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Translational Animal Science
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ISSN (Online) 2573-2102
Published by Oxford University Press Homepage  [419 journals]
  • Effects of feeding variable levels of mycotoxins with or without a
           mitigation strategy on growth performance, gut permeability, and oxidative
           biomarkers in nursery pigs

    • Abstract: AbstractThe objectives were to determine how high levels (> 2.5 mg/kg diet) of deoxynivalenol (DON), in conjunction with other naturally occurring mycotoxins (MTX) would impact growth, intestinal integrity, and oxidative status, with or without a mitigation strategy, in nursery pigs. One-hundred and five pigs (5.5 ± 0.52 kg) were randomly allotted to 35 pens and fed dietary treatments for 45 d. Treatments were factorially arranged with the inclusion of MTX being low (L-MTX; < 1 mg/kg diet) or high (H-MTX; > 2.5 mg/kg diet) in combination with no mitigation strategy or the inclusion of a mitigation strategy (Biofix® Plus, BPL; 1.5 mg/kg diet). There was no interaction between MTX level and BPL inclusion on average daily gain (ADG) or gain to feed ratio (GF), (P > 0.10). Compared to pigs fed diets containing L-MTX, feeding pigs diets containing H-MTX decreased ADG and GF (P < 0.05). The addition of BPL had no effect on ADG (P > 0.10), but improved GF (P = 0.09). There was an interaction between MTX and BPL on average daily feed intake (ADFI), where the addition of BPL had no effect on ADFI of pigs fed L-MTX diets but improved ADFI of pigs fed H-MTX diets (P = 0.09). An interaction was detected between MTX and BPL on protein oxidation as measured by plasma protein carbonyls (PC, P = 0.01), where the inclusion of BPL decreased plasma PC in pigs fed H-MTX diets to a greater extent than pigs fed the L-MTX diets. There was no interaction between MTX and BPL, or an effect of MTX or BPL on DNA damage as measured by 8-hydroxy-2ʹdexoxyguanosine (P > 0.10). There was no interaction between MTX and BPL, or a BPL effect on lipid damage as measured by thiobarbituic acid reactive substances (TBARS, P > 0.10), but pigs fed diets containing H-MTX exhibited lower concentrations of plasma TBARS (P = 0.07) compared to pigs fed L-MTX diets. There was no interaction between MTX and BPL, or an effect of MTX or BPL on plasma lactulose and mannitol ratio as a measure of intestinal permeability (P > 0.10). In conclusion, feeding H-MTX decreased ADG and GF, decreased plasma TBARS, but did not affect plasma 8-hydroxy-2ʹdexoxyguanosine or plasma LM ratio. The inclusion of a mitigation strategy improved ADFI when pigs were fed H-MTX diets and improved GF regardless of MTX level. Addition of a mitigation strategy also reduced plasma protein damage but did not affect indicators of DNA or lipid damage or affect gastrointestinal integrity.
      PubDate: Tue, 13 Sep 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac126
      Issue No: Vol. 6, No. 3 (2022)
       
  • Impacts of postpartum length at the initiation of the fixed-time
           artificial insemination protocol on pregnancy rates of Bos indicus beef
           cows

    • Abstract: AbstractThe shortest interval between calving and initiation of fixed-time artificial insemination (FTAI) protocols recommended in Brazilian cow–calf systems is 30 d, based on research that characterized uterine involution and incidence of uterine disorders in Bos taurus females. Prevalence of uterine disorders such as subclinical endometritis is limited in Nelore (B. indicus) cows as early as 28 d after calving. We hypothesized that Nelore cows can receive an FTAI protocol as early as 20 d postpartum (DPP) and still experience satisfactory reproductive results. This study evaluated pregnancy rates in 5,258 Nelore cows (n = 1,703 primiparous and 3,555 multiparous) according to DPP at the initiation of the FTAI protocol. Cow body condition score (BCS) was recorded at FTAI, and pregnancy diagnosis was performed ~30 d after FTAI. Cows were ranked within parity by DPP at the initiation of the FTAI protocol and classified according to 5-d intervals (e.g., ≤15 DPP, 16 to 20 DPP, 21 to 26 DPP, until cows with ≥76 DPP). Data were analyzed within parity, using cow as experimental unit and orthogonal polynomial contrasts (linear, quadratic, or cubic) generated using the mean DPP of each DPP class. In both parities, cow BCS at FTAI decreased linearly (P ≤ 0.01) with the advance of DPP (e.g., 4.79, 4.00, and 3.73 in primiparous, and 4.95, 3.70, and 3.23 in multiparous cows classified as ≤15 DPP, 36 to 40 DPP, ≥76 DPP, respectively). The pregnancy rate to FTAI was affected quadratically (P < 0.01) by DPP for both parities. In primiparous cows, the pregnancy rate increased until 36 to 40 DPP (60%), remained near this level until 51 to 60 DPP, and then decreased with the advance of DPP, whereas cows classified as 21 to 25 DPP expressed satisfactory results (41.5%). In multiparous cows, the pregnancy rate increased until 46 to 50 DPP (70.8%), remained near this level until 56 to 60 DPP, and then decreased with the advance of DPP, whereas cows classified as 21 to 25 DPP also expressed satisfactory results (63.6%). Collectively, primiparous and multiparous Nelore cows evaluated herein experienced optimal pregnancy rates when the FTAI protocol was initiated within 30 to 60 DPP, although reasonable outcomes were observed when the FTAI protocol was initiated as early as 21 DPP. Hence, the interval between calving and initiation of the FTAI protocol can be shortened by 10 d in Nelore females and still yield acceptable pregnancy rates, which can be of great value to cows that calve immediately prior to or during the annual breeding season.
      PubDate: Sat, 10 Sep 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac095
      Issue No: Vol. 6, No. 3 (2022)
       
  • Impact of water flow rate on finishing pig performance

    • Abstract: AbstractA survey of 23 South Dakota pork producers in 2019 reported that 68% of the waterers in finishing barns had water flow rates above the recommended rate of 500–1,000 mL/min. The objective of the two studies was to determine the impact of water flow rate on finishing pig performance in the summer months. Study 1 used a total of 396 pigs in two groups in a 77-day trial (35.0 to 104.3 kg BW) with 6 pigs/pen and 1 cup waterer/pen. Study 2, conducted in a commercial style barn, used a total of 1,227 pigs in an 84-day trial (60.9 to 117.4 kg BW) with 26 pigs/pen and 2 cup waters/pen. Pens were assigned to one of three water flow rates (high, medium, low) based on the 3-hole settings of the water nipples (2.0, 1.0, and 0.8 mm; n = 22 and 16 pens/treatment for Study 1 and 2, respectively). Room temperature, outside temperature and relative humidity were recorded daily for both studies. In Study 1, water disappearance was recorded daily, and individual pen water flow rates were recorded every two weeks. At every diet phase change (26 ± 2.6 days), feed disappearance and individual pig body weights were recorded. Water flow rates averaged 1856 ± 188, 906 ± 214, 508 ± 100 mL/min for high, medium, and low flow settings, respectively. In Study 2, individual pen water flow rate, water disappearance, BW, and feed disappearance were recorded every two weeks. Water flow rates averaged 1115 ± 98, 906 ± 209, and 605 ± 203 mL/min for high, medium, and low flow settings, respectively. In both studies, there were no differences in final BW, cumulative ADG, or G:F. Due to the variability of water flow rate within a setting, data was further analyzed using regression with flow rate as the independent variable. Apart from average daily water disappearance (adj. R2 = 0.87), there was a low relationship between pig performance and water flow rate (adj. R2 < 0.09). The low R2 values associated with pig performance and the high association with water disappearance suggests that water flow rate above current recommendations has little impact on finishing pig performance but does contribute to water wastage and its associated costs.
      PubDate: Thu, 01 Sep 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac125
      Issue No: Vol. 6, No. 3 (2022)
       
