglets who were not mixed preweaning also manipulated the burlap more frequently than the piglets from groups of 4 litters mixed preweaning (P = 0.02). Biting (P < 0.001) and displacements (P = 0.03) and fighting (P = 0.002) throughout the pen were observed less in the enriched groups. There were fewer lesions per pig in the enriched groups vs. non-enriched groups initially (P = 0.07) and 1 wk after weaning (P = 0.10). Furthermore, pigs mixed in groups of four litters preweaning also tended to have lower lesion scores (P = 0.07) 1-wk postweaning compared to the other treatments. However, there were no differences between treatments in the proportion of piglets resting, eating/drinking, being active, or using the burlap, or for the observed frequency of displacements at the feeder, social behaviors, or belly nosing (P > 0.10). Overall, social enrichment encourages socialization with unfamiliar conspecifics at a younger age while object enrichment allows pigs to redirect their attention toward objects such as burlap. Both may improve pig behavior and welfare after weaning.
PubDate: Tue, 09 Apr 2024 00:00:00 GMT
DOI: 10.1093/tas/txae057
Issue No: Vol. 8 (2024)
- Burlap and buddies: the effects of social enrichment (preweaning mixing)
and object enrichment (burlap) on piglet performance, behavior, and
welfare in the preweaning environment
First page: txae053
Abstract: AbstractWhen weaned in commercial operations, piglets are not only separated from their sow but also mixed with unfamiliar pigs in an unfamiliar environment with a new diet. These abrupt changes can be stressful for piglets, often having negative welfare consequences. Our objective was to study the effects of early-life preweaning socialization and object enrichment in the preweaning environment. We compared piglet performance, behavior, and welfare across six treatments that combined multi-litter group size (1 vs. 2 vs. 4 litters) and burlap (yes vs. no). We recorded piglet behavior and lesion-scored sows and piglets. Normal conforming data, expressed per experimental unit (and behavior data were averaged over time), were analyzed by ANOVA. When given the opportunity in the sow barn, piglets in multi-litter groups socialized with other litters. Burlap use (P = 0.08) was observed in < 5% of the observations but tended to increase in mixed litter groups. Cross-sucking was observed in ~12% of the observations within mixed litter groups and tended to increase with mixed group size (P = 0.08). While there was no difference in the proportion of piglets nursing (P > 0.10), piglets were less active in the single crate groups and most active in the groups of two litters mixed (P = 0.03). Additionally, observed piglet/sow biting behaviors did not differ between treatments; however, piglet-piglet biting (P = 0.07), and pen object manipulation (P = 0.07) tended to be observed more frequently in non-enriched groups. Piglet displacements were observed more often in non-enriched groups around the pen (P = 0.03) but tended to be observed more often in enriched groups at the teat (P = 0.07). Preweaning socialization and object enrichment had no impact on the average number of piglets weaned per sow or total piglet mortality (P > 0.10). However, the proportion of laid-on piglets decreased as the number of mixed litters increased (P = 0.02). The average number of lesions per piglet did not differ between treatments. Although the final lesion scores of sow teat and udder condition did not differ between treatments (P > 0.10), sow udder scores tended to worsen more in the single litters than in the mixed litters (P = 0.08). Overall, social and object enrichment allows piglets to socialize at a younger age and to redirect their attention toward an object (burlap) which does not negatively impact piglet or sow performance, or behavior, and may improve piglet welfare around weaning.
PubDate: Tue, 09 Apr 2024 00:00:00 GMT
DOI: 10.1093/tas/txae053
Issue No: Vol. 8 (2024)
- Effects of poor maternal diet during gestation are detected in F2
offspring
First page: txae055
Abstract: AbstractPoor maternal nutrition of F0 ewes impairs F1 offspring growth, with minimal differences in glucose tolerance or select metabolic circulating factors, and independent of differences in residual feed intake (RFI). To determine if poor maternal nutrition in F0 ewes alters F2 offspring growth, circulating leptin, feed efficiency, or glucose tolerance, F0 ewes (n = 46) pregnant with twins were fed 100% (control), 60% (restricted), or 140% (over) of National Research Council requirements from days 30 ± 0.02 of gestation until parturition. At 16 to 19 mo of age, female F1 (n = 36) offspring were bred to generate F2 offspring [CON-F2 (n = 12 ewes; 6 rams), RES-F2 (n = 7 ewes; 13 rams), or OVER-F2 (n = 13 ewes; 9 rams) corresponding to diets of the granddam (F0)]. Lamb body weights (BW) and blood samples were collected weekly from days 0 to 28 and every 14 d until day 252 of age. Circulating leptin was measured in serum at days 0, 7, 14, 56, 210, and 252. An intravenous glucose tolerance test was performed at days 133 ± 0.28. At days 167 ± 0.33, individual daily intake was recorded over a 77-d feeding period to determine RFI. Rams were euthanized at days 285 ± 0.93, and body morphometrics, loin eye area (LEA), back fat thickness, and organ weights were collected and bone mineral density (BMD) and length were determined in the right hind leg. During gestation, OVER-F1 ewes tended to be 8.6% smaller than CON-F1 ewes (P ≤ 0.06). F2 offspring were of similar BW from birth to day 70 (P ≥ 0.20). However, from days 84 to 252, RES-F2 offspring tended to be 7.3% smaller than CON-F2 (P ≤ 0.10). Granddam diet did not influence F2 ram body morphometrics, organ or muscle weights, LEA, adipose deposition, or leg BMD (P ≥ 0.84). RES-F2 (−0.20) and CON-F2 (−0.45) rams tended to be more feed efficient than CON-F2 ewes (0.31; P ≤ 0.08). No effects of granddam diet were observed on glucose or insulin average or baseline concentrations, area under the curve, first-phase response, or ratio (P ≥ 0.52). However, CON-F2 rams (297 mg/dL ± 16.5) had a greater glucose peak compared with RES-F2 rams (239 mg/dL ± 11.2; P = 0.05). Peak insulin concentrations were not influenced by granddam diet (P = 0.75). At d 56, RES-F2 and OVER-F2 offspring had 53.5% and 61.8% less leptin compared with CON-F2 offspring, respectively (P ≤ 0.02). These data indicate that poor maternal nutrition impacts offspring growth into the second generation with minimal impacts on offspring RFI, glucose tolerance, and circulating leptin.
PubDate: Tue, 09 Apr 2024 00:00:00 GMT
DOI: 10.1093/tas/txae055
Issue No: Vol. 8 (2024)
- Determination of gas flux and animal performance test duration of growing
cattle in confined conditions
First page: txae056
Abstract: AbstractData from three experiments was analyzed to determine the number of visits and days to assess gas flux (CH4, CO2, and O2), dry matter intake (DMI), and average daily gain (ADG) from growing animals under confined conditions. In experiment 1, 213 animals (461 ± 91 kg initial body weight [BW]) were fed a backgrounding diet and evaluated for 60 d. In experiment 2, 169 steers (488 ± 37 kg initial BW) were fed a finishing diet and assessed for 70 d. In experiment 3, 64 steers (514 ± 42 kg initial BW) were fed a finishing diet and evaluated for 80 d. In each experiment, animals were placed in one pen with one Greenfeed and five SmartFeeds to collect gas flux and feed intake simultaneously. Gas flux was analyzed using data from 161 animals from the three experiments with 100 visits for 2 or more min or 3 or more min. Also, metabolic heat production (MHP) was estimated using the individual gas flux. Daily DMI was calculated as the daily feed intake corrected by the dry matter concentration. ADG was computed as the slope of the regression of the shrunk BW (96% BW) throughout each of the experimental periods. The mean gas flux and MHP were estimated for increasing or decreasing 5-visit intervals starting with the first or the last 5 visits and increasing or decreasing until the full 100-visit dataset was utilized, respectively. Intervals of DMI were estimated for increasing or decreasing 5-d intervals starting with the first or the last 5 d and increasing or decreasing until the end of the experimental period, respectively. Intervals of ADG were estimated for increasing or decreasing measurement period intervals until the end of the experimental period, respectively. Pearson and Spearman correlations were computed between the maximum visits or days and each shortened visit or day interval. The minimum number of visits and days was determined when correlations with the total visits were greater than 0.95. The results indicated that the minimum number of visits needed to quantify CO2, O2, and MHP accurately was 40, while CH4 was 60. A visitation length of 2 min or more or 3 min or more did not modify the gas flux determination. Thus, based on the average daily visitation in these experiments, gas flux data could be collected for 25 d. Additionally, the required days to determine DMI was 30, while ADG could not be assessed in a shorter than 60-d period.
PubDate: Mon, 08 Apr 2024 00:00:00 GMT
DOI: 10.1093/tas/txae056
Issue No: Vol. 8 (2024)
- Effects of Bacillus subtilis on in vitro ruminal fermentation and methane
production
First page: txae054
Abstract: AbstractThe objective of this study was to evaluate the effect of a proprietary strain of a Bacillus subtilis on in vitro ruminal fermentation and methane production in batch culture serum bottles. One hundred forty-nine batch culture bottles were used in a complete randomized block design. The arrangement of treatments was a 3 × 3 × 4 factorial to evaluate the effects of inoculum, time, diet, and their respective interactions. There were three experimental runs total, where the run was used as block. Inoculum treatments were 1.85 mg/mL of microcrystalline cellulose (CON); 10 billion B. subtilis plus microcrystalline cellulose (A1); and 60 billion B. subtilis plus microcrystalline cellulose (A2). Diet treatments were 0.50 g of early lactation diet (E, 30% starch), mid-lactation diet (M, 25% starch), or dry cow diet (D, 18% starch). The combination resulted in total of nine treatments. Each treatment had five replicates, two of which were used to determine nutrient degradability at 24 and 48 h after inoculation, and three were used to determine pH, ammonia nitrogen (NH3-N), volatile fatty acids, lactate, total gas, and methane production at 3, 6, 24, and 48 h after inoculation. Fixed effects of inoculum, diet, and their interaction were tested using the GLIMMIX procedure of SAS. Significance was declared at P ≤ 0.05. We observed that, compared to control, the supplementation of B. subtilis, decreased the production of acetate and propionate, while increasing the production of butyrate, iso-butyrate, valerate, iso-valerate, and caproate within each respective diet. Additionally, the total methane production exhibited mixed responses depending on the diet type. Overall, the inclusion of B. subtilis under in vitro conditions shows the potential to reduce ruminal methane production when supplemented with a mid-lactation diet, constituting a possible methane mitigation additive for dairy cattle diets.
PubDate: Mon, 08 Apr 2024 00:00:00 GMT
DOI: 10.1093/tas/txae054
Issue No: Vol. 8 (2024)
- Online feeding behavior monitoring of individual group-housed grow-finish
pigs using a low-frequency RFID electronic feeding system
First page: txae051
Abstract: AbstractEarly identification of animals in need of management intervention is critical to maximize animal health and welfare and minimize issues with productivity. Feeding behavior, captured by automated feeding systems, can be used to monitor the health and welfare status of individual pigs. Here, we present a framework for monitoring feeding behavior of grow-finish pigs in real time, using a low-frequency radio frequency identification (RFID) system. Using historical data, an autoregressive linear model for predicting daily time at the feeder was developed and utilized to detect anomalous decreases in feeding behavior associated with health status of the pig. A total of 2,826 pigs were individually monitored with our warning system over the entire grow-finish period, and health warnings were compared to caretaker diagnoses. The system detected 55.7% of the caretaker diagnoses, and on average these events were detected 2.8 d earlier than diagnosis by the caretaker. High numbers of potentially spurious health warnings, generated by the system, can be partly explained by the lack of a reliable and repeatable gold standard reference data set. Results from this work provide a solid basis for monitoring individual animals, but further improvements to the system are necessary for practical implementation.
PubDate: Sat, 06 Apr 2024 00:00:00 GMT
DOI: 10.1093/tas/txae051
Issue No: Vol. 8 (2024)
- First evaluation of the impact of a targeted subunit vaccine against
bovine viral diarrhea virus in feedlot cattle
First page: txae046
Abstract: AbstractBovine respiratory disease (BRD) is a serious health and economic problem in the beef industry, which is often associated with transportation and caused by different pathogens. In this study, we evaluated the effect of a novel subunit targeted vaccine against bovine viral diarrhea virus (BVDV) in feedlot cattle, a major viral agent of BRD. The core of this novel vaccine is the fusion of the BVDV structural glycoprotein, E2, to a single-chain antibody, APCH, together termed, APCH-E2. The APCH antibody targets the E2 antigen to the major histocompatibility type II molecule (MHC-II) present in antigen-presenting cells. To evaluate the vaccine, 2,992 animals were randomly allocated into two groups, control group (N = 1,491) and treatment group (N = 1,501). Animals of both groups received the routine sanitary plan: two doses of clostridial, respiratory, and rabies vaccines. Animals within the treatment group also received two doses of a targeted subunit vaccine against BVDV. Serum samples were taken on the day of the first inoculation (T0) and 90 d later (T90). Viral circulation was monitored using an anti-P80 ELISA (virus-specific) and immune response was evaluated by anti-E2 ELISA (detects virus and vaccine immune responses). Only animals treated for respiratory disease were considered positive cases of BRD. Results demonstrate that the control group had significantly more animals treated for BRD cases compared to the treatment group (5.9% vs. 3.7%, P = 0.02). The control group had a greater number of animals positive for anti-P80 antibodies and significantly fewer animals positive for anti-E2 antibodies compared to the treatment group (69% vs. 61% and 71% vs. 99%, respectively, P = 0.003), consistent with natural viral circulation within this group. The treatment group, conversely, had fewer animals positive for anti-P80 antibodies and a greater number of animals positive for anti-E2 antibodies, consistent with a robust vaccine-induced antibody response and a reduction of the BVDV circulation within this group. The data indicate the new subunit targeted vaccine induced greater anti-E2 antibodies and reduced the amount of BVD virus circulation within the treatment group leading to a fewer number of animals needing to be treated for BRD.
PubDate: Sat, 06 Apr 2024 00:00:00 GMT
DOI: 10.1093/tas/txae046
Issue No: Vol. 8 (2024)
- Evaluation of ATP bioluminescence for rapid determination of cleanliness
of livestock trailers after a commercial wash
First page: txae052
Abstract: AbstractPathogens such as porcine epidemic diarrhea virus (PEDV), porcine reproductive and respiratory syndrome (PRRSV), and E. coli are known to spread by contaminated vehicles and equipment. Pork producers have adopted trailer wash policies where each trailer is washed, disinfected, and dried before it can return to a farm. Cleanliness of livestock trailers after washing is determined by visual inspection rather than any objective method. Adenosine triphosphate (ATP) bioluminescence is used in many industries to provide real-time feedback on surface cleanliness through the detection of ATP from organic sources. That same technology may provide trailer wash facilities a way of objectively characterizing a livestock trailer’s suitability to return to a farm after washing. Two ATP luminometers (3M Clean-Trace and Neogen AccuPoint) were used to estimate the correlation between ATP bioluminescence readings and aerobic bacterial plate counts (APCs) from sampled surfaces and to determine locations within a livestock trailer that can accurately estimate surface cleanliness. Five locations in livestock trailers were evaluated. Those locations included the nose access door (NAD), back door flush gate, rear side access door (RSAD), belly flush gate (BFG), and belly side access door (BSAD). There was a positive log–log association between the two luminometers (r = 0.59, P < 0.01). Every log unit increase in one unit, resulted in a 0.42 log increase (P < 0.01) in the other unit. ATP can come from bacteria, yeasts, molds, and manure. There was a poor association (r ≥ 0.10, P ≥ 0.02) between APCs and the ATP luminometers. Still, an increase in relative light units (RLUs) resulted in a corresponding increase in colony-forming units. The greatest area of surface contamination measured by APC was the NAD. RLUs were also greater in the NAD compared to the RSAD, the BFG, and the BSAD (P ≤ 0.01). Because APCs and luminometer RLUs provided similar outcomes, statistical process control charts were developed to determine control limits for RLUs. This provides real-time feedback to trailer wash workers in determining cleanliness outcomes for livestock trailers. These data suggest that ATP bioluminescence can be a reliable method to monitor cleaning effectiveness in livestock trailers. Bioluminescence is a monitoring tool that should be used in conjunction with microbial methods to monitor procedures for cleaning and disinfection.