  • Evaluation of predictive models to determine total morbidity outcome of
           feedlot cattle based on cohort-level feed delivery data during the first
           15 days on feed

    • Abstract: AbstractChanges in feeding behavior and intake have been used to predict the onset of bovine respiratory disease in individual animals but have not been applied to cohort-level data. Correctly identifying high morbidity cohorts of cattle early in the feeding period could facilitate the administration of interventions to improve health and economic outcomes. The study objective was to determine the ability of feed delivery data from the first 15 days of feed to predict total feeding period morbidity. Data consisted of 518 cohorts (10 feedlots, 56,796 animals) of cattle of varying sex, age, arrival weight, and arrival time of year over a 2-year period. Overall cohort-level morbidity was classified into high (≥15% total morbidity) or low categories with 18.5% of cohorts having high morbidity. Five predictive models (advanced perceptron, decision forest, logistic regression, neural network, and boosted decision tree) were created to predict overall morbidity given cattle characteristics at arrival and feeding characteristics from the first 15 days. The dataset was split into training and testing subsets (75% and 25% of original, respectively), stratified by the outcome of interest. Predictive models were generated in Microsoft Azure using the training set and overall predictive performance was evaluated using the testing set. Performance in the testing set (n = 130) was measured based on final accuracy, sensitivity (Sn, the ability to accurately detect high morbidity cohorts), and specificity (Sp, the ability to accurately detect low morbidity cohorts). The decision forest had the highest Sp (97%) with the greatest ability to accurately identify low morbidity lots (103 of 106 identified correctly), but this model had low Sn (33%). The logistic regression and neural network had similar Sn (both 63%) and Sp (69% and 72%, respectively) with the best ability to correctly identify high morbidity cohorts (15 of 24 correctly identified). Predictor variables with the greatest importance in the predictive models included percent change in feed delivery between days and 4-day moving averages. The most frequent variable with a high level of importance among models was the percent change in feed delivered from d 2 to 3 after arrival. In conclusion, feed delivery data during the first 15 days on feed was a significant predictor of total cohort-level morbidity over the entire feeding period with changes in feed delivery providing important information.
      PubDate: Mon, 29 Aug 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac121
      Issue No: Vol. 6, No. 3 (2022)
       
  • Use of fixed calcium to phosphorus ratios in experimental diets may create
           bias in phytase efficacy responses in swine

    • Abstract: AbstractThe objective of this study was to investigate the effects of two dietary total Ca/P ratios on available P release by phytase, measured using growth performance and bone mineralization with 528 barrows and gilts according to a randomized complete block design. Three were 11 diets in a factorial of 2 by 4 plus 3, including 3 reference diets consisting of 0.25% (control), 0.70%, or 1.15% monocalcium phosphate (MCP) and 8 diets from combining 4 phytase doses (500, 1,000, 2,000, and 3,000 FYT/kg) with 0.25% MCP and 2 dietary Ca/P ratios (1.05 and 1.20). Each diet was fed to 6 pens of 8 pigs. All diets contained 3 g/kg TiO2, and fecal samples were collected from each pen on d 13–15 of trial. At the end of trial, one pig per pen was sacrificed to collect a tibia and urine in the bladder. The results showed that MCP improved growth performance linearly (P < 0.01), whereas both a linear and quadratic response was observed with the addition of phytase. The MCP increased the percent bone ash and weights of bone ash, Ca, and P linearly (P < 0.01). At both Ca/P ratios, increasing supplementation of phytase increased the percent bone ash and weights of bone ash, Ca, and P both linearly and quadratically (P < 0.05). Both MCP and phytase significantly increased digestibility of Ca and P as well as digestible Ca and P in diets and reduced the digestible Ca/P ratio. The dietary Ca/P ratio of 1.20 resulted in poorer feed utilization efficiency, more digestible Ca, greater percent bone ash, Ca, and P and heavier weights of bone Ca and P than the ratio of 1.05 (P < 0.05). The ratio of 1.20 elicited numerically higher available P release values from phytase, with percent bone ash and bone P weight as the response variables, but significantly lower values with gain:feed. The urinary concentration of Ca increased linearly (P < 0.01) with increasing digestible Ca/P ratios whilst urinary concentration of P decreased quadratically (P < 0.01). In conclusion, fixing the same total Ca/total P ratio in diets supplemented with increasing phytase dosing created an imbalance of digestible Ca and P, which could have an adverse effect on bone mineralization and thus compromise the phytase efficacy relative to mineral P.
      PubDate: Mon, 29 Aug 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac124
      Issue No: Vol. 6, No. 3 (2022)
       
  • Impact of supplemented undenatured type II collagen on pain and mobility
           in healthy Labrador Retrievers during an exercise regimen

    • Abstract: AbstractThe aim of this experiment was to evaluate the effect of undenatured type II collagen supplementation on inflammation and pain using gait analysis and industry-accepted pain and mobility questionnaires during an exercise regimen in healthy dogs. Forty healthy Labrador Retrievers (20 male/20 female; range: 5 to 12 yr) were sorted into two groups: undenatured type II collagen group receiving 40 mg UC-II product (10 mg total collagen and ≥3% undenatured type II collagen) and placebo group receiving 40 mg maltodextrin daily by capsule. After 2 wk loading, all dogs began an 11 wk endurance exercise regimen consisting of two weekly runs, starting at 5 km and increasingly incrementally to 8 km, with one final 16 km run. Gait analysis was performed at baseline; before, 24 and 48 h after the first 5 km run; and before, 24 and 48 h after the final 16 km run. Gait analysis was calculated to obtain a Four Rivers Kennel (FRK) Inflammation Index score. Dogs were scored according to the Liverpool Osteoarthritis in Dogs (LOAD) and Canine Brief Pain Inventory (CBPI) assessments at baseline, before and after the first 5 km run, and before and after the final 16 km run. On the LOAD questionnaire, undenatured type II collagen group had improved “how active is the dog” (P = 0.03) and less “stiffness after a lie down” (P = 0.041) compared with placebo at pre 5 km. Undenatured type II collagen appeared to mitigate the development of pain after exercise compared with placebo, as related to the CPBI assessment. Undenatured type II collagen dogs had lower “pain at worst” pre 5 km (P = 0.021), “pain at least” post 5 km (P = 0.015), “pain at average” post 5 km (P = 0.046), and “pain as it is now” post 16 km (P = 0.006) compared with placebo dogs. Undenatured type II collagen was more effective than placebo at mitigating inflammation on gait analysis per the FRK Inflammation Index. Undenatured type II collagen dogs had a 6.42 lower FRK Inflammation Index score at 24 h post 5 km (P = 0.032) and 6.3 lower score at 24 h post 16 km (P = 0.029), indicating the mitigation of inflammation on gait analysis. When considering the change between timepoints, undenatured type II collagen had a lower increase in FRK Inflammation scores compared with placebo for baseline to pre 5 km (P < 0.001), pre 16 km to 24 h post 16 km (P = 0.028), and pre 16 km to 48 h post 16 km (P = 0.027). Undenatured type II collagen supplemented Labrador Retrievers improved pain assessment variables and improved FRK Inflammation Index on gait analysis.
      PubDate: Sat, 27 Aug 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac123
      Issue No: Vol. 6, No. 3 (2022)
       
  • Retained energy in lactating beef cows; effects on maintenance energy
           requirement and voluntary feed intake

    • Abstract: AbstractThe objectives of these experiments were to determine the relationship between maintenance requirements and energy partitioned to maternal tissue or milk production in limit-fed Angus cows and to determine the relationship between retained energy during the lactation period to dry-period voluntary forage intake (VDMI). Twenty-four mature fall-calving Angus cows were used in a 79-d study during late lactation to establish daily metabolizable energy required for maintenance (MEm). Cows were individually fed daily a mixed diet (2.62 Mcal MEl/kg, 18.2% crude protein) to meet energy and protein requirements of 505 kg beef cows producing 8.2 kg milk daily. If cow BW changed by ±9 kg from initial BW, daily feed intake was adjusted to slow BW loss or reduce BW gain. Milk yield and composition were determined on 3 occasions throughout the study. Maintenance was computed as metabolizable energy intake minus retained energy assigned to average daily maternal tissue energy change, average daily milk energy yield, and average daily energy required for pregnancy. After calves were weaned, cows were fed a low-quality grass hay diet (8.2% crude protein, 65% NDF) and VDMI was measured for 21 days. Lactation maintenance energy was 83% the default value recommended by NASEM (2016. Nutrient Requirements of Beef Cattle: Eighth Revised Edition.) for lactating Angus cows. Increasing lactation-period retained energy (decreasing BW loss and increasing milk energy yield) was associated with lower maintenance energy requirements (P < 0.01; R2 = 0.92). Increased residual daily gain during lactation was associated with lower lactation maintenance energy requirements (P = 0.05; R2 = 0.17). Post-weaning VDMI was not related to late-lactation milk energy production, although sensitive to lactation period BCS and BW loss. These results contradict previous reports, suggesting that maintenance requirements increase with increasing milk yield.
      PubDate: Thu, 25 Aug 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac120
      Issue No: Vol. 6, No. 3 (2022)
       
  • Evaluation of feeding ruminal-protected folate and cobalt pectinate on
           growth performance, carcass characteristics and plasma vitamin B12 and
           folate status in finishing beef steers

    • Abstract: AbstractA large pen feedlot study was conducted to evaluate the response of yearling steers fed novel sources of rumen-protected folate (RPFA) and cobalt (cobalt pectinate; Co-PECT) on plasma levels of vitamin B12 and folate, growth performance, and carcass characteristics. A total of 2,100 steers (initial BW = 381 ± 45.2 kg.) were enrolled in the study at the time of randomization with 2,091 steers started on treatment diets following the transition to the finishing diet. A generalized randomized block design with sampling error (GRBD) with two treatments and 15 pen replications per treatment (5 blocks × 6 pens/block; 30 pens total with 70 steers/pen) were evaluated with pen serving as the experimental unit. A control (CON) treatment consisted of the standard finishing diet while the test diet consisted of the standard finishing diet providing 3.0 mg ∙ kg−1 DM of RPFA and 1.0 mg ∙ kg−1 DM total supplemental cobalt with approximately half coming from Co-PECT (TEST). Blood samples were collected from 60 randomly selected steers at study initiation and prior to shipping for plasma B12 and folate measurement. Data were analyzed with the model including fixed effects of treatment, block, and treatment within block interaction. Live growth performance was not affected by treatment; however, carcass-adjusted performance and hot carcass weight were numerically improved by TEST in 3 of the 5 blocks (treatment × within block interaction, P ≤ 0.03) of cattle. Plasma levels for both folic acid and vitamin B12 were extremely low at study initiation and increased over the course of the feeding period. Feeding TEST increased (P < 0.01) plasma B12 levels compared to CON by the completion of the trial; however, mean levels would still be considered marginal. Plasma folate was lower (P < 0.05) in TEST steers at the beginning of the study, with no difference between treatments by the time cattle were shipped. Results suggested that cattle coming into the feedlot may be of low or marginal status in both plasma folate and vitamin B12. While the status of folate and B12 improved in both CON and TEST with days on feed, providing RPFA and Co-PECT further helped improve vitamin B12 status; although, overall levels remained low, which may have affected the overall response to RPFA. Additional research is required to better understand the role of B vitamin supplementation for growing-finishing feedlots and develop methods for assessing the status and improving potential responses.
      PubDate: Wed, 24 Aug 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac116
      Issue No: Vol. 6, No. 3 (2022)
       
  • Influence of high cyclic ambient temperature and water drinker design on
           growth performance and water disappearance of growing-finishing pigs

    • Abstract: AbstractThe objective of this study was to determine effects of room temperature and drinker design on growth and water disappearance of growing-finishing pigs (26.9 ± 3.67 to 130.9 ± 5.10 kg live body weight). A split-plot design was used with a 2 × 2 factorial arrangement of treatments: Room Temperature (RT) [Thermoneutral (TN) vs. High (HI); main plot], Drinker Design (DD; Nipple vs. Cup; sub-plot). A total of 316 pigs were used, housed in 32 pens in 4 rooms (8 pens/room; 7 pens of 10 pigs and 1 pen of 9 pigs). Two rooms were on each RT treatment. Room temperature for the TN treatment was constant throughout each day but decreased from 24°C at the start to 20°C and 18°C on d 14 and 45 of the study period, respectively. For the HI treatment, a single, cyclic RT protocol was used throughout the study (30°C from 08:00 to 19:00 h and 20°C from 20:00 to 07:00 h, with 1-h transition periods). Pens had fully-slatted concrete floors and 1 feeder and drinker (either nipple or cup); floor space was 0.67 m2/pig. Pigs had ad libitum access to standard corn-soybean diets, formulated to meet or exceed NRC (2012) nutrient requirements. Water disappearance was measured using a meter fitted to the water line supplying each drinker. There were no interactions (P > 0.05) between RT and DD treatments. Drinker Design did not affect (P > 0.05) growth performance; water disappearance was 7.3% greater (P ≤ 0.05) for Nipple than Cup drinkers. Compared to the TN treatment, the HI treatment had no effect (P > 0.05) on gain:feed ratio, but resulted in lower (P ≤ 0.05) average daily gain (6.5%) and average daily feed intake (5.5%) and greater (P ≤ 0.05) average daily water disappearance (16.8%). These results suggest that both drinker design and RT can affect water disappearance, and that the high, cyclic RT regime used reduced growth performance of growing-finishing pigs. Further research is needed to determine the contribution of water intake and wastage to treatment differences in water disappearance.
      PubDate: Wed, 24 Aug 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac117
      Issue No: Vol. 6, No. 3 (2022)
       
  • Effects of pelleted versus loose salt-limited protein supplement on
           supplement intake behavior of yearling heifers grazing dryland pastures

    • Abstract: AbstractThe objectives of this study were to evaluate the impacts of supplement form on supplement intake behavior, body weight (BW), and body condition score (BCS) change of yearling heifers grazing dryland pastures during the summer. In each of the two years, Angus crossbred heifers (14 mo of age; year 1, N = 57, BW = 449 ± 3.60 kg; year 2, N = 58, BW = 328 ± 3.57 kg) were used in a 84-d completely randomized design evaluating the following treatments: 1) control, no supplement; 2) salt-limited supplement in pelleted form; and 3) a salt-limited supplement in loose form. Individual supplement intake, and time spent at the feeder were measured throughout the course of the study using a SmartFeed Pro self-feeder system (C-Lock Inc., Rapid City, SD, USA). On days 0, 42, and 84, the heifers were weighed, and body condition scored following a 16-h shrink. Supplementation and form of supplement did not influence (P ≥ 0.62) BW change for yearling heifers within or across study grazing periods. Body condition score was not influenced (P ≥ 0.26) by supplementation and form within the 0 to 42 (period 1) or 42 to 84 (period 2)-d periods but displayed a treatment by year interaction (P < 0.01) for the 84-d summer grazing period. Supplement intake (kg/d and g/kg BW) displayed a treatment × period interaction (P < 0.01). Supplement intake (kg/d) of heifers consuming pelleted supplement was 28% and 31% greater (P ≤ 0.02) than heifers consuming loose supplement in periods 1 and 2, respectively. Supplement intake (g/kg BW) of heifers consuming pelleted supplement was 24% and 32% greater (P ≤ 0.05) than heifers consuming loose supplement in periods 1 and 2, respectively. Overall, across both years, supplement intake in period 1 was less than half (P < 0.01) that of period 2, averaging 0.50 and 1.14 kg/day, respectively. Variation in supplement intake (% CV) was greater (P = 0.03) in period 1 compared to period 2, averaging 119% and 91%, respectively. In addition, variation in supplement intake was greater (P = 0.03) in year 2 than year 1, averaging 122% and 88%. Our results suggest that salt-limited supplements have a high degree of intake variation and pelleting could have a masking effect as indicated by the greater intake and intake rate of supplement with heifers consuming the pelleted supplement.
      PubDate: Tue, 23 Aug 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac115
      Issue No: Vol. 6, No. 3 (2022)
       