PubDate: Fri, 05 Apr 2024 00:00:00 GMT
DOI: 10.1093/tas/txae052
Issue No: Vol. 8 (2024)
- Evaluating the effects of benzoic acid on nursery and finishing pig growth
performance
First page: txae049
Abstract: AbstractThree studies were conducted evaluating the use of benzoic acid in swine diets. In experiment 1, 350 weanling barrows (DNA 200 × 400; initially 5.9 ± 0.04 kg) were allotted to one of the five dietary treatments with 14 pens per treatment. Diets were fed in three phases: phase 1 from weaning to day 10, phase 2 from days 10 to 18, and phase 3 from days 18 to 38. Treatment 1 contained no benzoic acid throughout all three phases (weaning to day 42). Treatment 2 included 0.50% benzoic acid throughout all three phases. Treatment 3 contained 0.50% benzoic acid in phases 1 and 2, and 0.25% benzoic acid in phase 3. Treatment 4 contained 0.50% benzoic acid in phases 1 and 2, and no benzoic acid in phase 3. Treatment 5 contained 0.50% benzoic acid in phase 1, 0.25% benzoic acid in phase 2, and no benzoic acid in phase 3. For the overall period, pigs fed 0.50% in the first two phases and 0.25% benzoic acid in the final phase had greater (P < 0.05) average daily gain (average daily gain) than pigs fed no benzoic acid through all three phases, or pigs fed 0.50% in the first two phases and no benzoic acid in the final phase, with pigs fed the other treatments intermediate. Pigs fed 0.50% in the first two phases and 0.25% benzoic acid in the final phase had improved (P < 0.05) gain-to-feed ratio (G:F) compared with pigs fed no benzoic acid throughout all three phases, pigs fed 0.50% in the first two phases and no benzoic acid in the third phase, or pigs fed 0.50%, 0.25%, and no benzoic acid, respectively. For experiment 2, a 101-d trial was conducted using two groups of 1,053 finishing pigs (2,106 total pigs; PIC 337 × 1,050; initially 33.3 ± 1.9 kg). Dietary treatments were corn–soybean meal-dried distillers grains with solubles-based with the addition of none, 0.25%, or 0.50% benzoic acid. Overall, pigs fed increasing benzoic acid had a tendency for increased average daily feed intake (linear, P = 0.083) but decreased G:F (linear, P < 0.05). In experiment 3, 2,162 finishing pigs (DNA 600 × PIC 1050; initially 31.4 ± 2.2 kg) were used in a 109-d trial. Dietary treatments were formulated with or without 0.25% benzoic acid. For the overall experimental period, pigs fed benzoic acid had increased (P < 0.05) G:F. In summary, feeding benzoic acid elicits improved growth performance when fed throughout the entire nursery period while improved G:F in growing-finishing pigs was observed in one experiment, but not in the other.
PubDate: Thu, 04 Apr 2024 00:00:00 GMT
DOI: 10.1093/tas/txae049
Issue No: Vol. 8 (2024)
- Functional evaluation of Bacillus licheniformis PF9 for its potential in
controlling enterotoxigenic Escherichia coli in weaned piglets
First page: txae050
Abstract: AbstractDuring the bacterial selection, isolate PF9 demonstrated tolerance to low pH and high bile salt and an ability to extend the lifespan of Caenorhabditis elegans infected with enterotoxigenic Escherichia coli (ETEC; P < 0.05). Thirty-two weaned piglets susceptible to ETEC F4 were randomly allocated to four treatments as follows: 1) non-challenged negative control group (NNC; basal diet and piglets gavaged with phosphate-buffered saline), 2) negative control group (NC; basal diet and piglets challenged with ETEC F4, 3 × 107 CFU per pig), 3) positive control (PC; basal diet + 80 mg·kg−1 of avilamycin and piglets challenged with ETEC F4), and 4) probiotic candidate (PF9; control basal diet + 2.5 × 109 CFU·kg−1 diet of B. licheniformis PF9 and piglets challenged with ETEC F4). The infection of ETEC F4 decreased average daily gain and gain:feed in the NC group when compared to the NNC group (P < 0.05). The inoculation of ETEC F4 induced severe diarrhea at 3 h postinoculum (hpi), 36, 40 hpi in the NC group when compared to the NNC group (P < 0.05). The supplementation of B. licheniformis PF9 significantly relieved diarrhea severity at 3 hpi when compared to the NC group (P < 0.05). The inoculation of ETEC F4 reduced duodenal, jejunal, and ileal villus height (VH) in the NC group when compared to the NNC group. A significant (P < 0.05) decrease was detected in the duodenal VH in the PC and NNC groups. Moreover, the NNC group had a reduced relative mRNA level of Na+-glucose cotransporter 1 (SGLT1) when compared to the NC group (P < 0.05). Compared to the NC and NNC groups, the supplementation of B. licheniformis PF9 increased the relative mRNA levels of aminopeptidase N, occludin, zonula occludens-1, and SGLT1 (P < 0.05). The supplementation of B. licheniformis PF9 also significantly increased the relative mRNA level of excitatory amino acid transporter 1 when compared to the NC group (P < 0.05). Piglets supplemented with B. licheniformis PF9 showed lower relative abundance of Bacteroidetes in the colon than piglets from the NNC group (P < 0.05). The NNC group had a higher relative abundance of Firmicutes in the ileum than all the challenged piglets (P < 0.05); however, a lower relative abundance of Proteobacteria in the ileum and colon was observed in the NC group (P < 0.05). This study provides evidence that B. licheniformis PF9 has the potential to improve the gut health of piglets under challenging conditions.
PubDate: Wed, 03 Apr 2024 00:00:00 GMT
DOI: 10.1093/tas/txae050
Issue No: Vol. 8 (2024)
- Effect of chronic cyclic heat stress and supplemented inorganic and
organic zinc source levels on grow-finish pig growth performance and
estimated body composition
First page: txae029
Abstract: AbstractZinc (Zn) supplementation has proved to mitigate the effects of heat stress with varying effects evident with Zn source during acute heat events. However, the effects of Zn supplementation during long-term summer weather patterns have yet to be explored. Therefore, the objective of this study was to identify the effects of supplementation source and level of Zn to mitigate the negative effects of long-term, cyclic heat stress in finishing swine. Six hundred cross-bred pigs were housed under thermoneutral (TN) or cyclic heat (HS) conditions simulating summer heat with acute 3-d heat waves for a 70-d study. Thermoneutral conditions were 16.7 to 18.9 °C throughout the study. HS pigs were housed at the same temperature as TN from days 0 to 18, then 28 °C/24 °C for 12 h/12 h on days 18 to 21, followed by 30 °C/26.7 °C for 12 h/12 h on days 24 to 70, except during acute heat (32 to 33 °C/29 to 30 °C, 12 h/12 h) on days 21 to 24, 42 to 45, and 63 to 66. Treatments were arranged in a 2 × 6 factorial with main effects of environment (HS vs. TN) and dietary available Zn supplementation: (1) 50 mg/kg zinc oxide (ZnO), (2) 130 mg/kg ZnO, (3) 50 mg/kg of organic Zn (Availa Zn), (4) 50 mg/kg ZnO + 40 mg/kg organic Zn, (5) 50 mg/kg ZnO + 60 mg/kg organic Zn, and (6) 50 mg/kg ZnO + 80 mg/kg organic Zn. Pigs (5 pigs/pen) were blocked by initial body weight (72.2 kg) and randomly allotted to 1 of 12 temperature and diet treatment combinations across 10 replicates. Body weight and feed intake were determined at the beginning and end of each acute heat event. All pigs were ultrasonically scanned at the 10th rib (TR) to predict loin muscle area (LMA), backfat (BF), and percent lean. Data were analyzed by the MIXED procedure in SAS with pen as the experimental unit. At day 63, HS pigs were lighter (P < 0.05), had lower overall average daily gain (ADG; P < 0.05) and average daily feed intake (P < 0.05). A diet-by-environment interaction was observed for overall ADG (P < 0.05) with diet 5 HS pigs having a 3.9% reduction in ADG whereas diet 6 had 14.4% reduction in ADG, while under TN temperatures diet 6 had the greatest overall ADG of all treatments. Other diets were intermediate in their ADG under both HS and TN conditions. Pigs under HS had less BF at the TR (P < 0.05) and a smaller LMA (P < 0.05), and a greater calculated percent lean (P < 0.05). Our results indicate that a blend of supplemental Zn sources at 50/60 mg/kg may mitigate the reduction in growth performance due to HS. While not directly contrasted, the NRC requirement of 50 mg/kg Zn may be too low to optimize finishing pig growth performance under both TN and HS conditions.
PubDate: Tue, 02 Apr 2024 00:00:00 GMT
DOI: 10.1093/tas/txae029
Issue No: Vol. 8 (2024)
- Administering the maternal appeasing substance before slaughter to improve
carcass characteristics of finishing cattle
First page: txae048
Abstract: AbstractTwo experiments evaluated carcass characteristics of finishing steers administered the maternal bovine appeasing substance (mBAS) prior to slaughter. In Exp. 1, 954 Angus-influenced finishing steers housed in 6 original pens were used. Each original pen was split into a pair of experimental pens 14.3 d ± 3 d prior to slaughter, in a manner that number of steers and average pen body weight (BW; 636 ± 4 kg) were similar. An oiler containing mBAS (Ferappease Finish Cattle 5%; FERA Diagnostics and Biologicals; College Station, TX) was added to one of the experimental pens 7 d prior to slaughter (n = 6), whereas the other pen did not contain an oiler (CON; n = 6). The oiler delivered 120 mL of mBAS/steer during a 7-d period. Steer BW was recorded 7 d prior to and during loading (final BW) to the packing plant. No treatment effects were detected (P ≥ 0.51) for BW gain, final BW, and proportion of carcasses that graded Choice or Prime. Carcass dressing percentage was greater (P = 0.02) in mBAS compared with CON steers (65.9% vs. 64.2%; SEM = 0.5), which was not sufficient to impact hot carcass weight (HCW; P = 0.29). Incidence of dark-cutting carcasses did not differ between treatments (P = 0.23). In Exp. 2, 80 Angus-influenced finishing steers housed in 16 pens (5 steers/pen; 600 ± 4 kg of BW) were used. Pens were arranged in 4 rows of 4 pens/row, and rows were alternately assigned to receive an oiler containing mBAS (n = 8) or mineral oil (CON+; n = 8) 7 d prior to slaughter. Oilers were designed to deliver 120 mL/steer of mBAS or mineral oil during the 7-d period. Steer BW was recorded as in Exp. 1, and a blood sample was collected during exsanguination. No treatment effects were detected (P ≥ 0.20) for BW parameters, carcass marbling score, backfat thickness, Longissimus muscle area, yield grade, and proportion of carcasses that graded Choice or Prime. Carcass dressing was greater (P = 0.02) in mBAS steers compared with CON + (60.6 vs. 59.6%; SEM = 0.3) but HCW did not differ (P = 0.47) between treatments. Plasma cortisol concentration was less (P < 0.01) in mBAS steers compared with CON + (11.7 vs. 20.8 ng/mL; SEM = 1.6). Incidence of dark-cutting carcasses did not differ (P = 0.53) between treatments. In summary, mBAS administration to finishing cattle using oilers during the last 7 d on feed alleviated the adrenocortical stress response elicited by the process of slaughter, which likely resulted in increased carcass dressing.
PubDate: Tue, 02 Apr 2024 00:00:00 GMT
DOI: 10.1093/tas/txae048
Issue No: Vol. 8 (2024)
- Effects of increasing dietary arginine supply during the three first weeks
after weaning on pig growth performance, plasma amino acid concentrations,
and health status
First page: txae047
Abstract: AbstractA total of 425 weaned pigs (Exp. 1: 225 pigs [5.8 ± 0.9 kg]; Exp. 2: 200 pigs [6.1 ± 1.2 kg]) were used to determine the optimal dietary standardized ileal digestible (SID) arginine (Arg) level in early nursery diets based on growth and health responses. The basal diet in Exp.1 was formulated to meet SID Arg recommendation (0.66%; NRC, 2012) and in Exp. 2, SID Arg was set to simulate current industry practices for feeding nursery pigs (1.15 %). Basal diets were supplemented with 0.3%, 0.6%, 0.9%, and 1.2% of l-arginine to provide five levels of dietary SID Arg. Experimental diets were fed during phases I (days 0 to 7) and II (days 8 to 21) with common diets until market. Feed disappearance and body weight (BW) were measured on days 7, 14, 21, and 43. Final BW was recorded at first removal of pigs for market. Pen fecal score was assigned daily from days 0 to 21. Plasma immunoglobulin A (IgA) was determined on days 0, 7, and 14 and amino acids (AAs) concentration and plasma urea nitrogen (PUN) on days 0 and 14. Orthogonal polynomial contrasts were used to determine the linear and quadratic effects of dietary Arg. Optimal SID Arg was determined by fitting the data with piecewise regression, using growth performance as the primary response variable. In Exp. 1, dietary Arg linearly increased (P < 0.1) BW, average daily gain (ADG), and gain to feed ratio (G:F) ratio on day 21, as well as reduced (χ2 = 0.004) the percentage of pigs that lost weight (PLW) in week 1 by 29%. Dietary Arg resulted in linear improvement (P = 0.082) of ADG for the overall nursery period and quadratic improvement (P < 0.1) of final BW at marketing. In Exp. 2, dietary Arg linearly increased (P < 0.05) ADG and average daily feed intake (ADFI) in week 1, BW and ADFI (P < 0.1) on day 14, as well as reduced (χ2 ≤ 0.001) PLW in week 1. From days 0 to 21, G:F was improved quadratically (P < 0.1). Dietary Arg linearly increased (P < 0.1) ADG and BW on day 43. Dietary Arg supplementation decreased the incidence (χ2 < 0.05) of soft and watery feces during the first weeks after weaning and lower concentration of plasma IgA on days 7 and 14. Dietary Arg linearly and/or quadratically influenced plasma AA concentrations (P < 0.05), including an increase in Arg, Leu, Phe, Val, citrulline, ornithine, and PUN concentrations. Overall, weaned pigs exhibit optimal nursery growth performance and health when provided with dietary SID Arg ranging from 1.5% to 1.9%. This dietary range contributes to a reduction in the occurrence of fall-back pigs and improvements in final BW at marketing.
PubDate: Mon, 01 Apr 2024 00:00:00 GMT
DOI: 10.1093/tas/txae047
Issue No: Vol. 8 (2024)
- Genetic impact of external Targhee sires at the U.S. Sheep Experiment
Station: a case study of introgression
First page: txae044
Abstract: AbstractSheep breeders requested that the U.S. Sheep Experiment Station (USSES) to participate in national genetic evaluation through the National Sheep Improvement Program (NSIP). The reasons included the need for (1) a comparison of the productivity of industry and United States Department of Agriculture (USDA) lines, (2) transparency of USDA flocks, (3) genetic ties for NSIP by sampling of industry flocks, and (4) development of premium genetic lines for public release. In response, USSES began to incorporate external sires from NSIP participating flocks into the USSES Targhee flock. Our objective, based on a pedigree analysis, was to test if introgression of external genetics into the flock was achieved. The pedigree included 13,189 animals with mean maximum generations, mean complete generations, and mean equivalent complete generations of 4.2, 1.8, and 2.6, respectively. The mean generation interval was 3.1 yr. The reference population was defined as lambs born from 2021 to 2023 (n = 792). Two additional populations were defined as the current mature ewe flock (n = 123) and the current mature rams (n = 14). The Genetic Conservation Index averaged 7.7 for the full population and 25.7 for the reference population. Overall inbreeding was 0.003 for the full population and 0.006 for the reference population. The rate of inbreeding was 0.0003 per generation. Average relatedness was 0.015 for the full population and 0.018 for the reference population. The effective number of founders, effective number of ancestors, and founder genome equivalents contributing to the reference population were 60, 39, and 19.1, respectively. The ratio of the effective number of founders to the effective number of ancestors was 1.5, indicating the presence of genetic bottlenecks. Measures of effective population size ranged from 102 to 547. Of the 704 offspring produced by external sires, 17 ram lambs and 132 ewe lambs were retained for breeding. The USSES sires produced 299 offspring with 2 ram lambs and 51 ewe lambs retained. Incorporating external sires resulted in a cumulative percentage of genetic variance of 48.8, 49.1, and 44.2 of external genetics for the reference population, current mature ewe flock, and current mature rams, respectively. Stakeholder needs were addressed by introgression of external sires and participation in NSIP, but future selection practices need to be modified to maintain a minimum of 50% USSES core genetics in the flock.
PubDate: Tue, 26 Mar 2024 00:00:00 GMT
DOI: 10.1093/tas/txae044
Issue No: Vol. 8 (2024)
- Influence of BOVAMINE DEFEND Plus on growth performance, carcass
characteristics, estimated dry matter digestibility, rumen fermentation
characteristics, and immune function in finishing beef steers
First page: txae045
Abstract: AbstractOne hundred and eighty crossbred beef steers (406.0 ± 2.2 kg) were used to determine the impact of a novel direct-fed microbial (DFM) on growth performance, carcass characteristics, rumen fermentation characteristics, and immune response in finishing beef cattle. Steers were blocked by body weight (BW) and randomly assigned, within block, to 1 of 2 treatments (3 replicates/treatment: 30 steers/replicate). Treatments included: (1) no DFM (control) and (2) DFM supplementation at 50 mg ∙ animal−1 ∙ d−1 (BOVAMINE DEFEND Plus). All steers were fed a high-concentrate finishing diet and individual feed intake was recorded daily via the GrowSafe system. BWs were collected every 28 d. On day 55, 10 steers per pen were injected with ovalbumin (OVA). Jugular blood samples were collected from each steer on days 0, 7, 14, and 21 post injection. On day 112, the same steers were injected again with OVA and intramuscularly with a pig red blood cell solution. Jugular blood samples were collected from each steer on days 0, 7, 14, and 21 post injection. On day 124, rumen fluid was collected from 3 steers per treatment and used to estimate in vitro rumen fermentation characteristics. Equal numbers of steers per treatment were transported to a commercial abattoir on days 145, 167, and 185 of the experiment, harvested, and carcass data were collected. Initial BW was similar across treatments. On days 28 and 55, steers receiving DFM had heavier BW (P < 0.01) compared to controls. The average daily gain was greater in DFM-supplemented steers from days 0 to 28 (P < 0.01) and days 0 to 55 (P < 0.01) of the experiment compared to controls. Overall dry matter intake (DMI) was greater (P < 0.04) and overall feed efficiency was similar in DFM-supplemented steers compared to controls. Dressing percentage (P < 0.02) was greater in steers receiving DFM compared to controls. Antibody titers to injected antigens were similar across treatments. However, red blood cell superoxide dismutase activity was greater (P < 0.05) in DFM-supplemented steers compared to controls. In vitro molar proportions of isobutyric and butyric acid were greater (P < 0.01) and dry matter (DM) digestibility tended (P < 0.07) to be greater in rumen fluid obtained from steers supplemented with DFM. These data suggest that BOVAMINE DEFEND Plus supplementation improves growth performance during the initial period of the finishing phase, increases overall DMI and dressing percentage, and may impact antioxidant status in beef cattle.