  • Comparing net returns in the feedlot: Bos Taurus vs. Bos Indicus
           influenced steers with varying anabolic implant intensity

    • Abstract: AbstractThere are two main beef cattle breed types: Bos Taurus (BT) and Bos Indicus (BI). Past research has demonstrated various expected differences in growth, temperament, feeding behavior, and carcass characteristics between these breed types when administered varying levels of anabolic implant. However, little is known about the differences in expected economic returns between these cattle types. The objective of this research is to simulate and compare the expected net returns of BT, Angus (AN) steers and BI influenced, Santa Gertrudis (SG) steers, with moderate or high intensity levels of implants relative to a control with no implant. The animal performance and carcass data for this economic analysis was provided from a recent feeding experiment of AN and SG influenced steers. In the experiment, sixty steers were stratified by weight and breed in a 2 × 3 factorial design examining the two different breeds: AN (N = 38) or SG influenced (N = 22), and three implant strategies: no implant (N = 20), a moderate intensity implant protocol (d0 implant: Revalor-G, d56 implant: Revalor-IS, d112 implant: Revalor-S; n=20), or a high intensity implant protocol (d0 implant: Revalor-IS, d56 implant: Revalor-S, d112 implant: Revalor-200; N = 20). The steers performance and carcass data were used together with publicly available price and input costs data in the simulation of net returns per animal for each of the treatment groups. Results demonstrated that both moderate and high intensity implanted BT steers have higher expected net return (US$78.70/hd. and US$75.84/hd., respectively) compared to BI moderate and high intensity implanted steers (US$47.03/hd. and $6.98/hd., respectively). Stochastic efficiency analysis with respect to a function demonstrated when certainty equivalent values are constrained to those ≥US$0, only the moderate implanted BT steers would be included in the efficient set.
      PubDate: Sun, 21 Aug 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac111
      Issue No: Vol. 6, No. 3 (2022)
       
  • Frequency of maternal supplementation of energy and protein during late
           gestation modulates preweaning growth of their beef offspring

    • Abstract: AbstractThis study evaluated the effects of decreasing the frequency of dried distillers grains (DDG) supplementation during third trimester of gestation on cow physiology and offspring preweaning growth. At 201 ± 7 d prepartum (day 0 of the study), 120 Brangus crossbred cows were stratified by body weight (BW = 543 ± 53 kg) and body condition score (BCS = 5.47 ± 0.73), and then assigned randomly to 1 of 20 bahiagrass (Paspalum notatum) pastures (six cows and 4.7 ha/pasture). Treatments were randomly assigned to pastures (five pastures/treatment) and consisted of cows offered no DDG supplementation (NOSUP) or precalving supplementation of DDG dry matter at 1 kg/cow daily (7×), 2.33 kg/cow every Monday, Wednesday, and Friday (3×), or 7 kg/cow every Monday (1×) from day 0 to 77. All cows assigned to DDG supplementation received the same total amount of DDG dry matter (77 kg/cow) from day 0 to 77. All cow-calf pairs were managed similarly from day 77 until calf weaning (day 342). Supplementation frequency did not impact (P ≥ 0.16) any forage or cow reproduction data. Cow BCS on days 77, 140, and 342 did not differ among 1×, 3×, and 7× cows (P ≥ 0.29) but all supplemented cows, regardless of supplementation frequency, had greater BCS on days 77, 140, and 342 compared to NOSUP cows (P ≤ 0.04). Cows offered 1× supplementation had greater plasma concentrations of IGF-1 on days 35 and 140 compared to NOSUP, 3× and 7× cows (P ≤ 0.04), whereas 3× and 7× cows had greater plasma concentrations of IGF-1 on day 35 compared to NOSUP cows (P ≤ 0.005). Average plasma concentrations of glucose did not differ among 1×, 3×, and 7× cows (P ≥ 0.44), but all supplemented cows had greater plasma concentrations of glucose compared to NOSUP cows (P ≤ 0.05). Birth BW of the first offspring did not differ between 3× and 7× calves (P = 0.54) but both groups were heavier at birth compared to NOSUP calves (P ≤ 0.05). On day 342, calves born from 7× cows were the heaviest (P ≤ 0.05), whereas calves born from 1× and 3× cows had similar BW (P = 0.97) but both groups were heavier compared to calves born from NOSUP cows (P ≤ 0.05). In summary, decreasing the frequency of DDG supplementation, from daily to one or three times weekly, during third trimester of gestation of beef cows did not impact cow BCS but altered maternal plasma concentrations of IGF-1 and glucose, leading to reduced offspring preweaning growth.
      PubDate: Thu, 18 Aug 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac110
      Issue No: Vol. 6, No. 3 (2022)
       
  • Evaluation of the acid-binding capacity of ingredients and complete diets
           commonly used for weanling pigs

    • Abstract: AbstractSome ingredients bind more acid in the stomach than others which can increase gastric pH in weaned pigs causing decreased protein digestion and allow pathogenic micro-organisms to proliferate. Our objective was to measure acid-binding capacity at a pH of 4 (ABC-4) of common nursery ingredients and determine additivity in diets. Ingredient categories included: cereal grains, vegetable proteins, animal proteins and milk, vitamin premixes and minerals, amino acids, and fiber sources. A 0.5-g sample of each ingredient was suspended in 50 mL of distilled deionized water and titrated with 0.1-N hydrochloric acid. Sample ABC-4 was calculated as the amount of acid in milliequivalents (meq) required to lower 1 kg to a pH of 4. Cereal grains were found to have lower ABC-4 compared to other ingredients. Vegetable proteins had higher ABC-4 with more variation than cereal grains. Soybean meal (SBM) had an ABC-4 of 602 ± 28.2 meq. Soy protein concentrate and enzymatically treated soybean meal (ESBM) had higher ABC-4 compared to SBM while fermented soybean meal (FSBM) was lower. Zinc oxide (ZnO) and calcium carbonate (CaCO3) had the highest ABC-4 among all ingredients with values of 21,863 ± 598.7 and 18,384 ± 769.7 meq, respectively. Following ingredient analysis, a series of diets were analyzed to determine additivity by comparing the differences between calculated and analyzed ABC-4 value. All diets analyzed had lower ABC-4 than calculated values; however, analyzed ABC-4 increased along with calculated values across diets. The first series of diets were arranged in a 2 × 5 factorial consisting of increasing CaCO3 with or without ZnO. There was a ZnO × CaCO3 interaction (P = 0.020) for difference between calculated and analyzed ABC-4. Within the interaction, differences between calculated and analyzed ABC-4 increased (linear, P < 0.001) as CaCO3 increased in diets without ZnO, but not in diets with ZnO. The second series of diets analyzed consisted of different levels of SBM with either FSBM or ESBM included at 5% of the diet. Differences between calculated and analyzed values were not different between treatments (P = 0.640). In conclusion, perfect ABC-4 additivity in diets was not found due to lower analyzed than calculated values; however, analyzed ABC-4 still increased as calculated values increased. This data suggests diet ABC-4 can be adjusted through selection of ingredients but more feeding trials are needed to determine its impact on pig performance.
      PubDate: Wed, 17 Aug 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac104
      Issue No: Vol. 6, No. 3 (2022)
       
  • A preliminary exploration of the impact of experiential learning on animal
           science undergraduates’ perceptions of humane stunning and slaughter

    • Abstract: AbstractIt is essential to educate students about humane slaughter as it is a critical component of livestock production, particularly for animal science students who represent future stakeholders in agriculture. There is limited research about the effects of experiential learning on student comfort in participating in education regarding sensitive, yet important topics in the animal sciences. A survey was developed to investigate how a teaching module using an experiential learning activity to teach undergraduates about the slaughter process affected student perceptions of stunning and slaughter. Students enrolled in an animal science course, in which live animals and carcasses are evaluated, were surveyed before and after a teaching module. The module included a lecture about proper stunning and a laboratory activity in which the students had the opportunity to shoot a captive bolt stunner on both model and carcass heads. Respondents completed a pre-survey, attended the laboratory activity, and completed a post-survey; 29 survey responses were recorded. Most respondents were women (23, 79.3%) between the ages of 18 and 21 years (25, 86.2%) and in their first year of college (11, 37.9%). The majority of respondents (22, 75.9%) reported using the captive bolt stunner to stun the model heads during the laboratory activity. After participating in the module, all students strongly agreed that “stunning” is a critical component of livestock slaughter (29, 100%) and most agreed that “stunning is a humane process that ensures animal welfare during the slaughter process” (25, 86.2%). The majority of respondents strongly agreed that the “humane stunning simulation was beneficial to their learning about livestock slaughter” (21, 72.4%) and “improved their understanding of slaughter” (16, 55.2%). Almost all of the survey respondents either agreed or strongly agreed that “the model heads and captive bolt demonstration made them more comfortable with the slaughter process” (14, 48.3%; 14, 48.3%, respectively). This research suggests that experiential learning opportunities are potentially effective teaching strategies for educating undergraduates about the slaughter process. Future research should focus on practical ways to integrate new teaching methods into existing animal science curricula, as this will be critical for educating students on important topics in livestock production and increasing student comfort with sensitive material.
      PubDate: Mon, 15 Aug 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac108
      Issue No: Vol. 6, No. 3 (2022)
       
  • Effects of adding potassium bicarbonate to diets with high or low
           crystalline lysine to influence dietary cation–anion difference on
           finishing pig growth performance

    • Abstract: AbstractDietary cation–anion difference (DCAD), calculated as Na+ + K+ – Cl− in mEq/kg of the diet, represents the influence that monovalent cations and anions from these minerals have on the acid–base status of the animal. However, the recommended range of DCAD for optimal grow-finish swine performance is variable, which may indicate an interaction between DCAD and other ingredients. The hypothesis for this study was that the addition of potassium bicarbonate (KHCO3) to increase diet DCAD when high levels of l-Lys HCl (>0.35% diet) are used may potentially improve growth performance. A total of 1,944 pigs (PIC L337 × 1050, initially 35.2 ± 0.85 kg) were used in a 120-d study. Pens of pigs were blocked by BW and randomly allotted to 1 of 4 dietary treatments in a randomized complete block design. Treatments were arranged in a 2 × 2 factorial with main effects of KHCO3 (0% or 0.4%), and l-Lys HCl level (low or high). l-Lys HCl was included between 0.13% and 0.21% in low diets, and between 0.36% and 0.43% in high diets. There were 27 pigs per pen and 18 replicates per treatment. Treatment diets were corn-soybean meal-based and formulated in four dietary phases (35–60 kg, 60–85 kg, 85–105 kg, and 105–130 kg). Dietary treatments were formulated such that in each phase the diet containing a low level of l-Lys HCl without KHCO3 and the diet containing a high level of l-Lys HCl with KHCO3 had similar calculated DCAD values (169–232 mEq/kg). Additionally, the diet with a low level of l-Lys HCl with KHCO3 was formulated to have the highest DCAD in each phase (220–281 mEq/kg), while the diet with a high level of l-Lys HCl without KHCO3 was formulated to have the lowest DCAD (118–182 mEq/kg). Overall, there was no evidence (P > 0.10) for a KHCO3 × l-Lys HCl interaction or main effect for final BW or any observed growth response or carcass characteristics. The results of this study suggest that supplementing KHCO3 to finishing pig diets with either high or low levels of l-Lys HCl and the corresponding changes in DCAD values did not impact growth performance or carcass characteristics.
      PubDate: Wed, 03 Aug 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac107
      Issue No: Vol. 6, No. 3 (2022)
       
  • Monensin supplementation during late gestation of beef cows alters
           maternal plasma concentrations of insulin-like growth factors 1 and 2 and
           enhances offspring preweaning growth

    • Abstract: AbstractThis study evaluated the effects of maternal prepartum supplementation of dried distillers grains (DDG), with or without monensin addition, on maternal performance and physiology and offspring preweaning growth. On day 0 (approximately 197 ± 4 d prepartum), 150 multiparous, Brangus crossbred beef cows were ranked by their initial body weight (BW; 524 ± 51 kg) and body condition score (BCS; 5.0 ± 0.63), and then randomly assigned into one of 15 bahiagrass (Paspalum notatum) pastures (10 cows and 8.1 ha/pasture). Maternal treatments were randomly assigned to pastures (5 pastures/treatment) and consisted of no prepartum supplementation of DDG (NOSUP) or supplementation of DDG at 1 kg/cow/d (dry matter basis; DM) added with 0 mg (SUP) or 200 mg/d of monensin (SUPMO) from days 0 to 77. Effects of maternal treatment and maternal treatment × day of the study were not detected (P ≥ 0.63) for any forage data. Cow BCS on day 35 and near calving (day 77) did not differ (P ≥ 0.19) between SUP and SUPMO cows but both groups had greater (P ≤ 0.001) BCS compared with NOSUP cows. Cow BCS at the start of the breeding season (day 142) and on day 168 were the greatest (P < 0.0001) for SUPMO cows, least for NOSUP cows, and intermediate (P ≤ 0.02) for SUP cows. Maternal plasma concentrations of glucose did not differ (P ≥ 0.25) among treatments. Plasma concentrations of insulin-like growth factor 1 (IGF-1) on day 77 were the least for NOSUP cows (P ≤ 0.05) and did not differ (P = 0.66) between SUP and SUPMO cows, whereas plasma concentrations of IGF-2 on days 35 and 77 were greatest (P ≤ 0.05) for SUPMO cows and did not differ (P ≥ 0.60) between NOSUP and SUP cows. Birth BW of first offspring did not differ (P = 0.77) between SUP and SUPMO calves but NOSUP calves were lighter at birth (P ≤ 0.05) compared with SUP and SUPMO calves. Percentage of cows pregnant with a second offspring did not differ (P = 0.72) between SUP and SUPMO cows and were the least for NOSUP cows (P ≤ 0.05). First offspring BW at weaning (day 325) was greatest (P ≤ 0.05) for SUPMO calves, least for NOSUP calves, and intermediate for SUP calves. Therefore, adding monensin into prepartum DDG supplements for Bos indicus-influenced beef cows did not increase cow prepartum BCS but led to greatest offspring preweaning growth, likely by modulating maternal plasma concentrations of IGF-1 and IGF-2 during gestation.
      PubDate: Wed, 03 Aug 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac105
      Issue No: Vol. 6, No. 3 (2022)
       
  • Benchmarking animal handling outcomes on cow-calf operations and
           identifying associated factors