PubDate: Mon, 25 Mar 2024 00:00:00 GMT
DOI: 10.1093/tas/txae045
Issue No: Vol. 8 (2024)
- The impact of sire breed on feedlot performance and carcass
characteristics of beef × Holstein steers
First page: txae043
Abstract: AbstractDairy herds are mating a portion of cows to beef cattle semen to create a value-added calf. Objectives of this study were to compare the feedlot performance and carcass characteristics of beef × Holstein steers by breed when sires represented bulls with commercially available semen. Three groups of single-born, male calves (n = 262) born to Holstein dams on 10 Pennsylvania dairies were sourced during 3 yr. Steers were sired by seven beef breeds: Angus, Charolais, Limousin, Hereford, Red Angus, Simmental, and Wagyu. Steers were picked up within a week of age and raised at two preweaned calf facilities until weaning (8 ± 1 wk of age) under similar health and management protocols. Steers were then transported to a commercial calf growing facility where they were managed as a single group until 10 ± 2 mo of age when they were moved to be finished at the Pennsylvania Department of Agriculture’s Livestock Evaluation Center feedlot. Groups of steers were selected for slaughter based on body weight. Carcass characteristics were evaluated by trained personnel and a three-rib section of the longissimus muscle (LM) was collected from each carcass for Warner-Bratzler shear force (WBSF) evaluation and intramuscular fat determination. Steers sired by all sire breeds except for Limousin had greater average daily gain (ADG; 1.62 to 1.76 kg/d) than Wagyu × Holstein steers (1.39 kg/d; P < 0.05). Angus-sired steers had an 8.6% greater ADG than Red Angus-sired steers (P < 0.05). Angus, Charolais (1.73 kg/d), and Simmental-sired steers (1.68 kg/d) also had greater ADG than Limousin-sired steers (1.55 kg/d; P < 0.05). Wagyu × Holstein steers spent 5 to 26 more days on feed (P < 0.05) than Limousin × Holstein, Simmental × Holstein, Angus × Holstein, and Charolais × Holstein steers. Angus and Charolais-sired steers were also on feed for 19 and 21 d fewer, respectively, than Limousin-sired steers (P < 0.05). Red Angus-sired steers had greater marbling scores than Simmental and Limousin-sired steers and Angus and Charolais-sired steers had greater marbling scores than Limousin-sired steers (P < 0.05). Angus, Limousin, and Hereford-sired steers produced the most tender LM as evaluated by WBSF; Angus-sired carcasses (3.82 kg) were more tender than Charolais (4.30 kg) and Simmental-sired carcasses (4.51 kg; P < 0.05). Limousin and Hereford-sired steers (3.70 and 3.83 kg, respectively) also had more tender steaks than Simmental-sired steers.
PubDate: Sat, 23 Mar 2024 00:00:00 GMT
DOI: 10.1093/tas/txae043
Issue No: Vol. 8 (2024)
- Parity affects mammary development in late-pregnant swine
First page: txae037
Abstract: AbstractThe goal of this project was to determine whether various measures of mammary development differed between gilts and multiparous sows at the end of gestation. During gestation, Yorkshire × Landrace gilts (n = 19) and sows (second and third gestations, n = 17) were fed one daily meal of a conventional corn-based diet, where the amount fed was based on body weight (BW) and backfat thickness (BF) at mating. On day 110 ± 1 of gestation, a jugular blood sample was obtained from all gilts and sows to measure insulin-like growth factor-1 (IGF-1), glucose, free fatty acids, and urea. On that same day, BW and BF were measured and animals were euthanized. Mammary glands from one side of the udder were dissected for compositional analyses. The fifth gland of the contralateral row of mammary glands was sampled for histology and immunohistochemical localization of Ki67. There was less total parenchyma (1,437.4 vs. 2,004.7 ± 127.1 g; P < 0.001) and total extraparenchymal tissue (1,691.0 vs. 2,407.0 ± 125.3 g; P < 0.001) in mammary glands of gilts compared to those from sows. When these values were expressed per kg BW (226.0 and 284.0 ± 2.7 kg for gilts and sows, respectively), parenchymal mass did not differ (P > 0.10), while extraparenchymal tissue weight tended to be less in gilts than sows (P = 0.07). All components within the parenchyma differed by parity (P < 0.001). Specifically, parenchymal tissue from gilts contained a greater proportion of fat and dry matter (DM), a lower proportion of protein, and lower concentrations of DNA (6.59 vs. 9.35 ± 0.53 mg/g DM) and RNA (7.76 vs. 12.33 ± 0.70 mg/g DM) than that from sows. On the other hand, the circumference of alveolar lumens was greater in gilts than sows (P < 0.001), while the percentage of epithelial cells that were positive for Ki67, a marker of cell proliferation, was greater in sows than gilts (P < 0.05). Circulating concentrations of IGF-1 were greater in gilts than in multiparous sows (45.0 vs. 27.3 ± 2.8 ng/mL, P < 0.001). None of the other blood variables were changed by parity. Results show a marked effect of parity on mammary gland development in swine. At the end of gestation, the mammary glands of gilts had less parenchyma with lower epithelial proliferation than glands from multiparous sows. These differences could alter the response of mammary tissue to various nutritional or endocrine signals. This information is crucial for the development of management strategies designed to maximize sow milk yield.
PubDate: Sat, 23 Mar 2024 00:00:00 GMT
DOI: 10.1093/tas/txae037
Issue No: Vol. 8 (2024)
- Employee perception of precision technology use at the dairy farm
First page: txae036
Abstract: AbstractThe adoption of precision technologies on dairy farms has increased significantly in recent decades, leading to the challenge of providing employees with resources to maximize the efficient use of these tools. The objective of this study was to explore how dairy farm employees perceive the available precision technologies and to identify possible challenges they face when adapting to their use at the farm. An online survey consisting of four sections (employee demographics, precision technologies in use, perception of these technologies, and opportunities for adapting to technology use) was completed from September to December 2022 by 266 farm employees from three dairies operated under similar management. Most of the respondents were identified as male (72.2%), Hispanic or Latino (92.5%), aged between 21 and 30 (39.1%) or 31 and 40 yr (36.8%), with a bachelor’s degree (34.6%) or completion of middle school (29.3%) and having basic or no English proficiency (74%). Overall, the respondents indicated being comfortable (95.6%) with and understanding (91.8%) the technology they use. Employees recognized precision technology as a tool that helps them to be more efficient (93.7%), identifying the technologies’ benefits (92.1%). However, challenges for adapting to these technologies included personal limitations, such as not knowing the language of the technology (31%), visual impairments (24%), light sensitivity (14%), and not being able to read (7%). Environmental limitations were also recognized and included cold weather (64.3%), wind (46%), and surroundings that were too dark (31%) or too bright (21%). Significant associations between perception of the technology and age, level of education, and English proficiency were identified. Respondents indicated their desire to learn more about precision technologies implemented at work, which could eventually lead to improved efficiency at the dairy operation through innovations in the way users interact with these technologies, increasing employees’ motivation. This study provides insights that could assist the dairy industry in addressing challenges and enhancing opportunities for a more efficient use of precision technologies at dairy farms.
PubDate: Fri, 22 Mar 2024 00:00:00 GMT
DOI: 10.1093/tas/txae036
Issue No: Vol. 8 (2024)
- Replacing alfalfa hay with a novel alfalfa leaf pellet product (ProLEAF
MAX) and/or alfalfa stems (ProFiber Plus) in the diet of developing dairy
heifers alters dry matter intake, but does not negatively impact growth or
development
First page: txae038
Abstract: AbstractAlfalfa is a commonly grown forage in the Intermountain West region of the United States and is often included in the diet of dairy cattle. Alfalfa provides a variety of different nutrients, but the nutrient content of alfalfa varies depending on factors such as the soil, region, cutting, and climate. However, alfalfa leaves tend to have less variation in their nutrient content than alfalfa stems. Fractionating alfalfa may be one way to improve control of nutrients provided when developing a ration for developing dairy heifers. The purpose of this study was to determine whether including fractionated alfalfa in the diet impacts the growth or conception rates of developing dairy heifers. Heifers were allocated to one of three treatments: a control group fed a typical diet (CON; n = 8), a diet that replaced alfalfa with fractionated alfalfa leaf pellets and alfalfa stems (ProLEAF MAX + ProFiber Plus; PLM + PFP; n = 8), or a diet that replaced alfalfa with alfalfa stems (PFP; n = 8) for 85 d. Heifers were fed individually twice daily and weight, hip height (HH), and wither height (WH) were recorded every 14 d. Additionally, blood was collected every 28 d, and conception rates were recorded at the end of the trial. Heifers receiving the PFP diet consumed less dry matter (P = 0.001) than the CON treatment. Analyses were then conducted to determine nutrient intake and heifers receiving the PFP diet also consumed less neutral detergent fiber (P = 0.02), acid detergent fiber (P = 0.02), crude protein (P = 0.001), and net energy for maintenance (P = 0.001) than heifers consuming the CON diet; however, no differences (P > 0.10) were observed between heifers fed the CON and PLM + PFP diets. Analysis of body weight gain over the feeding period showed no difference (P = 0.52) among heifers consuming the different treatment diets. Additionally, treatment did not affect average daily gain (P = 0.49), gain:feed (P = 0.82), HH gain (P = 0.20), or WH gain (P = 0.44) among heifers receiving different diets. Treatment × time altered (P < 0.001) blood urea nitrogen when analyzed as a repeated measure. Total feed cost was lowest (P < 0.001) for the PFP diet and cost of gain tended (P = 0.09) to be increased for the PLM + PFP diet compared to the CON diet. Overall, these data indicate that including alfalfa stems in a developing heifer diet may decrease dry matter intake, lower input costs, and increase profitability, without negatively impacting growth.
PubDate: Tue, 19 Mar 2024 00:00:00 GMT
DOI: 10.1093/tas/txae038
Issue No: Vol. 8 (2024)
- Effect of creep feeding pelleted starter diet, liquid milk replacer and a
liquid mixture of starter diet and milk replacer to suckling pigs on their
growth and medication usage
First page: txae041
Abstract: AbstractThe aim of this study was to assess the effect of creep-feeding solid starter diet, liquid milk replacer, and a liquid mixture of starter diet and milk replacer to suckling pigs on their growth and medication usage up to target slaughter weight (approximately 120 kg). Ninety-one sows and their litters were randomly assigned to one of four post-farrowing treatments at day 107 of gestation; (1) no creep feed provided to weaning at day 28 of age (CONTROL; n = 20), (2) dry pelleted starter diet provided as creep feed from day 10 of age to weaning (DPS; n = 25), (3) liquid milk replacer provided as creep feed from day 3 of age to weaning (LMR; n = 23), and (4) liquid milk replacer provided from days 3 to 6 of age followed by a mixture of liquid milk replacer with an increasing proportion of liquid starter diet to weaning provided as creep feed (LMR + S; n = 23). Pig weight and dry matter disappearance (DMd) were recorded during lactation and postweaning until pigs reached target slaughter weight (approximately 120 kg). At target slaughter weight, carcass weight and quality were recorded. Medication (antibiotic and anti-inflammatory) usage per pig on a litter basis, and number of injections and clinical cases of disease per litter were recorded from birth to slaughter. At day 5 postweaning, a subset of pigs (n = 40) were sacrificed and intestinal samples were collected for histological analysis. Piglets supplemented with DPS had higher DMd of creep feed than those supplemented with LMR or LMR + S (P < 0.001). Providing LMR + S to suckling piglets reduced the coefficient of variation (CV) for within-litter piglet weaning weight (P < 0.01) compared to DPS and LMR, but the CV of LMR + S was similar to that of CONTROL. Providing DPS or LMR to suckling piglets increased piglet weaning weight compared to CONTROL (P < 0.001) but pig weight was not significantly different from CONTROL at time points thereafter. Gain to feed ratio from weaning to day 6 postweaning was less for LMR pigs compared to all other treatments (P < 0.001). Providing DPS or LMR + S to suckling piglets tended to increase postweaning ileal villus height (P = 0.07). Diarrhea incidence, as well as the number of clinical cases of disease and injections per litter and volume of antibiotic and anti-inflammatory administered per pig pre- and postweaning, were not affected by treatment (P > 0.05). In conclusion, supplementing suckling pigs with liquid milk replacer or dry pelleted starter diet improved growth at weaning, but the benefit did not persist to slaughter.
PubDate: Sat, 16 Mar 2024 00:00:00 GMT
DOI: 10.1093/tas/txae041
Issue No: Vol. 8 (2024)
- Quantification of cooling effects on basic tissue measurements and exposed
cross-sectional brain area of cadaver heads from Holstein cows > 30 mo
of age
First page: txae042
Abstract: AbstractPenetrating captive bolt (PCB) is the primary method of preslaughter stunning for cattle and is also used for on-farm euthanasia. The objective of this study was to quantify the impact of cooling on the soft tissue thickness, cranial thickness, total tissue thickness, and cross-sectional brain area of cadaver heads collected from mature (> 30 mo of age) dairy cows following the application of a PCB stun in a frontal placement. Hide-on cadaver heads were obtained from culled dairy cows (N = 37) stunned in a frontal location using a handheld PCB device (Jarvis Model PAS—Type C 0.25R Caliber Captive Bolt, Long Bolt) at a commercial slaughter establishment. Following transport to the University of Wisconsin—River Falls, heads were split at midline along the bolt path by a bandsaw and then underwent FRESH, CHILL24, CHILL48, and CHILL72 refrigeration treatments. The FRESH treatment involved images collected immediately after splitting each head, the CHILL24 treatment involved images collected after 24 h of refrigeration, the CHIL48 treatment involved images collected after 48 h of refrigeration, and the CHILL72 treatment involved images collected after 72 h of refrigeration. Measurements of soft tissue thickness, cranial thickness, total tissue thickness, and cross-sectional brain area were recorded for each refrigeration treatment. Soft tissue thickness did not differ caudal to (P = 0.3751) or rostral to (P = 0.2555) the bolt path. Cranial thickness did not differ caudal to (P = 0.9281) or rostral to (P = 0.9051) the bolt path. Total tissue thickness did not differ caudal to (P = 0.9225; FRESH: 24.77 mm, CHILL24: 23.93 mm, CHILL48: 24.27 mm, CHILL72: 42.30, SE: 0.86) or rostral to (P = 0.8931; FRESH: 24.09 mm, CHILL24: 23.99, CHILL48: 24.26, CHILL72: 24.43 mm, SE: 0.79 mm) the bolt path. Cross-sectional brain area was not different (P = 0.0971) between refrigeration treatments (FRESH: 9,829.65 ± 163.87 mm2, CHILL24: 10,012.00 ± 163.87 mm2, CHILL48: 9,672.43 ± 163.87 mm2, CHILL72: 10,235.00 ± 166.34 mm2). This study demonstrated that FRESH tissue parameters can be determined from cattle cadaver heads refrigerated for 24, 48, or 72 h.
PubDate: Sat, 16 Mar 2024 00:00:00 GMT
DOI: 10.1093/tas/txae042
Issue No: Vol. 8 (2024)
- Data analytics-based evaluation of blood indices and adaptation of
medicated and non-medicated broiler chickens under humid tropical
conditions
First page: txae040
Abstract: AbstractThe growth performance and blood indices of medicated and non-medicated broiler chickens have been the subject of this research coupled with a paucity of comparative information on what can actually happen to broiler chickens if not medicated when reared under humid tropical conditions. One hundred unsexed day-old broilers were randomly and equally allotted into two treatment groups of TM (medicated) and TN (non-medicated) in a completely randomized design each treatment with five replicates having ten birds each. The birds were reared on deep litter system for 56 d which was divided into two phases of 28 d each (starter and finisher), during which data were collected with respect to daily feed intake, final body weight, body weight gained (BWG), mortality rate while blood analysis was carried out on 28th and 56th d for starter and finisher phases, respectively. Non-medicated group served as control. Feed conversion ratio (FCR) and feed conversion efficiency (FCE), were later calculated. Data collected were subjected to analysis of variance statistically. There was no significant difference between the medicated and non-medicated broilers for daily feed intake, final body weight, and BWG and also for the blood parameters investigated at starter phase. However, at finisher phase, no significant difference was observed in the daily feed intake of Tm and Tn but there was significant (P < 0.05) difference in the final body weight, BWG, FCR, FCE, and mortality rate between the two groups. Birds on Tm attained higher weight significantly (P < 0.05) than those on TN. BWG, FCR, and FCE followed the same trend and also the mortality rate. White blood cells count of TN was higher significantly (P < 0.05) than TM while TM birds recorded higher packed cell volume, red blood counts, and hemoglobin concentration (Hb) significantly (P < 0.05) than TM birds. Effect of medication was much noticeable at finisher phase as it improved the growth rate though mortality rate was close to that of TN group. These results suggest that broilers can be produced free of medication with good feeding without loss of birds while the growth rate can be enhanced with the use of prebiotics and prebiotics.
PubDate: Sat, 16 Mar 2024 00:00:00 GMT
DOI: 10.1093/tas/txae040
Issue No: Vol. 8 (2024)
- Concerns about the use of antimicrobials in swine herds and alternative
trends
First page: txae039
Abstract: AbstractPig productivity in Brazil has advanced a lot in recent decades. Specialized breeds are more vulnerable to pathogens, which has boosted the use of antimicrobials by farmers. The selective pressure generated favors the emergence of resistant bacteria, which compromises the effectiveness of this treatment and limits therapeutic options. In addition to increasing costs and mortality rates in the production system, public awareness of this issue has increased. The authorities have imposed restrictive measures to control the use of antimicrobials and have banned their use as growth promoters. This literature review highlights biosecurity and animal welfare to prevent pig diseases. Hence, we describe alternatives to the use of antimicrobials in pig production for the selection of effective non-antibiotic feed additives that help maintain good health and help the pig resist disease when infection occurs.
PubDate: Sat, 16 Mar 2024 00:00:00 GMT
DOI: 10.1093/tas/txae039
Issue No: Vol. 8 (2024)
- Energy efficiency of grazing Hereford heifers classified by paternal
residual feed intake
First page: txae005
Abstract: AbstractResidual feed intake (RFI) has become a widely spread index of feed efficiency. Although most of beef cattle systems in the world are pasture based, RFI evaluation and research is usually performed in confinement conditions. In this context, residual heat production (RHP) estimated as the difference between actual and expected heat production (HP), could allow to identify efficient animals. Thus, the aim of this work was to evaluate the relationship between paternal estimated breeding values (EBV) for RFI and beef heifer efficiency, measured as RHP, as well as its association with heifers’ productive and reproductive performance on grazing conditions. Seventy-one 25 ± 0.8-mo-old and seventy-four 24 ± 0.7-mo-old Hereford heifers were managed as contemporary groups in spring 2019 and 2020, respectively. Heifers were sired by 10 RFI-evaluated bulls and classified into three groups according to the paternal EBV for RFI: five bulls of low RFI (high efficiency, pHE), two bulls of medium RFI (medium efficiency), and three bulls of high RFI (low efficiency, pLE). The experimental period lasted 70 d prior to their first insemination where HP was determined by the heart rate-O2 pulse technique. In addition, reproductive performances during the first and second breeding and calving seasons were recorded. Heifers’ RHPs expressed as MJ/d and kJ/kg of body weight (BW)0.75/d were positively correlated with paternal RFI EBVs (P < 0.05; r > 0.60). Moreover, BW and average daily gain (ADG) were greater (P < 0.01) for pHE than pLE heifers while expressed as units of BW0.75/d, neither total HP nor metabolizable energy (ME) intake differed between groups, but pHE heifers had greater retained energy (RE; P < 0.01) and lower RHP (P < 0.05) than pLE ones. Gross energy efficiency (RE/ME intake) was greater (P < 0.001) for pHE than pLE heifers while the HP/ADG and RHP/ADG were reduced (P < 0.05) and feed-to-gain ratio (ADG/DM intake) tended to be greater (P = 0.07) for pHE than pLE heifers. In addition, during the first breeding and calving seasons, small but significant (P < 0.01) differences in reproductive responses between groups suggested an earlier pregnancy in pHE heifers than the pLE group, differences that disappeared during the second breeding and calving seasons. Thus, heifers sired by high-efficiency bulls measured as RFI were more efficient measured as RHP in grazing conditions, without significant differences in reproductive performance.
PubDate: Thu, 14 Mar 2024 00:00:00 GMT
DOI: 10.1093/tas/txae005
Issue No: Vol. 8 (2024)
- Preslaughter factors affecting mobility, blood parameters, bruising, and
muscle pH of finished beef cattle in the United States
First page: txae035
Abstract: AbstractDecades of work have focused on reducing fear, stress, and discomfort in cattle during the preslaughter phase by improving and promoting animal handling, transportation, and management processes. Even still, there is limited information about the effects of preslaughter factors on animal welfare and meat quality outcomes in finished cattle in the United States. This study aimed to track individual animals through the slaughter process to identify preslaughter factors associated with key welfare and quality outcomes. A total of 454 cattle from one commercial slaughter facility were studied. Preslaughter factors assessed included distance traveled, truck waiting time, lairage density, lairage duration, and season. Animal characteristics, i.e., body weight, breed, and sex, were also recorded. One trained observer scored the mobility of all cattle using the North American Meat Institute’s 1-4 scale (i.e., normal to extremely reluctant to move). Exsanguination blood was collected and analyzed for cortisol, creatine kinase, and lactate. Carcass bruising was scored using a modified version of the National Beef Quality Audit’s bruise-scoring methodology (i.e., no bruise, one bruise ≤ the size of a deck of cards, one bruise > than the size of a deck of cards, and multiple bruises). Ultimate muscle pH was measured 32 to 36 h postmortem. Multi-predictor models were selected for each outcome variable using Akaike Information Criterion. Continuous outcome variables were analyzed using linear mixed-effect models and categorical outcome variables with mixed-effect logistic regression models. Longer truck waiting times were associated with increased cortisol (P = 0.04) and lactate (P = 0.02) concentrations. Similarly, increased lairage duration was associated with increased creatine kinase concentrations (P = 0.05) and the odds of cattle being bruised (P = 0.03). Less space allowance per animal in lairage was associated with increased odds of cattle having impaired mobility (P = 0.01). There was a seasonal effect for many of the measured outcomes; the summer season was associated with greater lactate concentrations (P < 0.0001), increased odds of impaired mobility (P < 0.0001), and increased odds of carcass bruising (P = 0.003). The findings of this study indicate that many of the preslaughter factors assessed influence critical welfare and meat quality outcomes of finished beef cattle, warranting future research and consideration.
PubDate: Wed, 13 Mar 2024 00:00:00 GMT
DOI: 10.1093/tas/txae035
Issue No: Vol. 8 (2024)
- National Beef Quality Audit-2022 Phase 1: face-to-face and digital
interviews
First page: txae034
Abstract: AbstractThe National Beef Quality Audit (NBQA) has been conducted regularly since 1991 to assess and benchmark quality in the U.S. beef industry, with the most recent iteration conducted in 2022. The goal of NBQA Phase I is to evaluate what needs to be managed to improve beef quality and demand. Interviews (n = 130) of industry personnel were conducted with the aid of routing software. In total, packers (n = 24), retailers (n = 20), further processors (n = 26), foodservice (n = 18), and allied government agencies and trade organizations (n = 42) were interviewed. Interviews were routed in software based on interviewee involvement in either the fed steer and heifer market cow and bull sectors, or both. Interviews were structured to elicit random responses in the order of determining “must-have” criteria (quality factors that are required to make a purchase), best/worst ranking (of quality factors based on importance), how interviewees defined quality terms, a strength, weakness, opportunities, threats (SWOT) analysis, general beef industry questions, and sustainability goals (the latter four being open-ended). Quality factors were 1) visual characteristics, 2) cattle genetics, 3) food safety, 4) eating satisfaction, 5) animal well-being, 6) weight and size, and 7) lean, fat, and bone. Best/worst analysis revealed that “food safety” was the most (P < 0.05) important factor in beef purchasing decisions for all market sectors and frequently was described as “everything” and “a way of business.” Culture surrounding food safety changed compared to previous NBQAs with interviewees no longer considering food safety as a purchasing criterion, but rather as a market expectation. The SWOT analysis indicated that “eating quality of U.S. beef” was the greatest strength, and cited that educating both consumers and producers on beef production would benefit the industry. Irrespective of whether companies’ products were fed or market cow/bull beef, respondents said that they believed “environmental concerns” were among the major threats to the industry. Perceived image of the beef industry in the market sectors has improved since NBQA-2016 for both fed cattle and market cow/bull beef.
PubDate: Tue, 12 Mar 2024 00:00:00 GMT
DOI: 10.1093/tas/txae034
Issue No: Vol. 8 (2024)
- National Beef Quality Audit—2022: Transportation, mobility, live cattle,
and hide assessments to determine producer-related defects that affect
animal welfare and the value of market cows and bulls at processing
facilities
First page: txae033
Abstract: AbstractThe National Beef Quality Audit (NBQA)-2022 serves as a benchmark of the current market cow and bull sectors of the U.S. beef industry and allows comparison to previous audits as a method of monitoring industry progress. From September 2021 through May 2022, livestock trailers (n = 125), live animals (n = 5,430), and post-slaughter hide-on animals (n = 6,674) were surveyed at 20 commercial beef processing facilities across the U.S. Cattle were transported in a variety of trailer types for an average distance of 490.6 km and a mean transport time of 6.3 h. During transit, cattle averaged 2.3 m2 of trailer space per animal indicating sufficient space was provided according to industry guidelines. Of all trailers surveyed, 55.3% transported cattle from an auction barn to a processing facility. When surveyed, 63.6% of all truck drivers reported to be Beef Quality Assurance certified. The majority (77.0%) of cattle were sound when evaluated for mobility. Mean body condition scores (9-point scale) for beef cows and bulls were 3.8 and 4.4, respectively, whereas mean body condition scores (5-point scale) for dairy cows and bulls were 2.3 and 2.6, respectively. Of the cattle surveyed, 45.1% had no visible live animal defects, and 37.9% had only a single defect. Of defects present in cows, 64.6% were attributed to an udder problem. Full udders were observed in 47.5% of all cows. Nearly all cattle were free of visible abscesses and knots (97.9% and 98.2%, respectively). No horns were observed in 89.4% of all cattle surveyed. Beef cattle were predominantly black-hided (68.9% and 67.4% of cows and bulls, respectively). Holstein was the predominant dairy animal observed and accounted for 85.7% of the cows and 98.0% of the bulls. Only 3.1% of all animals had no form of identification. Findings from the NBQA-2022 show improvements within the industry and identify areas that require continued education and research to improve market cow and bull welfare and beef quality.
PubDate: Mon, 11 Mar 2024 00:00:00 GMT
DOI: 10.1093/tas/txae033
Issue No: Vol. 8 (2024)
- An updated meta-analysis of the anti-methanogenic effects of monensin in
beef cattle
First page: txae032
Abstract: AbstractMeta-analyses were performed to quantitatively summarize the effects of monensin on in vivo methane (CH4) production in beef cattle, and differentiate these outcomes according to dietary management, dose of monensin, and length of monensin supplementation. Data from 11 manuscripts describing 20 individual studies were used, and CH4 was converted to g/d when required. Studies were classified according to dose of monensin (mg/kg of diet dry matter), length of monensin supplementation prior to the last CH4 measurement, feeding management (ad libitum vs. limited-fed), and diet profile (high-forage or high-concentrate diets). Variance among studies were assessed using a χ² test of heterogeneity and calculated using I² statistics. The inclusion of monensin decreased (P < 0.01) CH4 production by 17.5 g/d when all studies were analyzed together. A moderate (P < 0.01) heterogeneity (I² = 55%) was detected for CH4 production estimates between studies; thus, meta-analyses were performed within classes. The reduction in CH4 differed (P < 0.01) according to dose of monensin, as it decreased (P < 0.01) by 25.6 g/d when the high recommended dose range was used (32 to 44 mg/kg), and tended to decrease (P ≤ 0.07) by 9.7 and 13.5 g/d when the moderate (≤31 mg/kg) and above recommended (≥45 mg/kg) doses were used, respectively. The reduction in CH4 also differed (P < 0.01) according to the length of monensin supplementation. Monensin decreased (P ≤ 0.05) CH4 production by 24.3 g/d when supplemented for <15 d, by 15.4 g/d when supplemented from 23 to 33 d, by 24.3 g/d when supplemented from 52 to 79 d, and tended to decrease (P = 0.06) CH4 production by 3.21 g/d when supplemented from 94 to 161 d. The reduction in CH4 did not differ (P = 0.37) according to diet profile, despite a 30% difference in reduction when monensin was added to high-forage (20.89 g/d) compared with high-concentrate diets (14.6 g/d). The reduction in CH4 tended to differ according to feeding management (P = 0.08), decreasing by 22.9 g/d (P < 0.01) when monensin was added to diets offered ad libitum, and by 11.5 g/d (P = 0.05) in limit-fed diets. Collectively, this study provides novel insights and further corroborates monensin as CH4 mitigation strategy in beef cattle operations. The most effective responses were observed during the first 79 d of monensin supplementation, and when monensin was included between 32 to 44 mg/kg of diet, was added to high-forage diets, and added to diets fed ad libitum.
PubDate: Sat, 09 Mar 2024 00:00:00 GMT
DOI: 10.1093/tas/txae032
Issue No: Vol. 8 (2024)
- Cattle, carcass, economic, and estimated emission impacts of feeding
finishing steers lubabegron or ractopamine hydrochloride
First page: txae031
Abstract: AbstractLubabegron (Experior; Elanco, Greenfield, IN, USA) is the first U.S. Food and Drug Administration approved feed additive for reducing gas emissions from feedlot animals or their waste; it does not have live or carcass performance claims. Our primary objective was to determine the effect of lubabegron on feedlot performance and carcass traits in finishing beef steers compared to ractopamine hydrochloride (Optaflexx; Elanco, Greenfield, IN, USA). A commercial feedlot trial using cross-bred beef steers (n = 2,117; 373 ± 15 kg initial body weight [BW]) was completed with a randomized complete block design. Treatments consisted of two feed additives: (1) OPT targeted to deliver 300 mg/animal/d of ractopamine hydrochloride for 28 ± 7 d out from harvest and (2) EXP targeted to deliver 36 mg/animal/d of lubabegron 56 ± 7 d out from harvest and a 4-d preslaughter withdrawal period. Twenty 70 to 142 hd pens with 10 pens per treatment were used. Cattle were weighed at arrival processing and at harvest and fed for an average of 167 d. Data were used to calculate production metrics, partial budgets, and estimated greenhouse gas emissions using published methods, and were analyzed using linear mixed models with pen as the experimental unit and block as a random intercept. A statistical significance threshold of α = 0.05 was determined a priori. There was no evidence for statistically significant differences between treatments for initial BW (P = 0.70), health-related outcomes (P values ≥ 0.43), or mobility scores (P = 0.09). Cattle-fed EXP had increased final BW, ADG, G:F, and decreased dry matter intake (P values ≤ 0.01) compared to OPT. Carcasses were 11 ± 1.76 kg (hot carcass weight) heavier in EXP group (P < 0.01), and differed between treatments for both yield grades (YG) and quality grades distributions (P values ≤ 0.01). Cattle-fed EXP had a shift toward more YG 1 and 2, select and sub-select carcasses compared to OPT, which had as shift toward more YG 3, 4, 5, prime and choice carcasses. With increased beef production and efficiency compared to OPT, the estimated CO2 equivalent emissions from production were reduced by 6.2% per unit of carcass weight for EXP (P ≤ 0.01). Estimated net returns/animal shipped were $56.61 ± 9.37 more for EXP than OPT (P ≤ 0.01). In conclusion, when cattle were fed for the same total number of days, feeding EXP compared to OPT increased net returns, feedlot performance, and efficiency, but resulted in carcass yield and quality characteristics that may impact marketing programs.
PubDate: Fri, 08 Mar 2024 00:00:00 GMT
DOI: 10.1093/tas/txae031
Issue No: Vol. 8 (2024)
- Timing of dietary zinc additions during gestation for improved piglet
survival
First page: txae030
Abstract: AbstractThe objectives of this study were to determine a practical approach to feeding elevated dietary zinc (Zn) to gestating sows in a commercial setting and to confirm preweaning mortality could be reduced by feeding high Zn to sows during different periods of gestation. The study was conducted at a commercial sow farm in the upper Midwest. Mixed parity sows (n = 267) over three consecutive weekly farrowing groups (sows farrowing within 1 wk) were assigned randomly to one of the three dietary treatments within parity. Treatments consisted of: (1) control sows fed a corn–soybean meal diet containing 206 mg/kg total supplemental Zn supplied by zinc hydroxychloride; (2) breed-to-farrow: as control + 147 mg/kg supplemental Zn as ZnSO4 (353 mg/kg total supplemental Zn) fed from 5 d after breeding to farrowing; and (3) day 110-to-farrow: as control fed from breeding to farrowing + 4,079 mg/kg supplemental Zn as ZnSO4 (4,285 mg/kg total supplemental Zn) starting day 110 of gestation until farrowing. At farrowing, individual piglets were weighed and identified within 12 h of birth. Data were analyzed using PROC GLIMMIX of SAS and the model considered the fixed effect of dietary treatment and random effect of farrowing group. Dietary treatments did not affect number of total pigs born per litter. For breed-to-farrow sows, there was an increase in the percentage of pigs born alive compared to sows fed the control and day 110-to-farrow treatments (P < 0.001). The number of stillborn pigs expressed as a percentage of total litter size at birth decreased for breed-to-farrow sows (P < 0.001) compared with control or day 110-to-farrow sows. Mortality of low birth weight piglets from birth to weaning did not differ among dietary treatments (P = 0.305); however, a trend for decreasing post-natal mortality (P = 0.068) of normal birth weight pigs was observed for pigs born to sows fed elevated Zn 5 d before farrowing. In conclusion, feeding elevated Zn to sows throughout gestation increased the proportion of pigs born alive suggesting that elevated gestational Zn intake makes piglets more robust to endure the stresses of farrowing and decreases intrapartum mortality. Under the conditions of this study, elevated Zn intake of sows did not influence piglet post-natal survival. However, feeding high zinc throughout gestation may decrease piglet mortality during the parturition process.