    • Abstract: AbstractThe assessment of animal handling is commonly included in cattle care programs. The guidelines set in the National Cattlemen’s Beef Association Beef Checkoff funded Beef Quality Assurance (BQA) program are often used for assessing handling on feedlot, stocker, and cow-calf operations. There is limited information about animal handling on cow-calf operations. Thus, the objectives of this study were to: (1) quantify handling outcomes on cow-calf operations and compare them to national BQA program thresholds, and (2) investigate factors associated with handling outcomes. Researchers visited 76 operations across the United States to observe the following outcomes, adapted from the BQA program, during the processing of cows or yearling heifers: Prod Use, Miscatch, Vocalization, Jump, Slip/Stumble, Fall and Run. One hundred cows or less (depending on herd size) were observed moving through a restraint system at each operation. Other information specific to the animal type, facilities, and management were also gathered to be explored as potential predictors of handling outcomes. Data were summarized using descriptive statistics on an operation basis and analyzed with multi-predictor ANOVA or Kruskal–Wallis tests to assess the relationship between outcomes and possible explanatory factors. Predictors included in the final analyses were: BQA certification (BQA), animal temperament (TEMP), region (REGION), chute style (CHUTE), and visual contact with humans (VISUAL). The 76 operations were sampled in 24 states (Central, n = 17; East, 30; West, 29), with herd sizes ranging from 10 animals to more than 5,000 animals. A total of 4,804 animals were observed. There were a substantial number of operations exceeding BQA thresholds for Prod Use (34.0%, 26), Miscatch (46.0%, 35), and Fall (31.6%, 24); the averages of these outcomes also exceeded the BQA thresholds (< 10%, 0%, and 2%, respectively). There was an association between Prod Use and several explanatory factors, including SIZE (P = 0.072), TEMP (P = 0.001), VISUAL (P = 0.027), and BQA (P = 0.104). Miscatch, Vocalization, and Fall all had single associated factors (REGION, P = 0.019; REGION, P = 0.002; VISUAL, P = 0.002, respectively). The VISUAL and TEMP factors had an association with the majority of outcomes. The findings suggest an opportunity for improving handling outcomes, which could be achieved through education and training support regarding the importance of animal handling on-farm. Future work should consider additional aspects of facilities and management that could impact cattle handling outcomes.
      PubDate: Mon, 01 Aug 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac106
      Issue No: Vol. 6, No. 3 (2022)
       
  • Beef Quality Assurance national rancher survey: program participation,
           best management practices, and motivations for joining future
           sustainability programs

    • Abstract: AbstractTill date, with over 137,000 certified members, the most successful rancher educational program has been the Beef Quality Assurance (BQA) program. The BQA program was established in the mid-1990’s to improve animal health and welfare with a primary objective to reduce the incidence of injection site lesions by instructing producers to administer injections in the neck only. The present study investigated the drivers of this success to inform future rancher education programs around agricultural sustainability. An online multistate survey was administered to cattle ranchers in collaboration with state cattlemen’s associations to better understand rancher motivations for adopting new practices and to gain insight on current involvement in BQA. In total, the survey consisted of 45 questions and was divided into 3 sections: (1) rancher demographics, (2) BQA participation and current best management practice (BMP) application, and (3) willingness to join new rancher educational programs. Data from 842 respondents are including in this study. Of the survey participants, 70% were currently BQA certified or had been BQA certified at one time, and 30% had never been certified. Ranchers who were BQA certified at any time were less likely to administer injections in areas other than the neck compared to ranchers who were not certified (P < 0.05), demonstrating the effectiveness of the BQA program. More than 80% of survey respondents who joined the BQA program stated they believed the BQA program improved animal health and welfare on their operation (n = 617). Among those who had not joined the BQA program, 40% believed BQA practices did not align with their ranching operation, while 38% had not heard of the BQA program (n = 256). The survey indicated that male ranchers, those with more years ranching, those with a larger percent of income coming from ranching, and ranches with larger total acres grazed were more likely to be BQA certified at any time (P < 0.05). Finally, ranchers who were BQA certified at any time were more likely to state that joining a rancher sustainability program would be beneficial to their operation. In conclusion, not only did the survey provide valuable insight into BQA program adoption but highlighted how BQA pedagogy and program structure may be a suitable framework for creating future rancher sustainability programs.
      PubDate: Mon, 01 Aug 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac094
      Issue No: Vol. 6, No. 3 (2022)
       
  • The effects of varying levels of trace mineral supplementation on
           performance, carcass characteristics, mineral balance, and antibody
           concentrations in feedlot cattle

    • Abstract: AbstractThe objective of this experiment was to determine the effects of increasing trace mineral (TM) supplementation on finishing cattle performance, carcass characteristics, TM balance, and antibody concentrations. Commercial Angus steers (n = 240; body weight, BW = 291 kg ± 27.4) were stratified by arrival BW and source and randomly assigned to 1 of 4 experimental treatments in a randomized complete block design (12 pens/treatment; 5 steers/pen). All steers underwent a TM depletion period for a minimum of 42-d prior to the administration experimental treatments. Treatments included a negative control (CON) in which cattle received no additional TM supplementation or TM supplementation treatments in which cattle received added Co, Cu, I, Mn, Se, or Zn from inorganic TM sources at 2016 Nutrient Requirements of Beef Cattle (NASEM) requirement levels (1X), at 2 times NASEM requirements (2X), or at 4 times NASEM requirements (4X). Selenium was included at 0.1, 0.2, and 0.3 mg/kg for 1X, 2X, and 4X respectively, based on federal law. There was no difference in overall BW, average daily gain (ADG), dry matter intake (DMI), or gain to feed (G:F) due to TM supplementation (CON vs. SUPP P ≥ 0.47). There was no difference in hot carcass weight, rib eye area, fat thickness, dressing percentage, marbling score, or USDA Yield Grade due to TM supplementation (CON vs. SUPP P ≥ 0.30). One steer was chosen at random from each pen to be evaluated for serum and liver TM status and antibody concentrations to common respiratory viruses. There was a treatment × day interaction for serum Co and liver Cu and Se (P < 0.0001). Serum Co was greatest for the 4X treatment from d 28 through harvest. Liver Cu was greatest for the 2X and 4X treatments from d 56 through harvest. Liver Se was greatest for 2X and 4X from d 28 through harvest. Serum Zn was greatest for the 4X treatment (P = 0.02). There was an effect of day on liver Co, Fe, Mn, Mo, and Zn (P ≤ 0.0001) and serum Cu, Mn, Mo, Se, and Zn (P ≤ 0.002). Concentrations for individual TM had different trends over time, however, all reported values were within normal ranges. There was an effect of time on bovine viral diarrhea virus Type 1A, bovine herpesvirus type 1, and bovine parainfluenza 3 virus antibody concentrations (P ≤ 0.0001). Supplementation of TM above NASEM requirements did not affect overall cattle performance, carcass characteristics, or antibody concentrations, but did affect the storage and circulation of certain TM.
      PubDate: Thu, 28 Jul 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac093
      Issue No: Vol. 6, No. 3 (2022)
       
  • Bunk space requirements for growing beef cattle limit-fed a high-energy
           corn and corn co-product diet