PubDate: Fri, 08 Mar 2024 00:00:00 GMT
DOI: 10.1093/tas/txae030
Issue No: Vol. 8 (2024)
- Establishing the relationship between wildfire smoke and performance
metrics on finished beef cattle in Western Rangelands
First page: txae022
Abstract: AbstractIdentifying causal relationships is complicated. Researchers usually overlook causality behind relationships which can generate misleading associations. Herein, we carefully examine the parametric relationship and causality between wildfire smoke exposure and animal performance and behavior metrics over a period of 2 yr in Reno, Nevada. The animals in the 2020 smoke season were grain-finished (n = 12) and grass-finished (n = 12), whereas the animals during the 2021 season were fed under the same diet but finished with either a hormonal implant (n = 9), or without (n = 9). The dataset included daily records of feed intake (FI), body weight (BW), water intake (WI), average daily gain (ADG), and WI behavior (time spent drinking [TSD]; water intake events [WIE]; no-WIE [NWIE]). Variable tree length Bayesian additive regression trees (BART) were utilized to investigate the relationships between air quality index (AQI), particulate matter 2.5 μm (PM2.5) and 10 μm (PM10), NO2, SO2, Ozone, and CO levels in the air (sensors < 1.6 km from animals) with the animal data. Additionally, linear mixed models with a 7-d lag were used to evaluate parametric relationships among the same variables. All statistical analyses were performed on R Statistical Software (R Core Team 2023). Under the linear mixed model with a 7-d lag, significant positive and negative associations were found for all parameters examined (P < 0.05). Negative associations were found between FI, WI, ADG, BW, WIE, NWIE, TSD, and PM2.5 (P < 0.05) for at least one animal group. Positive linear associations between wildfire smoke parameters and the metrics evaluated were more variable and dependent on year, treatment, and smoke parameters. When examining the credible intervals and the variable importance in the BART, relationships were more difficult to identify. However, some associations were found for Ozone, AQI, NO2, CO, and PM10 (P < 0.05). Overall, our results carefully examine the relationship between smoke parameters and cattle performance and present interesting pathways previously unexplored that could guide early culling/finishing of animals to avoid economic losses associated with performance decrease in response to wildfire smoke exposure. Though interesting associations are found under linear mixed models, causality is difficult to establish, which highlights the need for controlled exposure experiments.
PubDate: Mon, 04 Mar 2024 00:00:00 GMT
DOI: 10.1093/tas/txae022
Issue No: Vol. 8 (2024)
- Effect of exogenous melatonin on the cellular response of Holstein heifer
calves during vaccination
First page: txae028
Abstract: AbstractDespite rigorous vaccination protocols, calf morbidity is the primary contributor to economic loss in the calf sector of the dairy industry. Melatonin has modulated immune response in other mature animal species. We hypothesized that exogenous melatonin may improve the cellular response to vaccination in dairy calves. Our objective was to evaluate the effect of exogenous melatonin on polymorphonuclear leukocyte (PMN) function in Holstein heifer calves during immunization. Sixty neonatal Holstein heifers were enrolled by birth cohort (block) and randomized to one of four treatments: control (CON), vaccination of 0.5 mg ovalbumin on days 0 and 21 (VAC), implantation of 24 mg melatonin on day 0 (MEL), or both melatonin and vaccine treatments (MVAC). Jugular blood was collected on days 0, 21, 42, and 63 to measure circulating melatonin, anti-ovalbumin immunoglobulin-G, and PMN function. Calves implanted with melatonin had greater circulating melatonin than non-implanted on day 21 (P < 0.01). Anti-ovalbumin IgG was greater for vaccinated than non-vaccinated calves (P < 0.01). Anti-ovalbumin IgG was greater for MVAC than VAC calves on day 63. Percent of cells and mean florescence intensity of cells performing oxidative burst decreased from day 0 to day 63 (P < 0.01) but were not affected by treatment (P ≥ 0.26). There was a tendency (P = 0.10) for an interaction of melatonin, vaccination, and day for the mean florescence intensity of cells performing phagocytosis where MVAC was greater than all other treatments on d 42. Exogenous melatonin may alter PMN function of calves during vaccination. Further research is needed to define the effect of melatonin on development of antigen-specific IgG during programmed vaccination protocols.
PubDate: Sat, 02 Mar 2024 00:00:00 GMT
DOI: 10.1093/tas/txae028
Issue No: Vol. 8 (2024)
- The effects of dietary net energy on grow-finish performance and carcass
characteristics of male market pigs managed with immunological castration
(Improvest)
First page: txae027
Abstract: AbstractThe objective was to determine the effects of dietary net energy (NE) during the grow-finish period on live performance and carcass characteristics of intact male pigs managed with immunological castration (Improvest) compared with physically castrated (PC) male pigs. The 101-d study began when 1,008 pigs (504 intact male pigs and 504 PC male pigs; 10 wk old) were allocated by weight to 48 pens with 21 intact males or 21 PC males per pen. Three dietary NE treatments were fed to pigs using five dietary phases (dietary programs were formulated according to standardized ileal digestible lysine requirements of Improvest males or PC males) to provide an average of 2,212 kcal/kg (low NE), 2,337 kcal/kg (medium NE), or 2,462 kcal/kg (high NE). The experiment was designed and analyzed as a 2 × 3 factorial with main effects of Improvest management and NE. For the overall study period, there were no significant interactions between Improvest management and NE (P ≥ 0.19) for average daily feed intake (ADFI), average daily gain (ADG), or gain:feed (G:F). There were also no significant interactions between Improvest management and NE (P ≥ 0.06) for carcass characteristics. Improvest males consumed less feed (5.3% lower ADFI; P < 0.01), grew faster (5.1% greater ADG; P < 0.01), and were more efficient (11.2% greater G:F; P < 0.01) compared with PC males. Hot carcass weight (HCW) did not differ (P = 0.16) between Improvest males and PC males (attributed to 1.6 percentage unit lower dressing percentage for Improvest males; P < 0.01); however, Improvest males were leaner (0.9 mm less backfat and 0.65% greater predicted lean yield; P < 0.01) compared with PC males. For the overall study period, pigs fed low NE and medium NE diets consumed 7.5% and 4.6% more feed (P < 0.01) than pigs fed high NE diets, respectively, and pigs fed low NE diets grew 1.7% slower (P < 0.02) than pigs fed medium NE and high NE diets. This resulted in pigs fed low NE diets having 4.4% lower G:F compared with pigs fed medium NE and 8.6% lower G:F compared with pigs fed high NE diets (P < 0.01). Pigs fed low NE had 3.0 kg lighter (P < 0.01) HCW compared with medium NE, while high NE had intermediate HCW that did not differ from the other two treatments. Overall, typical Improvest response levels for live performance and carcass characteristics when compared with PC males were achieved for each of the NE treatments evaluated in this study.
PubDate: Fri, 01 Mar 2024 00:00:00 GMT
DOI: 10.1093/tas/txae027
Issue No: Vol. 8 (2024)
- The effects of dietary net energy on grow-finish performance and carcass
characteristics of market gilts managed with immunological suppression of
ovarian function and estrus (Improvest)
First page: txae026
Abstract: AbstractThe objective was to determine the effects of net energy (NE) during the grow-finish period on live performance and carcass characteristics of market gilts managed with immunological suppression of ovarian function and estrus (Improvest®; IMP) compared with market gilts not managed with Improvest (CON). The 104-d study began when 1,008 gilts (11 wk old; average starting weight of 30.8 kg) were allocated by weight to 48 pens with 21 gilts/pen. Half of the pens were randomly selected to be managed with Improvest while the other half of the pens were not managed with Improvest. Three dietary programs differing in their NE were formulated over five dietary phases (according to standardized ileal digestible lysine requirements) to provide an average of 2,218 kcal/kg (low NE), 2,343 kcal/kg (medium NE), or 2,468 kcal/kg (high NE). The experiment was designed as a 2 × 3 factorial with main effects of Improvest management and NE. For the overall study period, there were no significant interactions (P ≥ 0.20) for average daily feed intake (ADFI), average daily gain (ADG), or Gain:Feed (G:F). There were also no significant interactions between Improvest management and NE (P ≥ 0.30) for carcass characteristics. However, IMP gilts consumed more feed (6.8% greater ADFI; P < 0.01), grew faster (5.0% greater ADG; P < 0.01), were less efficient (1.8% lower G:F; P < 0.01), heavier (3.5 kg hot carcass weight; P < 0.01), and fatter (1.9 mm greater backfat thickness and 1.26% less predicted lean carcass yield; P < 0.01). No difference (P = 0.21) in carcass dressing percentage between IMP and CON gilts was reported. For the overall study period, gilts fed low NE and medium NE diets consumed more feed compared with gilts fed high NE diets (6.8% more ADFI for low NE and 5.7% more for medium NE; P < 0.01), and gilts fed low NE diets grew 2.5% slower (P < 0.01) than gilts fed medium NE diets, while gilts fed high NE diets were intermediate and not different from the other NE treatments. This resulted in gilts fed Low NE diets being the least efficient (3.8% lower G:F than medium NE and 7.1% lower G:F than High NE; P < 0.01). Overall, these data indicate that typical Improvest response levels were sustained at each of the NE treatments evaluated in this study as there were no significant interactions for Improvest management and NE; however, consideration should still be provided to the known production impacts of low NE diets.
PubDate: Fri, 01 Mar 2024 00:00:00 GMT
DOI: 10.1093/tas/txae026
Issue No: Vol. 8 (2024)
- Almond hulls and shells as an alternative fiber source in limit-fed
growing beef cattle diets
First page: txae025
Abstract: AbstractAlmond hulls and shells are a by-product of almond production that can be incorporated as a feed ingredient in beef cattle diets. Three experiments were conducted to determine the effects of hammermill screen size on almond hull and shell bulk density and inclusion of ground or non-ground almond hulls and shells in limit-fed growing diets on growth performance, diet digestibility, and ruminal fermentation characteristics of beef cattle. In experiment 1, almond hulls and shells were ground with a laboratory-scale hammermill using no screen, a 11.1-mm screen, a 19.1-mm screen, or a 25.4-mm screen. Each screen-size treatment was ground at three separate time points (n= 3 replications/treatment). Grinding almond hulls and shells with no screen increased bulk density by 111% and minimized proportions of fine particles; therefore, almond hulls and shells ground using no screen were included as a treatment in the following experiments. In experiment 2, 364 steers (initial body weight [BW]: 257± 20.7 kg) were blocked by truckload (n = 4), stratified by BW, and assigned to pen within block. Pens were randomly assigned to 1 of 4 experimental diets (n= 10 pens/treatment). The control diet (CON) contained (DM basis) 39.5% dry-rolled corn, 7.5% supplement, 40% wet-corn gluten feed, and 13% prairie hay. Non-ground (13AH) or ground (13GAH) almond hulls and shells replaced prairie hay and were fed at 13% of diet DM or non-ground almond hulls and shells were fed at 26% of diet DM and replaced 13% prairie hay and 13% dry-rolled corn (26AH). Diets were limit-fed at 2.2% of BW daily (DM basis) for 56 d. Overall average daily gains (ADG) were greater (P ≤ 0.05) for CON, 13AH, and 13GAH compared with 26AH. In addition, ADG from days 14 to 56 were greater (P= 0.03) for 13GAH and tended to be greater (P = 0.09) for 13AH compared with CON. Experiment 3 was a 4 × 4 replicated Latin square in which 8 ruminally cannulated heifers (initial BW = 378 ± 44.0 kg) were fed diets from experiment 2. Apparent dry matter digestibility did not differ (P = 0.21) among treatments. Total ruminal volatile fatty acid concentrations were greater (P ≤ 0.03) for 13GAH and 13AH compared with 26AH and tended (P = 0.06) to be greater for 13GAH compared with CON. Overall, almond hulls and shells can be utilized as an alternative to prairie hay in limit-fed growing diets without negatively influencing rates of gain or diet digestibility.
PubDate: Thu, 29 Feb 2024 00:00:00 GMT
DOI: 10.1093/tas/txae025
Issue No: Vol. 8 (2024)
- The effects of genotype-by-environment interactions on body condition
score across three winter supplemental feed environments in a composite
beef cattle breed in Montana
First page: txae024
Abstract: AbstractCattle operations in the Northern Great Plains region of the United States face extreme cold weather conditions and require nutritional supplementation over the winter season in order for animals to maintain body condition. In cow–calf operations, body condition scores (BCS) measured at calving and breeding have been shown to be associated with several economically important health and fertility traits, so maintenance of BCS is both an animal welfare and economic concern. A low-to-medium heritability has been found for BCS when measured across various production stages, indicating a large environmental influence but sufficient genetic basis for selection. The present study evaluated BCS measured prior to calving (late winter) and breeding (early summer) under three winter supplementation environments in a multitrait linear mixed model. Traits were discretized by winter supplementation and genetic correlations between environments were considered a reflection of evidence for genotype-by-environment interactions between BCS and diet. Winter supplementation treatments were fed October through April and varied by range access and protein content: 1) feedlot environment with approximately 15% crude protein (CP) corn/silage diet, 2) native rangeland access with 1.8 kg of an 18% CP pellet supplement, and 3) native rangeland access with a self-fed 50% CP and mineral supplement. A total of 2,988 and 2,353 records were collected across multiple parities on 1,010 and 800 individuals for prebreeding and precalving BCS, respectively. Heifers and cows came from a composite beef cattle breed developed and maintained by the USDA Fort Keogh Livestock and Range Research Laboratory near Miles City, Montana. Genetic correlations between treatments 1 and 2, 1 and 3, and 2 and 3 were 0.98, 0.78, and 0.65 and 1.00, 0.98, and 0.99 for precalving and prebreeding BCS, respectively. This provides moderate evidence of genotype-by-environment interactions for precalving BCS under treatment 3 relative to treatments 1 and 2, but no evidence for genotype-by-environment interactions for prebreeding BCS. Treatment 3 differed substantially in CP content relative to treatments 1 and 2, indicating that some animals differ in their ability to maintain BCS up to spring calving across a protein gradient. These results indicate the potential for selection of animals with increased resilience under cold weather conditions and high protein, restricted energy diets to maintain BCS.
PubDate: Thu, 29 Feb 2024 00:00:00 GMT
DOI: 10.1093/tas/txae024
Issue No: Vol. 8 (2024)
- Interaction of Sweet Bran inclusion and corn processing method in beef
finishing diets
First page: txae023
Abstract: AbstractThe study objective was to determine the effects of corn processing method and Sweet Bran (Cargill, Blair, NE) inclusion in beef finishing diets on performance and carcass characteristics. Four hundred and eighty crossbred yearling steers (363 ± 15 kg) were assigned to a 2 × 3 factorial arrangement of treatments, consisting of two corn processing methods, steam-flaked corn (SFC) or a high-moisture corn: dry-rolled corn blend (HMC: DRC), and three inclusions of Sweet Bran (0%, 20%, or 40% of diet dry matter). Data were analyzed using the MIXED procedure of SAS as a generalized block design with pen as the experimental unit and block as a fixed effect. Dry matter intake increased linearly as Sweet Bran increased in the diet, regardless of corn processing method (P < 0.01). A corn processing × Sweet Bran interaction (P < 0.01) was observed for feed efficiency (G:F), average daily gain (ADG), and hot carcass weight (HCW).The G:F of steers fed SFC did not change with increasing Sweet Bran concentrations (P = 0.19) and the G:F of SFC-fed steers was 12.4% greater than those fed HMC:DRC without Sweet Bran, but was only 5.3% greater when Sweet Bran was included at 40% (P = 0.04). The ADG of steers increased linearly with increasing concentration of Sweet Bran in both SFC and HMC:DRC-based diets. However, the interaction occurred (P < 0.01) because ADG increased at a greater rate in HMC:DRC-based diets (1.93 to 2.21 kg/d for 0% and 40% Sweet Bran, respectively) compared to SFC-based diets (2.18 to 2.27 kg/d for 0% and 40% Sweet Bran, respectively;). Accordingly, while the ADG of steers fed SFC was 13% greater than steers fed HMC:DRC without Sweet Bran (P < 0.01), there was no difference in ADG due to corn processing method at 40% Sweet Bran (P = 0.30). In SFC-based diets, HCW tended to increase from 446 to 455 kg as Sweet Bran increased (P = 0.06). In HMC: DRC-based diets, HCW linearly increased from 421 to 449 kg (P < 0.01), resulting in similar HCW at 40% Sweet Bran (P = 0.28). These data suggest HMC:DRC-based diets are more competitive with SFC-based diets due to similar gains and more similar feed efficiencies when Sweet Bran is fed.
PubDate: Sat, 24 Feb 2024 00:00:00 GMT
DOI: 10.1093/tas/txae023
Issue No: Vol. 8 (2024)
- Impacts of economic factors influencing net returns of beef feedlot
heifers administered two implant programs and fed for differing
days-on-feed from pooled randomized controlled trials
First page: txae021
Abstract: AbstractThe objective of this research was to evaluate the effects of two implant programs and differing days-on-feed (DOF) on net returns of beef feedlot heifers using sensitivity analyses of key economic factors. Crossbred beef heifers [n = 10,583; initial weight 315 kg (± 20.1 SD)] were enrolled across three trials (one Kansas, two Texas feedlot trials). Heifers were blocked by arrival and randomly allocated to one of six pens, resulting in a total of 144 pens and 24 blocks. Pen was randomly assigned to treatment as a 2 × 3 factorial. Implant programs were: IH + 200—Revalor-IH at initial processing, and a terminal implant after approximately 90 DOF (Revalor-200), or, XH—a single implant at initial processing (Revalor-XH). The DOF treatments were: heifers fed to a standard baseline endpoint (BASE) or heifers fed for an additional + 21 or + 42 d beyond BASE. Pen-level partial budgets were used for economic sensitivity analyses, which varied price points of single pricing components with all other components fixed. Variable components were live-fed cattle prices, base carcass prices (i.e., dressed), Choice-Select spread (CS-spread), and feed and yardage prices (FYP). For each, a Low, Mid-Low, Middle, Mid-High, and High price was chosen. Linear mixed models were fit for statistical analyses (α = 0.05). There were no significant two-way interactions (P-values ≥ 0.14). Regardless of the variable component evaluated, XH heifers had poorer net returns than IH + 200 at all prices (P ≤ 0.04). Selling live, the + 21 and (or) + 42 heifers had lower net returns than BASE at every fed cattle price point (P < 0.01). Selling dressed, the + 21 and (or) + 42 heifers had lower returns than BASE at Low, Mid-Low, and Middle fed cattle base prices (P < 0.01); there were no significant DOF differences at Mid-High, or High prices (P ≥ 0.24). Net returns were lower for + 42 than BASE at all CS-spreads (P ≤ 0.03), while BASE and + 21 did not differ significantly. Longer DOF had lower net returns than BASE when selling live at every FYP (P < 0.01) except at the Low price (P = 0.14). Selling dressed, there was no significant effect of DOF at Low or Mid-Low FYP (P ≥ 0.11); conversely, extended DOF had lower net returns than BASE at Middle, Mid-High, and High FYP (P < 0.01). Overall, there was minimal economic evidence to support extending feedlot heifer DOF beyond the BASE endpoint, and when feeding longer, larger reductions in return were observed when marketing live as opposed to dressed.
PubDate: Tue, 20 Feb 2024 00:00:00 GMT
DOI: 10.1093/tas/txae021
Issue No: Vol. 8 (2024)
- Design thinking for engaged learning in animal science: lessons from five
semesters of a senior capstone course
First page: txae020
Abstract: AbstractThis study presents a design-based research approach involving five iterations (semester) of implementing design thinking for engaged learning (DTEL) in an animal science capstone course. DTEL scaffolds design thinking into 10 stages for collaborative project-based learning to foster skills like problem solving and teamwork. Across five semesters (spring 2021 to spring 2023), student reflections (n = 276) were analyzed to identify aspects that worked well or were challenging. Network analysis visualized relationships (P < 0.05; Q > 0.4) between codes representing strengths, struggles, and alignment with principles from learning theories. Utilizing the relationships between strengths and theory-based principles to address struggles, resulted in changes to the design of the capstone course each iteration (time that the course was taught). The complexity of maps increased over iterations. Initially, struggles were prominent but decreased as responsive design refinements were made. Alignment of student experiences with principles from learning theories grew substantially from the first iteration to the last (theory-related nodes representing 11.4% vs. 24.4% in each network map, respectively), with learning theories also occupying more central positions in the last map (iteration five) compared to earlier ones (iterations one through four). These changes suggest student experiences increasingly aligned with principles of cognitive constructivism, social constructivism, constructionism, situated learning, and transformative learning. Design principles derived from the five-iteration study include: (1) allocating most time to hands-on lab work vs. lecture, (2) designating a coordinator faculty, (3) scaffolding for instructors unfamiliar with DTEL, (4) emphasizing consistency in processes over grades, and (5) intentionally developing teamwork skills. The study demonstrates the value of design-based research for iteratively refining and studying learning experiences to foster critical skills for undergraduate students in animal science.
PubDate: Thu, 15 Feb 2024 00:00:00 GMT
DOI: 10.1093/tas/txae020
Issue No: Vol. 8 (2024)
- The influence of virginiamycin on digestion and ruminal parameters under
feedlot conditions
First page: txae019
Abstract: AbstractThis experiment aimed to assess the impact of virginiamycin on in vitro gas production dynamics, rumen kinetics, and nutrient digestibility in beef steers fed a grain-based diet. Nine ruminally cannulated British-crossbred steers (596 ± 49 kg) were assigned to this experiment. Animals were housed in three pens (n = 3/pen) equipped with a Calan gate feed system and water troughs. Pens were enrolled in a 3 × 3 Latin square design containing three periods of 16 d, and a 5-d washout interval between periods. Dietary treatments consisted of virginiamycin (VM) administration at 0 (VM0), 180 (VM180), or 240 mg/d (VM240). During days 15 and 16 of each period, about 600 mL of rumen fluid and urine samples were collected before (0 h), and at 4, 8, 12, and 16 h after the morning feed (0730 hours), rumen inoculum was used to take pH and redox potential measurements immediately after collection using a portable pH and redox meter, and subsamples were taken for volatile fatty acids (VFA) and NH3–N analyses, and urine samples were composited daily and analyzed for creatinine and purine derivatives (PD) content to estimate microbial crude protein flow. During the 4-h post-morning feed rumen collection, rumen inoculum was utilized to perform in vitro gas production measurements. Fecal samples were collected on day 16 of each period to estimate nutrient digestibility using acid detergent insoluble ash as an internal marker. Animals were considered the experimental unit for the statistical analyses, and periods and squares were included as random variables. The total and rate of gas production were similar among treatments (P ≥ 0.17). The second-pool (i.e., fiber) gas production increased linearly as VM inclusion increased (P = 0.01), with VM240 being greater compared to VM180 and VM0 (7.84, 6.94, and 6.89 mL, respectively). Ruminal pH linearly increased as VM increased, with VM240 being greater than VM0 and VM180 intermediate (5.90, 5.82, and 5.86, respectively; P = 0.03). The VFA concentrations did not differ (P ≥ 0.13), but the acetate-to-propionate ratio was the highest in VM240 (P = 0.005). Branched-chain VFA increased (P ≤ 0.03) while lactate concentrations decreased (P = 0.005) linearly with VM. The ruminal NH3–N concentration was the lowest in the VM0 (P = 0.006). The estimated absorbed PD, purine derivative to creatinine index, and microbial N flow increased linearly with VM (P ≤ 0.07). The provision of VM influenced rumen dynamics in a dose-dependent manner.
PubDate: Wed, 14 Feb 2024 00:00:00 GMT
DOI: 10.1093/tas/txae019
Issue No: Vol. 8 (2024)
- Influence of particle size and origin of field peas on apparent ileal
digestibility of starch and amino acids and standardized ileal
digestibility of amino acids when fed to growing pigs
First page: txae008
Abstract: AbstractThe objective was to test the hypothesis that particle size and origin of field peas influence the apparent ileal digestibility (AID) of starch, crude protein (CP), and amino acids (AA) and the standardized ileal digestibility (SID) of AA. Three sources of field peas were procured. One source was from the United States and two sources were from Canada. The U.S. source and one of the sources from Canada (i.e., Canada 1) were each divided into two batches and ground to achieve a target particle size of 250 or 450 µm, whereas the other source from Canada (i.e., Canada 2) was only ground to a target particle size of 250 µm. Each batch of field peas was included in one diet as the only source of AA. An N-free diet was used to determine the basal endogenous losses of CP and AA. Six barrows (initial weight: 50.5 kg; SD = 3.7) that had a T-cannula installed in the distal ileum were randomly allotted to a 6 × 6 Latin square design with six diets and six 7-d periods. Ileal digesta from pigs were collected for 2 d after 5 d of adaptation. Data were analyzed using a statistical model that included batch of field peas as the fixed effect and animal and period as the random effects. Contrast statements were used to analyze the effects of particle size, origin, and the interaction between particle size and origin. Results indicated that the AID of starch was increased by reducing the particle size in the U.S. source of field peas, but that was not the case for the Canada 1 source (interaction; P < 0.001). Particle size did not influence the AID of CP or AA, but the Canada 2 source of field peas had greater (P < 0.05) AID of Trp, Ala, Cys, Gly, and Tyr than the field peas from the United States. The SID of CP and AA was also not affected by the particle size of field peas. The SID of CP and Trp was greater (P < 0.05), and the SID of His, Ile, and Thr tended (P < 0.10) to be greater in the Canada 2 source compared with the U.S. source, but no differences between the two Canada sources were observed. In conclusion, a few differences in SID of AA between field peas produced in the United States and peas produced in Canada were observed, but there was no effect on SID of AA of reducing the particle size of field peas from 450 to 250 µm, whereas the AID of starch increased by reducing the particle size only in the field peas from the United States.
PubDate: Sat, 10 Feb 2024 00:00:00 GMT
DOI: 10.1093/tas/txae008
Issue No: Vol. 8 (2024)
- Reviewer List 2023
First page: txae004
Abstract: The Section Editors and the Editor-In-Chief of Translational Animal Science like to thank the many scientists who have contributed their time and talents reviewing manuscripts for the journal. Reviewing for the journal is critical to ensuring that the best science is published. The expertise of these individuals is invaluable to the journal, the animal science community and to those that depend on the high-quality science that is published.
PubDate: Sat, 10 Feb 2024 00:00:00 GMT
DOI: 10.1093/tas/txae004
Issue No: Vol. 8 (2024)
- Service-learning outreach to attract high school students to degrees and
careers in agricultural sciences
First page: txae012
Abstract: AbstractGiven projected deficits and a lack of diversity, there is a critical need to recruit and develop the next generation of the agricultural workforce. The objectives of our study were to evaluate if AgCamp, a one day workshop focused on agriculture delivered through a college student-led service-learning platform: (1) increased high school students’ knowledge of agriculture, (2) changed their interests in pursuing degrees and careers in agriculture, and (3) increased their comfort and confidence in communicating with others in agriculture. We hosted high school students at AgCamp and provided them with instruction in animal science, horticulture, and agricultural mechanics. Pre- and post-test survey instruments were developed and distributed at the beginning and end of AgCamp. Data were analyzed with SPSS 26.0 using paired sample t-tests. As a result of attending this outreach initiative, high school students (n = 26) reported having more knowledge of horticulture (P < 0.01) and agricultural mechanics (P < 0.01), but not animal science (P = 0.12), likely due to greater incoming knowledge of this sub-discipline, as reflected on the pre-test value. High school participants were also more interested in pursuing a college degree (P = 0.04) and career (P < 0.01) in agriculture and became more confident approaching other high school students (P < 0.01), college students (P < 0.01), and college faculty (P = 0.01) involved in agriculture. Ultimately, participating in AgCamp stimulated high school students’ knowledge and interest in pursuing agricultural degrees and careers, indicating there is value in offering youth outreach as short-term programming to attract students to agriculture.
PubDate: Sat, 10 Feb 2024 00:00:00 GMT
DOI: 10.1093/tas/txae012
Issue No: Vol. 8 (2024)
- Effect of extrusion on energy and nutrient digestibility of lentil-based
diets containing either supplemental plant or animal protein fed to
growing pigs
First page: txae017
Abstract: AbstractNon-food grade and excess lentil grain production may be included in swine feeds to provide starch and protein and reduce feed cost. Extrusion processing may increase energy and nutrient digestibility of lentil-based diets containing either supplemental plant or animal protein sources. Therefore, the apparent ileal digestibility (AID) of crude protein (CP) and amino acids (AA), apparent total tract digestibility (ATTD) of gross energy (GE), and digestible energy (DE) value of lentil-based diets were assessed in growing pigs. Two diets were formulated to provide 2.4 Mcal net energy (NE)/kg and 4.35 g standardized ileal digestible lysine/Mcal NE: (1) soybean meal (SBM) diet, containing 50% lentil, 31% wheat, and 12.8% SBM; and (2) fish meal (FM) diet, containing 40% lentil, 45% wheat, and 10% FM. Following mixing, each diet batch was divided into two parts: one part remained as mash, whereas the other part was extruded using a single-screw extruder (400 rpm, 250 kg/h). Eight ileal-cannulated barrows (32.3 ± 1.5 kg) were fed the four diets at 2.8 times maintenance DE requirement (110 kcal per kg of body weight0.75) for four 9-d periods in a double 4 × 4 Latin square to achieve 8 observations per diet. Data were analyzed as a 2 × 2 factorial arrangement including protein source, post-mixing processing, and their interaction as fixed effects. The lentil sample contained 32.3% starch, 24.4% CP, 9.3% total dietary fiber, and 1.7 mg/g of trypsin inhibitor activity on as is-basis. Interactions between dietary protein source and post-mixing processing were not observed. Feeding FM diets resulted in greater (P < 0.05) AID of dry matter (DM), GE, and most AA, and ATTD of CP, but lower apparent hindgut fermentation of DM and GE than SBM diets. Extrusion increased (P < 0.05) the ATTD of GE and DE value of diets. The AID of CP and AA was 3.2 and 4.7%-units greater (P < 0.05), respectively, for the extruded than mash diets. In conclusion, feeding FM diets resulted in greater ileal digestibility of DM, GE, and AA than SBM diets. Extrusion increased the AID of CP and most AA, and DE value of lentil-based diets containing either supplemental plant protein or animal-protein, indicating that extrusion can increase the energy and protein value of plant-based diets fed to pigs.
PubDate: Fri, 09 Feb 2024 00:00:00 GMT
DOI: 10.1093/tas/txae017
Issue No: Vol. 8 (2024)
- Effects of electrolyte supplementation on performance and physiological
responses of preconditioning beef calves
First page: txae016
Abstract: AbstractThe objective of this study was to evaluate the effects of electrolyte solution supplementation on the performance and physiological responses of beef calves during a 45-d preconditioning phase. Forty Angus × Hereford steers (230.4 ± 4.8 kg body weight [BW]) were sorted into 20 pens (2 steers/pen) following weaning (day 0). Treatments were randomly assigned to pens: (1) control: access to water only and (2) electrolyte: access to water and electrolyte solution supplementation (10% of total daily water intake) from days 1 to 14. Calf BW and blood samples were collected on days 0, 1, 3, 7, 14, 21, and 44 of the study. Blood samples were analyzed for sodium, potassium, albumin, haptoglobin, ceruloplasmin, and cortisol. All variables were analyzed using the MIXED procedure of SAS. Electrolyte solution consumption was estimated at 0.70 kg/calf daily (SEM ± 0.21). Calves assigned to the Electrolyte treatment had greater water and total liquid intake than control (P < 0.05). No effects of treatment were observed on ADG or BW (P > 0.05). Effects of day (P < 0.004), but not treatment or treatment × day were observed for sodium, potassium, albumin, cortisol, ceruloplasmin, and haptoglobin. Electrolyte solution supplementation during the preconditioning period did not improve performance nor influenced stress-related markers, however improved liquid intake.
PubDate: Fri, 09 Feb 2024 00:00:00 GMT
DOI: 10.1093/tas/txae016
Issue No: Vol. 8 (2024)
- One-shot technology for three-dimensional imaging of large animals:
perspectives for ruminant management
First page: txae018
Abstract: AbstractIn numerous systems of animal production, there is increasing interest in the use of three-dimensional (3D)-imaging technology on farms for its ability to easily and safely measure traits of interest in living animals. With this information, it is possible to evaluate multiple morphological indicators of interest, either directly or indirectly, and follow them through time. Several tools for this purpose were developed, but one of their main weaknesses was their sensitivity to light and animal movement, which limited their potential for large-scale application on farms. To address this, a new device, called Deffilait3D and based on depth camera technology, was developed. In tests on 31 Holstein dairy cows and 13 Holstein heifers, the values generated for most measured indicators were highly repeatable and reproducible, with coefficients of variation lower than 4%. A comparison of measurements obtained from both Deffilait3D and the previous validated system, called Morpho3D, revealed a high degree of similarity for most selected traits, e.g., less than 0.2% variation for animal volume and 1.2% for chest depth, with the highest degree of difference (8%) noted for animal surface area. Previously published equations used to estimate body weight with the Morpho3D device were equally valid using Deffilait3D. This new device was able to record 3D images regardless of the movement of animals and it is affected only by direct daylight. The ongoing step is now to develop methods for automated analysis and extraction from images, which should enable the rapid development of new tools and potentially lead to the large-scale adoption of this type of device on commercial farms.