    • Abstract: AbstractBunk requirements for optimal growth performance of growing calves limit-fed high-energy corn and corn co-product diets have not been widely evaluated. Three-hundred eighty-five crossbred steers (initial body weight = 215 ± 25 kg) were purchased in Texas, transported to the Kansas State Beef Stocker Unit, and weighed at arrival. Steers were stratified by body weight and randomly assigned to 1 of 28 pens containing 12 to 14 head. Within block, pens were randomly assigned to one of four bunk allotment treatments: 25.4, 38.1, 50.8, or 63.5 cm of bunk per head for a 58-d receiving period. Calves were fed at 0700 h once daily at 1.8% of bodyweight (dry matter basis) from February 2 to March 13, 2021; thereafter the daily feed allotment was increased to 2.0% of bodyweight. The diet contained (dry matter basis) 39.5% dry-rolled corn, 7.5% supplement, 40% wet corn gluten feed, and 13% prairie hay. Steers were individually weighed on days 29 and 58 and pen weights were measured weekly to determine feed offered for the following week. Body weights on days 29 and 58, dry matter intake, or gain-to-feed ratio during the receiving period did not differ (P ≥ 0.34) between treatments. During the first 29 d, average daily gain (ADG) increased linearly as bunk space increased (P = 0.03); however, no treatment effects were observed thereafter. In addition, ADG standard deviation from days 0 to 29 responded quadratically (P = 0.05) where ADG standard deviation tended to be greater in the 38.1-cm allotment and was greater in the 50.8-cm allotment compared to the 25.4-cm allotment (P = 0.07 and P = 0.04, respectively). Bunk score tended to decrease linearly as bunk allotment decreased (P = 0.06). Following the receiving period, steers were blocked by bunk treatment and randomly assigned to 1 of 18 pastures. Steers were grazed for 90-d from May to August at a targeted stocking density of 280 kg live-weight ˖ ha–1. During the grazing season, ADG increased linearly with reduced (P < 0.01) bunk allotment; however, body weights did not differ (P = 0.91) between bunk treatments at the completion of the grazing period. In addition, overall total body weight gains and ADG from the receiving and grazing periods did not differ (P > 0.57) between bunk treatments. We interpreted our data to suggest that bunk space allotments of 25.4 to 63.5 cm per head had minimal impact on growth performance during a 58-d receiving period and did not affect final body weights following a 90-d grazing season.
      PubDate: Wed, 27 Jul 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac096
      Issue No: Vol. 6, No. 3 (2022)
       
  • Comparison of two distinct arrival and treatment programs for bovine
           respiratory disease in high-risk feeder cattle entering a feedlot

    • Abstract: AbstractAntimicrobial metaphylaxis of high-risk cattle entering the feedlot is a common management strategy implemented against bovine respiratory disease (BRD). Typically, following a prescribed postmetaphylactic interval (PMI), animals displaying clinical signs of BRD are pulled from the feedlot pen and treated with antimicrobials when treatment criteria are met. The objective of this study was to compare 2 distinct sequential BRD treatment protocols each consisting of a metaphylactic antimicrobial plus 2 potential subsequent as-needed treatment antimicrobials. Heifers at high-risk for BRD (n = 1000; initial BW = 229 kg ± 1.6) purchased from sale barns in the southeastern U.S. were transported to a contract research feedlot in Nebraska and randomly assigned to 1 of 2 experimental groups (10 blocks of 100 animals each; 50 per treatment group). Experimental groups consisted of: (1) tulathromycin metaphylaxis (2.5 mg/kg) followed by ceftiofur crystalline free acid (6.6 mg/kg) and danofloxacin (8 mg/kg) for subsequent first and second as-needed BRD treatment, respectively (TCD) or (2) tildipirosin metaphylaxis (4 mg/kg) followed by florfenicol-flunixin meglumine (40 mg/kg florfenicol; 2.2 mg/kg flunixin meglumine) and enrofloxacin (12.5 mg/kg) for subsequent first and second as-needed BRD treatment, respectively (TFFE). Following expiration of the 7-d PMI, calves that showed signs of clinical BRD were pulled and examined to determine if treatment was necessary based on a clinical attitude score (CAS). Heifers with a CAS of 1 accompanied by ≥40°C rectal temperature, and all heifers with a CAS ≥ 2 regardless of rectal temperature, received the appropriate first-treatment antimicrobial. Upon relapse, following expiration of the post-treatment interval (PTI), heifers received the appropriate second-treatment antimicrobial. In the first 90 d, calves in the TFFE experimental group received more first-treatments than calves in the TCD experimental group (P = 0.054) and resulted in 50% greater mortality (P < 0.043) relative to the TCD heifers. From d 0 to closeout, first-treatment morbidity as well as mortality were greater in TFFE relative to TCD (P ≤ 0.032). Growth performance did not differ between treatments in the first 90 d; however, ADG was greater (P = 0.033) and G:F improved (P = 0.014) at closeout in TCD versus TFFE on a deads-in basis. Closeout economics revealed a $50.78/animal greater profit in the TCD experimental group relative to TFFE.
      PubDate: Wed, 27 Jul 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac102
      Issue No: Vol. 6, No. 3 (2022)
       
  • Impact of concentrations of camphor on the in vitro mixed ruminal
           microorganism fermentation from goats selected for consumption of low and
           high levels of Juniperus spp.-2

    • Abstract: AbstractThe microbial population in the gastrointestinal tract of ruminant animals aids in the utilization of forages with high levels of secondary plant compounds. Two divergent bloodlines of meat goats have been selected by screening fecal samples with near-infrared reflectance spectroscopy to assess the goat’s consumption of high or low levels of Juniperus sp. leaves containing several monoterpenes, including camphor. The mechanism by which these goats can consume greater concentrations of Juniperus spp. leaves than their counterparts is unclear, and therefore, this study was designed to determine if differences existed between the ruminal microbial populations of the low and high juniper-consuming bloodlines (LJC vs. HJC) by analyzing their ruminal microbiota and fermentation end products. In the present study, concentrations (0.00, 0.5, 0.99, 1.97, or 5.91 mM) of camphor were added to mixed ruminal microorganism fermentation. Five LJC and five HJC goats were fed a juniper-free diet (n = 10), and five LJC and five HJC goats (n = 10) were fed a diet that contained 30% fresh Juniperus ashei leaves for 21 d prior to ruminal fluid collection. In vitro fermentations used LJC and HJC, ruminal fluid inoculum added (33% v/v) to anoxic media in sealed Balch tubes. Camphor increased (P < 0.05) total short-chain fatty acid (SCFA) concentrations for all but one experimental group. Between the main dietary and bloodline goat effects, the diet was significant for all SCFA results except butyrate. In contrast, bloodline was only significant for acetate and butyrate molar proportions. Rumen fluid from juniper-free-fed goats exhibited greater concentrations of Ruminococcaceae, whereas juniper-fed goats contained more Coriobacteriaceae. Results demonstrated that mixed ruminal microorganisms fermentations from HJC goats did not produce greater concentrations of SCFAs or have the ability to degrade camphor at a higher rate than did that from LJC goats. Results suggest that camphor tolerance from J. ashei, was related to hepatic catabolic mechanisms instead of ruminal microbial degradation; however, further in vivo work is warranted.
      PubDate: Wed, 27 Jul 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac098
      Issue No: Vol. 6, No. 3 (2022)
       
  • Impact of camphor on the in vitro mixed ruminal microorganism fermentation
           from goats selected for consumption of low and high levels of Juniperus
           spp. 1