PubDate: Fri, 09 Feb 2024 00:00:00 GMT
DOI: 10.1093/tas/txae018
Issue No: Vol. 8 (2024)
- Long-term impacts of 48-h water and feed deprivation on blood and
performance responses of grazing Bos indicus Nellore heifers
First page: txae015
Abstract: AbstractThe study investigated the effects of 48-h water and feed deprivation on blood and the performance of grazing Nellore (Bos indicus) heifers. Twenty-four Nellore heifers (initial body weight [BW] = 238 ± 10 kg; age = 16 ± 2 mo), were ranked by initial BW and age and randomly assigned to one of the two treatments: (1) grazing animals with free access to pasture, water, and mineral-mix (CON; n = 12), or (2) the same grazing conditions but deprived of pasture, water, and mineral-mix for 48 h (DPR; n = 12). The paddocks consisted of Urochloa brizantha cv. Marandu, using a continuous and fixed stocking rate. The experiment lasted 225 d, with the first 14 d considered as the adaptation period (days −14 to −1) and the subsequent 211 d as the evaluation period (days 0 to 211). From days 0 to 2, treatments were applied by keeping the DPR heifers in pens and reintegrating them into the experimental area after a 48-h water and feed deprivation. Individual full BW was recorded on days −14, −13, −1, before (day 0) and after (day 2) treatment application, and on days 6, 11, 12, 41, 42, 210, and 211. Blood samples were collected in the morning on days 0, 2, 6, 12, and 211. A treatment effect was detected (P < 0.001) for shrink BW from days 0 to 2, which was greater (P < 0.001) in DPR vs. CON heifers. Subsequently, DPR animals were lighter (P < 0.001) compared with CON heifers by the end of the deprivation period (day 2). From days 4 to 211, DPR was lighter (P < 0.001) compared with CON heifers after treatment application and for the entire experimental period. In the first 10 d after treatment application (days 2 to 12), DPR heifers showed a partial compensatory average daily gain (ADG; P < 0.001) compared with CON heifers, while no significant differences were observed in ADG between the treatments from days 12 to 42 and 42 to 211 (P > 0.420). Overall ADG (days 2 to 211) was greater (P < 0.001) for DPR vs. CON heifers. All serum variables, except AST, were higher (P < 0.001) in DPR than in CON heifers on day 2 after treatment application. Our study demonstrates that grazing Nellore heifers subjected to 48-h water and feed deprivation experienced significant alterations in their blood metabolites and BW immediately after the stressful event. Although the deprived heifers partially compensated for their BW loss in the early days post-deprivation, they remained 12 kg lighter than the non-deprived animals throughout the production cycle.
PubDate: Thu, 01 Feb 2024 00:00:00 GMT
DOI: 10.1093/tas/txae015
Issue No: Vol. 8 (2024)
- Use of methane production data for genetic prediction in beef cattle: A
review
First page: txae014
Abstract: AbstractMethane (CH4) is a greenhouse gas that is produced and emitted from ruminant animals through enteric fermentation. Methane production from cattle has an environmental impact and is an energetic inefficiency. In the beef industry, CH4 production from enteric fermentation impacts all three pillars of sustainability: environmental, social, and economic. A variety of factors influence the quantity of CH4 produced during enteric fermentation, including characteristics of the rumen and feed composition. There are several methodologies available to either quantify or estimate CH4 production from cattle, all with distinct advantages and disadvantages. Methodologies include respiration calorimetry, the sulfur-hexafluoride tracer technique, infrared spectroscopy, prediction models, and the GreenFeed system. Published studies assess the accuracy of the various methodologies and compare estimates from different methods. There are advantages and disadvantages of each technology as they relate to the use of these phenotypes in genetic evaluation systems. Heritability and variance components of CH4 production have been estimated using the different CH4 quantification methods. Agreement in both the amounts of CH4 emitted and heritability estimates of CH4 emissions between various measurement methodologies varies in the literature. Using greenhouse gas traits in selection indices along with relevant output traits could provide producers with a tool to make selection decisions on environmental sustainability while also considering productivity. The objective of this review was to discuss factors that influence CH4 production, methods to quantify CH4 production for genetic evaluation, and genetic parameters of CH4 production in beef cattle.
PubDate: Wed, 31 Jan 2024 00:00:00 GMT
DOI: 10.1093/tas/txae014
Issue No: Vol. 8 (2024)
- Comparative impact of bacitracin and select feed additives in the feeding
program of Lohmann LSL-Lite pullets at the onset of lay through to
31 weeks of age
First page: txae013
Abstract: AbstractThere are limited investigations on the role of feed additives in easing transition of pullets to egg production phase. We investigated the effects of supplementation of bacitracin methylene disalicylate (BMD) and select feed additives (myristic acid [MA], benzoic acid [BA], and Aspergillus niger probiotic [PRO]) in feeding program for pullets from the onset of lay through to 31 weeks of age (woa). Parameters measured included hen-day egg production (HDEP), feed intake (FI), feed conversion ratio (FCR), egg quality characteristics, ceca microbial activity, apparent retention of components, and plasma metabolites. A total of 1,200 Lohmann LSL Lite pullets were procured at 18 woa and placed in enriched cages (30 birds/cage) based on body weight (BW) and allocated to five diets. The diets were a basal diet formulated to meet specifications or basal mixed with either BMD, MA, BA, or PRO. Birds had free access to feed and water throughout the experiment. Between 18 and 20 woa, birds fed BMD ate a similar (P > 0.05) amount of feed to BA birds, but more (P = 0.0003) than birds fed basal, MA, or PRO diets. Basal birds had lower HDEP (P = 0.001) and lighter eggs (P < 0.0001) than birds fed any of the feed additives between 21 and 31 woa. The basal hens had a higher (P = 0.009) abundance of Escherichia coli than birds fed BMD, BA, and PRO diets. Consequently, BMD, BA, and PRO birds had a higher (P = 0.011) Lactobacilli: E. coli ratio (LER) than hens fed the basal diet. Specifically, relative to basal-fed hens, the LER of the BMD, MA, BA, and PRO hens was higher by 37%, 21%, 26%, and 45%, respectively. Moreover, birds fed PRO tended to have a higher concentration of ceca digesta acetic acid (P = 0.072) and a lower concentration of isobutyric acid (P = 0.096). In conclusion, supplementing pullet diets with broad-spectrum antibiotics or feed additives (MA, BA, and PRO) had a positive impact on FI, and egg production linked to modulation of indices of gut health. The results suggested supplementing feed additives in feeding programs for pullets at the onset of lay can bolster productivity outcomes.
PubDate: Thu, 25 Jan 2024 00:00:00 GMT
DOI: 10.1093/tas/txae013
Issue No: Vol. 8 (2024)
- Effects of housing systems and laying phases on external and internal egg
quality characteristics of indigenous guinea fowl hens
First page: txae011
Abstract: AbstractThe study investigated the effect of housing system and laying phases on the internal and external qualities of guinea fowl eggs laid in three different housing systems. The trial involved the use of 117, 34-wk-old guinea fowl hens which were assigned to three housing types, which were battery cages, deep litter, and deep litter housing systems with free runs, which had the same dimensions as deep litter houses but with free run and open-air space to allow the birds to have free access to soil and exhibit natural behavior. The laying phases of the birds were partitioned into three (36 to 40, 41 to 45, and 46 to 50 wk of age). The data collected were subjected to analysis of variance (ANOVA) using a 2 × 3 factorial design. The findings demonstrated that both housing type and laying period significantly influenced egg quality parameters, with deep litter housing exhibiting higher egg weight, egg breadth, and shell surface area. Battery cage housing had thicker shells and a higher percentage of shell weight than total egg weight. As the birds aged, most parameters increased, while shell thickness decreased. The interaction between housing type and laying period played a crucial role, with egg weight, breadth, and egg shape index increasing as the birds aged. The shell thickness decreased as the laying period progressed across all housing systems. During the 40 to 45 wk period of lay, they exhibited the highest albumen height, haugh unit, and % yolk weight. The study’s findings highlight how the interaction between the housing system and the laying period impacted the internal quality of guinea fowl eggs.
PubDate: Mon, 22 Jan 2024 00:00:00 GMT
DOI: 10.1093/tas/txae011
Issue No: Vol. 8 (2024)
- Panax notoginseng stems and leaves affect microbial community and function
in cecum of duzang pigs
First page: txad142
Abstract: AbstractPanax notoginseng is a Chinese medicine with a long history in which stems and leaves are the wastes of processing Panax notoginseng and have not been effectively utilized. The effects of diets containing Panax notoginseng stems and leaves on the cecal short-chain fatty acid (SCFA) concentration and microbiome of independent pigs were studied. Diets containing Panax notoginseng stems and leaves did not affect the concentration of SCFA in the cecal contents of Duzang pigs but affected the microbial composition and diversity. Firmicutes, Proteobacteria, and Bacteroidetes dominate in the cecal of Duzang pigs. Feeding Duzang pigs with a 10% Panax notoginseng stems and leaves diet increases the abundance of Lactobacillus, Christensenellaceae R-7 group, and Akkermansia in the cecal. We found 14 genera positively associated with acetate, and they were Lactobacillus, Ruminococcaceae UCG 005, Ruminiclostridium 6; Escherichia Shigella and Family XIII AD3011 group showed negative correlations. Solobacterium, Desulfovibrio, and Erysipelatoclostridium were positively associated with propionate. Campylobacter, Clostridium sensu stricto 11, and Angelakisella were positively associated with butyrate. In conclusion, Panax notoginseng stems and leaves could affect the cecal microbial community and functional composition of Duzang pigs. Panax notoginseng stems and leaves reduce the enrichment of lipopolysaccharide biosynthetic pathway of the cecal microbiome, which may have a positive effect on intestinal health. The higher abundance of GH25 family in Duzang pig’s cecal microbiome of fed Panax notoginseng stems and leaves diet. This increase may be the reason for the microbial diversity decrease.
PubDate: Mon, 22 Jan 2024 00:00:00 GMT
DOI: 10.1093/tas/txad142
Issue No: Vol. 8 (2024)
- Postmanufacturing techniques for mitigation of viral pathogens in
porcine-derived feed ingredients: a review
First page: txae009
Abstract: AbstractAfrican swine fever virus (ASFV) is a highly infectious virus known to cause substantial mortality and morbidity in pigs. The transmissibility and severity of disease within pigs, as well as the potentially resultant catastrophic trade ramifications, warrant its status as a foreign animal disease of substantial concern to the United States. The ASFV virus can survive for extended periods of time outside its host, and its greatest concentration is often observed in blood and organs, products that are frequently used as raw materials to manufacture porcine-derived ingredients fed to animals in the United States. Unlike ruminant-based proteins that cannot be fed to ruminant animals, it is permissible to feed porcine-derived ingredients to pigs in the United States. However, the increased threat of ASFV entry into the United States and our evolving understanding of viral transmission by feedstuffs warrant further investigation into this practice. The objectives of this review are to describe the current knowledge of ASFV survival in raw materials used to produce porcine-based ingredients, identify priorities for future research, and summarize potential options for managing risk until additional knowledge can be gained. While limited data is available for ASFV-specific mitigation, the temperatures used in both spray-drying and rendering have proven to effectively reduce viral concentrations of multiple swine viruses below detectable limits. However, some of these procedures may not eliminate the risk of recontamination, which necessitates the need for additional prevention or mitigation measures. Most published research in this area relies on direct inoculation of raw ingredient, not the finished porcine-derived ingredient. Currently, three published studies report ASFV mitigation in either thermally processed conditions (>40 °C) or ingredient quarantine (<40 °C). Virus inactivation, or the reduction of viral concentrations below detectable levels, was observed in the thermally processed study and one of the two ingredient quarantine studies. In conclusion, there is little knowledge to eliminate the risk of recontamination in porcine-derived ingredients; therefore, future research should aim to support and validate the currently available literature for the continued and safe production of porcine-derived ingredients in the event of a foreign animal disease outbreak.
PubDate: Fri, 19 Jan 2024 00:00:00 GMT
DOI: 10.1093/tas/txae009
Issue No: Vol. 8 (2024)
- Effects of feeding an inoculated corn silage with or without a direct-fed
microbial on dry matter intake, milk production, and nutrient
digestibility of high-producing lactating Holstein cows
First page: txae010
Abstract: AbstractThis study evaluated the effects of inoculating corn silage and/or feeding a direct-fed microbial (PRO) on performance and nutrient digestibility of lactating dairy cows. At harvesting, corn silage was treated either with water (culated or not [CON]) or Lactococcus lactis and Lentilactobacillus buchneri (INC; SiloSolve FC) at 1.5 × 105 cfu/g of corn silage. Ten mini silos and one farm-scale silo bunker per treatment were prepared for the laboratory and the lactating dairy cow trial, respectively. Five mini silos per treatment were opened on days 2 or 90 post-ensiling for pH measurement, as well as chemical analysis and aerobic stability, respectively. The farm-scale silo bunkers were opened 77 d post-ensiling for the beginning of the lactating cow trial. Eighty lactating Holstein cows were assigned in a 2 × 2 factorial design to: (1) CON silage without PRO (CON-CON; n = 20), (2) CON silage with PRO at 14 g/head/d (CON-PRO; n = 20), (3) INC silage without PRO (INC-CON; n = 20), and (4) INC silage with PRO at 14 g/head/d (INC-PRO; n = 20). Concurrently with the feeding trial, eight cows per treatment were chosen for nutrient digestibility. The pH of the corn silage was not affected by the silage inoculant (P ≥ 0.29), but INC yielded greater concentration of acetic acid and longer aerobic stability (P < 0.01). Dairy cows fed INC had a lower mean total dry matter intake (DMI), milk protein content, and somatic cell counts vs. CON (P ≤ 0.02). On the other hand, milk and fat- and protein-corrected milk (FPCM) production efficiency, milk urea-N, DM, crude protein, and starch digestibility were greater for INC-fed cows (P ≤ 0.03). Feeding direct-fed microbials (DFM) improved mean body weight, milk yield, and FPCM, as well as milk protein and lactose yield (P ≤ 0.05), but reduced milk fat and protein content (P = 0.02). A silage inoculant × DFM interaction was observed for milk production efficiency, milk protein and lactose content, and somatic cell count (P ≤ 0.05). Dairy cows fed INC-CON had a greater milk production efficiency and milk lactose content (P ≤ 0.04), but INC-PRO had lower milk protein content and SCC (P ≤ 0.03). In summary, inoculating L. lactis and L. buchneri increased acetic acid content and aerobic stability of corn silage, reduced DMI, but improved milk production efficiency and nutrient digestibility of lactating Holstein dairy cows. On the other hand, feeding PRO improved milk, protein, and lactose yield. Additionally, combining the feeding of an inoculated corn silage with PRO reduced milk somatic cell count.
PubDate: Sun, 14 Jan 2024 00:00:00 GMT
DOI: 10.1093/tas/txae010
Issue No: Vol. 8 (2024)
- Beefing up communication skills of upper-level animal science students
First page: txae007
Abstract: AbstractAnimal scientists face an increasing need to communicate with the lay public because of the public’s interest in the origin and production of animal-sourced foods. Consumers’ increased interest infers a critical need for effective communication skills among animal science graduates. Effective communication skills are mandatory if students are to explain scientific information and mitigate misinformation about livestock production. The purpose of our study was to investigate the communication styles and communication effectiveness of upper-level animal science students enrolled in a beef cattle production and management course at Texas A&M University across five semesters (N = 241; spring 2018 = 61, summer 2018 = 15, Fall 2018 = 54, spring 2019 = 55, and fall 2019 = 56). Male animal science students (n = 25; 32.9%) preferred assertive and direct communication (a driver communication style) and female students (n = 32; 19.4%) preferred collaborative and accommodating communication (an amiable communication style). Students were moderately experienced with beef cattle production (M = 3.09, SD = 1.07) before enrolling in the course; however, former beef cattle experiences did not influence their preferred communication style [F(10, 230) = 0.36, P = 0.96]. Researchers also observed students’ communication skills during an end-of-semester beef cattle production and management project presentation and identified strengths and weaknesses. Students demonstrated strong, in-depth animal industry knowledge, an ability to connect beef production techniques to management success, and critical thinking skills when answering questions. Oral communication skills warranting improvement included integrating visual aids and/or visual slides to support findings, using improved stage presence and confidence, and sharing responsibilities when presenting as a team. Finally, completion of a supplemental communication training module, intended to develop oral communication skills, significantly improved [F(1, 55) = 4.16, P = 0.046] students’ beef cattle production and management project presentation scores. As students become aware of their communication preferences and tendencies, they become equipped to adjust their communication practices and techniques when needed. Through this study, we gained insight into students’ communication tendencies and skills, which can be used to provide curricular recommendations and enhance students’ workforce readiness.
PubDate: Fri, 12 Jan 2024 00:00:00 GMT
DOI: 10.1093/tas/txae007
Issue No: Vol. 8 (2024)
- Red chili powder dietary supplementation regularized the performance,
hematobiochemical indices, oxidative status, and
8-hydroxy-2’-deoxyguanosine of aflatoxin B1 exposed broiler chickens
First page: txae006
Abstract: AbstractThe effects of red chili powder dietary supplementation on the performance, hematobiochemical indices, oxidative status, and DNA damage in broiler chickens fed aflatoxin B1 (AFB1) contaminated diets were studied. Two hundred and forty Cobb 500 breed day-old broiler chicks were randomly distributed into control group (CONT), 0.5 mg/kg AFB1-exposed group (AFTB), 0.5 g/kg red chili pericarp powder supplementation alongside the 0.5 mg/kg AFB1 exposed group (RCPA), and 0.5 g/kg red chili seed powder supplementation alongside the 0.5 mg/kg AFB1 exposed group (RCSA). The red chili supplementation, in both pericarp powder and seed powder, positively influenced broiler performance by improving (P < 0.05) weight gain, feed intake, and feed conversion ratio, with a reduction in mortality rates compared to the AFTB group. Hematological indices showed that AFB1 exposure decreased (P < 0.05) the red blood cell count, packed cell volume, and hemoglobin (Hb) concentration, but the red chili supplementation mitigated these reductions. Additionally, total white blood cell counts were maintained (P > 0.05) in red chili-supplemented groups compared to CONT. Red chili supplementation increased (P < 0.05) the total protein and globulin concentrations and reduced (P < 0.05) liver enzyme levels compared to the AFTB group. The oxidative enzyme levels in RCPA and RCSA were similar (P > 0.05) to CONT groups. The red chili supplementations counteracted DNA damage, as reflected by similar (P > 0.05) 8-hydroxy-2’-deoxyguanosine levels recorded in RCPA, RCSA, and CONT groups levels. These findings suggest that 0.5 g/kg red chili supplementation has the potential to ameliorate the adverse effects of AFB1 exposure on broiler chickens, improving their performance and health.
PubDate: Thu, 11 Jan 2024 00:00:00 GMT
DOI: 10.1093/tas/txae006
Issue No: Vol. 8 (2024)
- Influence of metabolizable protein and methionine supplementation on
growth-performance of Holstein steer calves during the initial 112-d
feedlot growing phase
First page: txae003
Abstract: AbstractThe objective was to examine the effects of metabolizable protein (MP) and ruminal-protected methionine supplementation on growth performance of Holstein steer calves during the initial feedlot growing phase (112 d). One hundred eighty Holstein steer calves (122 ± 7 kg) were blocked by weight and assigned to 30 pens (6 steers per pen). Five treatments were applied: 1) control, a diet based on steam-flaked corn containing urea and dry distillers grains plus solubles as supplemental N sources with no amino acid addition; 2) control diet plus blood meal supplementation; 3) diet from treatment 2, with 0.064% Smartamine M (70% methionine; Adisseo, Alpharetta, GA) supplementation; 4) diet from treatment 2 with 0.096% Smartamine M supplementation; 5) diet from treatment 2 with 0.128% Smartamine M supplementation. All diets were formulated to exceed the estimated MP requirements. The estimated metabolizable lysine, as well as methionine, was deficient in the control diet. Blood meal was added to the control diet to meet estimated lysine requirements (diet 2), the other diets had increasing concentrations of supplemental methionine. Supplemental MP enhanced (10%, P < 0.02) interim and overall 112-d average daily gain (ADG). Additional effects of supplemental methionine on ADG were not appreciable (P > 0.10). Supplemental MP did not affect (P > 0.10) dry matter intake (DMI) during the first 56-d period; however, it tended to increase (P = 0.08) DMI during the subsequent 56-d period. Overall, supplemental MP or methionine had no appreciable effect (P > 0.10) on DMI. Supplemental MP improved (P < 0.01) gain efficiency and estimated dietary net energy (NE) values during the initial 56-d period (11 and 7%, respectively) and overall (7 and 4%, respectively). Supplemental MP did not affect (P > 0.10) gain efficiency during the second 56-d period, although it tended to enhance (P = 0.08) estimated dietary NE. Supplemental methionine did not appreciably affect (P > 0.10) gain efficiency or estimated dietary NE. Therefore, adding MP to cover the estimated limiting amino acid supply in diets may enhance the gain efficiency and dietary energetics of growing Holstein calves. However, amino acid addition supplementation beyond the requirements may not produce extra productive performance of steer calves.
PubDate: Mon, 08 Jan 2024 00:00:00 GMT
DOI: 10.1093/tas/txae003
Issue No: Vol. 8 (2024)
- Effects of increasing omega-3 fatty acids on growth performance, immune
response, and mortality in nursery pigs
First page: txae002
Abstract: AbstractThree experiments evaluated omega-3 fatty acids, provided by O3 trial feed, on nursery pig growth performance, mortality, and response to an LPS immune challenge or natural Porcine reproductive and respiratory virus (PRRSV) outbreak. In experiment 1, 350 pigs (241 × 600, DNA; initially 5.8 kg) were used. Pens of pigs were randomly assigned to one of the five dietary treatments containing increasing omega-3 fatty acids (0%, 1%, 2%, 3%, and 4% O3 trial feed) with 14 replications per treatment. On day 25, two pigs per pen were injected intramuscularly with 20 μg Escherichia coli LPS per kg BW and one pig per pen was injected with saline as a control. Body temperature was taken from all three pigs prior to and 2, 4, 6, and 12 h post-LPS challenge. Serum IL-1β and TNF-α concentrations were determined in LPS-challenged pigs 24 h prior and 4 h post-LPS challenge. There was no interaction between treatment and time for change in body temperature (P > 0.10). Overall, increasing the O3 trial feed did not affect (P > 0.10) ADG, ADFI, G:F, IL-1β, or TNF-α. In experiment 2, 1,056 pigs (PIC TR4 × [Fast LW × PIC L02] initially 7.3 kg) were used. Pens of pigs were randomly assigned to one of the four dietary treatments containing increasing omega-3 fatty acids (0%, 0.75%, 1.5%, and 3% O3 trial feed) with 12 replications per treatment. Oral fluids tested negative on days 7 and 14, but then positive for North American PRRSV virus via PCR on days 21, 28, 35, and 42. Overall, increasing O3 trial feed increased (linear, P < 0.001) ADG, ADFI, and G:F and decreased (linear, P = 0.027) total removals and mortality. In experiment 3, 91,140 pigs (DNA 600 × PIC 1050; initially 5.1 kg), originating from PRRSV-positive sow farms, were used across eight nursery sites. Each site contained five barns with two rooms per barn and ~1,100 pigs per room. Rooms of pigs were blocked by nursery site and allocated within sow source to one of the two dietary treatments (control or 3% O3 trial feed) with 40 replications per treatment. Oral fluids from 61 of the 80 rooms tested positive for North American PRRSV virus 1 wk postweaning and 78 of the 80 rooms tested positive 3 wk after weaning. Overall, O3 trial feed did not affect ADG, ADFI, or G:F but increased (P < 0.001) total removals and mortalities. In summary, increasing omega-3 fatty acids, sourced by O3 trial feed, did not improve growth performance or immune response in healthy pigs given an LPS challenge. However, it appears that if omega-3 fatty acids are fed prior to a natural PRRSV break (as in experiment 2), growth performance may be improved, and mortality reduced.
PubDate: Fri, 05 Jan 2024 00:00:00 GMT
DOI: 10.1093/tas/txae002
Issue No: Vol. 8 (2024)
- A corn-fermented protein ingredient can be included in early nursey diets
without compromising pig growth performance and health status
First page: txad149
Abstract: AbstractIn nursery diets, ingredients with high protein content and highly digestible nutrients, such as corn-fermented protein product with added yeast mass (GDDY), can be included as an alternative to common protein sources. This study investigated the dietary inclusion of GDDY as an alternative protein source on growth performance and intestinal health of weaned pigs. A total of 594 weaned pigs (5.7 ± 0.9 kg; 18.5 days of age) were allotted to 36 pens in a randomized incomplete block design. Pens were assigned to one of 4 dietary treatments: CON: a common nursery feeding program; SBM75: CON diet replacing 75% of soybean meal (SBM) with GDDY; FM/ESBM: CON diet without fish meal (FM) and enzyme-treated SBM (ESBM) + GDDY; GDDY50: CON diet replacing 50% of SBM, FM, and ESBM with GDDY. Experimental diets were formulated to meet nutrient requirements of nursery pigs and provided in meal form through four phases during the nursery period. Pig growth performance was assessed on days 7, 14, 21, 28, 42, and 53. Pen fecal score was assessed daily from days 0 to 14, and 3 times per week from days 15 to 35. Intestinal health was assessed based on plasma immunoglobulin A (IgA) concentration and the differential sugar absorption test. The total tract digestibility of dry matter (DM), crude protein (CP), gross energy (GE), and phosphorus was also evaluated. From days 0 to 7 and days 7 to 14, dietary treatment had no effect (P > 0.05) on BW, ADG, and ADFI. For the rest of the experimental period, ADG and ADFI were greater (P < 0.05) in pigs fed CON in comparison with those fed SBM75 and GDDY50 and did not differ from pigs fed FM/ESBM. Pigs fed GDDY50 tended (P = 0.082) to have greater serum IgA concentration on day 20 when compared with SBM75 and FM/ESBM pigs. There were no differences among dietary treatments for DM, CP, and GE digestibility. Phosphorus digestibility was higher in FM/ESBM (P < 0.05) compared with SBM75 and GDDY50. These results supported the hypothesis that GDDY can be incorporated in nursery pig diets during the first couple weeks after weaning without affecting growth performance. However, in the late nursery period, inclusion levels starting at 14% can compromise performance.
PubDate: Fri, 05 Jan 2024 00:00:00 GMT
DOI: 10.1093/tas/txad149
Issue No: Vol. 8 (2024)
- Predicting feed intake in confined beef cows
First page: txae001
Abstract: AbstractSix existing equations (three for nonlactating and three for lactating; NRC, 1987, Predicting feed intake of food-producing animals. Washington, DC: The National Academies Press, National Academy of Science; doi: 10.17226/950; NRC, 1996, Nutrient requirements of beef cattle, 7th Revised Edition: Update 1996. Washington, DC: The National Academies Press; doi: 10.17226/9791; Hibberd and Thrift, 1992. Supplementation of forage-based diets. J. Anim. Sci. 70:181. [Abstr]) were evaluated for predicting feed intake in beef cows. Each of the previously published equations are sensitive to cow-shrunk BW and feed energy concentration. Adjustments in feed intake prediction are provided for level of milk yield in NRC (1987. Predicting feed intake of food-producing animals. Washington, DC: The National Academies Press, National Academy of Science; doi: 10.17226/950) and NRC (1996 Nutrient requirements of beef cattle, 7th Revised Edition: Update 1996. Washington, DC: The National Academies Press; doi: 10.17226/9791) equations. The equation published in 1996 used data generated between 1979 and 1993. Our objectives were to validate the accuracy of the published equations using more recent data and to propose alternative prediction models. Criteria for inclusion in the evaluation dataset included projects conducted or published since 2002, direct measurement of feed intake, adequate protein supply, and pen feeding (no metabolism crate data). After removing outliers, the dataset included 53 treatment means for nonlactating cows and 32 treatment means for lactating cows. Means for the nonlactating dataset were dry matter intake (DMI) = 13.2 ± 2.9 kg/d, shrunk body weight (SBW) = 578 ± 83.9 kg, body condition score = 5.7 ± 0.73, and Mcal net energy for maintenance (NEm)/kg of feed = 1.27 ± 0.15 Mcal/kg. Means for the lactating dataset were DMI = 14.6 ± 2.24 kg/d, SBW = 503 ± 73.4 kg, body condition score = 4.7 ± 0.58, and Mcal NEm/kg feed = 1.22 ± 0.16. Simple linear regression was used to determine slope, intercept, and bias when observed DMI (y) was regressed against predicted DMI (x). The NRC (1996. Nutrient requirements of beef cattle, 7th Revised Edition: Update 1996. Washington, DC: The National Academies Press; doi: 10.17226/9791) nonlactating equation underestimated feed intake in diets moderate to high in energy density with intercept differing from 0 and slope differing from one (P ≤ 0.01). Average deviation from observed values was 2.4 kg/d. Similarly, when the NRC (1996. Nutrient requirements of beef cattle, 7th Revised Edition: Update 1996. Washington, DC: The National Academies Press; doi: 10.17226/9791) equation was used to predict DMI in lactating cows, the slope differed from one (P < 0.01) with average deviation from observed values of 3.0 kg/d. New models were developed by pooling the two datasets and including a categorical variable for stage of production (0 = nonlactating and 1 = lactating). Continuous variables included study-average SBW0.75 and diet NEm, Mcal/kg. The best-fit empirical model accounted for 68% of the variation in daily feed intake with standard error of the estimate Sy root mean squared error = 1.31. The proposed equation needs to be validated with independent data.
PubDate: Thu, 04 Jan 2024 00:00:00 GMT
DOI: 10.17226/950; nrc 1996 nutrient requirements of beef cattle 7th revised edition: update 1996. washin
Issue No: Vol. 8 (2024)
- Benchmarking current preslaughter management factors, welfare indicators,
and meat quality outcomes at commercial fed cattle processing facilities
in the United States
First page: txad150
Abstract: AbstractPreslaughter management factors and their impacts on cattle welfare and meat quality are well documented in current literature. However, certain management factors related to transportation and lairage are underrepresented. Benchmarking preslaughter management factors that can impact welfare and meat quality outcomes will allow the industry to identify areas for improvement. The objective of the current study was to benchmark preslaughter management factors for a nationwide sample of commercial fed cattle processing facilities. Five processing facilities in the West, Midwest, and Southwest regions of the United States were sampled from March 2021 to July 2022. Data were collected on a total of n = 637 slaughter lots representing n = 87,220 head of cattle. Variables of interest included general cattle characteristics, distance traveled to the plant, truck wait times to unload, environmental conditions, lairage density, and lairage duration. Additionally, mobility was scored using a four-point locomotion scale (one being normal, not lame, and four being extremely reluctant to move). Carcasses were also observed for bruising using the following scale: no bruises, bruises smaller or larger than a deck of cards, and having multiple bruises. Descriptive statistics were performed on the data at the lot and individual animal level. On average, cattle traveled 155.8 ± 209.6 km (mean ± SD) from the feedlot to the processing facility and waited 30.3 ± 39.7 min to unload. Once in lairage pens, cattle were held for 200.7 ± 195.0 min. The mean lairage stocking density was 3.1 ± 2.0 m2 per head. A majority of the cattle scored a mobility score of 1 (n = 77,645, 91.8%), 7.8% (n = 6,125) were scored as a two and the remaining less than one percent of cattle were scored as either a 3 or 4 (n = 265). Carcasses with bruises less than or equal to the size of a deck of cards (n = 22,672, 27.1%) were less frequent than bruises measuring greater than the size of a deck of cards (n = 34,427, 42.6%). Of carcasses that were bruised, 65.2% (n = 39,856) had multiple bruises of varying size. This baseline data on preslaughter management factors identifies opportunities for improvement in wait times, lairage densities, and factors that cause bruising. Future studies should explore the relationships between these factors and their impacts on welfare and meat quality, report the economic value of these outcomes, and explore industry acceptability and adoptability of optimal preslaughter management practices.
PubDate: Wed, 03 Jan 2024 00:00:00 GMT
DOI: 10.1093/tas/txad150
Issue No: Vol. 8 (2024)
- Copper metabolism and its implications for canine nutrition
First page: txad147
Abstract: AbstractCanine copper nutrition has received increased attention due to recent reports of apparent copper-associated hepatitis in the USA and European Union. In order to properly address the need to modify the U.S. National Research Council and Association of American Feed Control Officials canine copper recommendations that will have implications for all dogs, it is important to understand the complexities of copper metabolism, confounding variables affecting copper status, and the available research on this topic in dogs. Recent trends in consumer preference for dog diets, supplements, and functional treats introduce another layer of complexity, as most ingredients used in these formulations provide vastly different proportions of essential nutrients, thus resulting in great variation in nutrient profiles available to the animal. Although controlled research addressing copper metabolism in dogs is limited, there are lessons to be learned from other monogastric species as well as canine case studies that can provide a base for increasing knowledge to address this issue. Copper metabolism and status in animals is affected by a multitude of factors including absorption, storage, excretion, and nutrient interactions. Given its vital role in many physiological processes, it is important that both nutritional deficiencies and toxicities be avoided. Additionally, another challenge for proper copper nutrition in dogs is the known genetic predispositions of some breeds for copper storage and excretion abnormalities. Therefore, it is imperative that veterinarians, nutritionists, and pet food manufacturers collaborate with the shared goal of providing dog food options that supply the essential nutrients at adequate concentrations to support an active and healthy life. Many questions remain regarding copper metabolism and proper diet formulation for dogs. Future research efforts should focus on discovering reliable, non-invasive methods for evaluating canine copper status, a deeper understanding of genetic predispositions of certain breeds, increased knowledge of copper contributions from various ingredients, and the role of unpredictable physiological stressors on copper metabolism.
PubDate: Wed, 03 Jan 2024 00:00:00 GMT
DOI: 10.1093/tas/txad147
Issue No: Vol. 8 (2024)
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