    • Abstract: AbstractEncroaching plant species in West Texas continues to significantly reduce livestock production capacity and cause an imbalance between plant and livestock ecology. Juniperus ashei and Juniperus pinchotii are encroaching species rarely used by browsing animals, mainly due to phytochemical defenses. Juniperus spp. contain large concentrations of monoterpenes in their essential oil profiles to deter herbivory. Since 2003, two divergent bloodlines of meat goats have been selected to consume low or high (LJC or HJC) amounts of juniper foliage, through screening fecal samples with near-infrared reflectance spectroscopy. However, it remains unclear whether HJC goats expressed a physiological ability to consume a greater amount of juniper or if they were colonized by a ruminal microbial population that could detoxify juniper phytochemicals. Therefore, this study aimed to investigate the impact of 0.00 and 1.97 mM of camphor on the mixed ruminal microorganism fermentation after 0, 1, 2, 4, 12, and 24 h of incubation. Five LJC and five HJC goats were fed a juniper-free diet (n = 10) and five LJC and five HJC goats (n = 10), were fed a diet containing 30% fresh J. ashei leaves for 21 days prior to ruminal fluid collection. In vitro fermentations used LJC and HJC, ruminal fluid inoculum was added (33% v/v) to anoxic media in sealed Balch tubes. Total short-chain fatty acid (SCFA) production and acetate to propionate ratio were increased (P < 0.05), but there was no effect on pH (6.56 ± 0.09). Goats that received the juniper-free diet had higher (P < 0.05) SCFA production than juniper-containing diets. There was no consistent difference in LJC and HJC microbial fermentation end products caused by the addition of 1.97 mM of camphor, and goats receiving a juniper-free diet consistently generated more SCFAs in the presence of 1.97 mM of camphor. Furthermore, bloodline differences in juniper consumption were likely related to physiological adaption capacities within the animal and not a ruminal microbial detoxification advantage.
      PubDate: Wed, 27 Jul 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac097
      Issue No: Vol. 6, No. 3 (2022)
       
  • Canola as a potential forage

    • Abstract: AbstractThe nutritive quality of four cultivars of canola forage (Brassica napus L.), Orient, Midas, Global, and Hybrid (Cobra × Regent), which were harvested in the early-spring period, were compared with green-winter barley (GWB) in terms of their yields, chemical composition, in vitro gas production variables, in situ crude protein (CP) degradation, and predicted dry matter intake (PDMI). Data were statistically analyzed using a completely randomized design with four replications and three samples per replication. The study was based on a randomized complete block design, and data were analyzed using SAS, general linear model procedure for normal distribution. The canola dry matter (DM) yield was highest in Orient cultivar and lowest in Midas (P < 0.05). Organic matter (OM), CP, neutral detergent fiber (NDF), and lignin(sa) concentration of the four cultivars ranged from 862 to 865, 218 to 247, 295 to 340, and 35 to 53 g/kg DM, respectively. The estimated OM disappearance (OMD), effective degradability of CP, effective rumen degradable protein (ERDP), digestible undegradable protein, and metabolizable protein (MP) of the forages were from 636 to 671 g/kg, 878 to 910, 172 to 193, 1.9 to 3.4, and 112 to 126 g/kg DM, respectively. Compared to Global and Hybrid cultivars, Orient and Midas contained higher CP, OMD, ERDP, MP concentration, and PDMI, but lower NDF, acid detergent fiber (ADF), and lignin(sa) concentrations (P < 0.05). The level of glucosinolates in the forages ranged from 0.38 to 1.51 µmol/g DM, which is below the detrimental level for ruminants. Compared to winter canola cultivars, GWB had higher DM yield (P < 0.003), NDF, lignin(sa), PDMI (P < 0.01), and digestible undegradable protein (P < 0.04), but had lower OMD (P < 0.03), ERDP (P = 0.01), and MP (P < 0.009). Based on the obtained results, the variation in the nutritive quality among the canola cultivars is relatively small, and the Orient cultivar, which is most comparable to GWB, was judged to be nutritionally the best among the cultivars.
      PubDate: Sat, 23 Jul 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac100
      Issue No: Vol. 6, No. 3 (2022)
       
  • Validation of maternal and terminal sheep breeding objectives using Irish
           field data

    • Abstract: AbstractGenetic evaluations provide producers with a tool to aid in breeding decisions and highlight the increase in performance achievable at the farm level through genetic gain. Despite this, large-scale validation of sheep breeding objectives using field data is lacking in the scientific literature. The objective of the present study was to evaluate the phenotypic differences for a range of economically important traits for animals divergent in genetic merit for the Irish national maternal and terminal sheep breeding objectives. A dataset of 17,356 crossbred ewes and 54,322 progeny differing in their maternal and terminal breeding index recorded in 139 commercial flocks was available. The association of the maternal index of the ewe or terminal index of the ram and a range of phenotypic performance traits, including lambing, lamb performance, ewe performance, and health traits, were undertaken. Ewes excelling on the maternal index had higher litter sizes and produced progeny with greater perinatal lamb survival, heavier live weights from birth to postweaning and reduced days to slaughter (P < 0.05). Ewe maternal index had no quantifiable impact on lambing ease, carcass conformation, or fat, the health status of the ewe or lamb, ewe barren rate, or ewe live weight. Lambs born to rams of superior terminal index produced heavier lambs from preweaning onwards, with a reduced day to slaughter (P < 0.05). Lambing traits, lamb health, and carcass characteristics of the progeny did not differ between sires stratified as low or high on the terminal index (P > 0.05). Results from this study highlight that selecting either ewes or rams of superior maternal or terminal attributes will result in an improvement on pertinent performance traits of the national sheep flock, resulting in greater flock productivity and profitability.
      PubDate: Sat, 23 Jul 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac099
      Issue No: Vol. 6, No. 3 (2022)
       
  • Energy restriction and housing of pregnant beef heifers in mud decreases
           body weight and conceptus free live weight

    • Abstract: AbstractAverage temperatures in the Midwest, USA are predicted to increase 2–9°C by the end of the century; resulting in muddy pastures for spring calving beef heifers as they enter late gestation. The objective of this study was to evaluate the effects of muddy conditions on heifer body weight (BW), body condition score (BCS), conceptus free live weight (CFLW), and fetal growth when heifers were energy restricted during late gestation. Eighteen Angus heifers (n = 9/treatment) were paired based on initial BW. One heifer from each BW pair was randomly allocated to either the mud (MUD) or control (CON) treatment on day 196 of gestation. Pens in the CON treatment were bedded with wood chips, while pens in the MUD treatment were filled with mud (average depth of 19.5 ± 7.9 cm). Heifers were housed individually and fed the same diet that consisted of a limit-fed total mixed ration from day 196 to 266 of gestation that was formulated to meet 66% of the net energy for maintenance, growth, and gestation requirements. Requirements and the amount of the diet offered were adjusted weekly, and heifers were weighed and sampled for blood metabolites weekly. Data were analyzed as a randomized complete block design with repeated measurements. There was a treatment × day of gestation interaction, such that heifers had similar BW, BCS, and CFLW on day 196 of gestation. By day 266 of gestation; however, heifers in the MUD treatment weighed 43.5 kg less (P < 0.01) and were 1.8 BCS units less (P < 0.01) than heifers in the CON treatment. This is further supported by the treatment × day effects we observed for back fat (BF) and rump fat (RF) thickness, such that the MUD heifers had less BF (P = 0.02) and RF (P < 0.01) by day 266 of gestation. There was a marginally significant difference for gestation length (P = 0.06), such that heifers in the MUD treatment calved approximately 3.1 days before the heifers in the CON treatment. Though heifers in the MUD treatment decreased their BW and CFLW during the treatment period, we did not observe a difference in calf birth weight (P = 0.34), calf plasma IgG concentration (P = 0.37), or calf weaning weight (P = 0.63). Despite heifers in the MUD treatment having greater BW, CFLW, and BCS losses compared with the heifers in the CON treatment, the heifers in the MUD treatment seemed to prioritize fetal growth, as they mobilized their body tissues to meet the energetic demands of pregnancy.
      PubDate: Fri, 22 Jul 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac101
      Issue No: Vol. 6, No. 3 (2022)
       
  • Effects of calcium-magnesium carbonate and calcium-magnesium hydroxide as
           supplemental sources of magnesium on ruminal microbiome

    • Abstract: AbstractOur objective was to evaluate the inclusion of calcium-magnesium carbonate [CaMg(CO3)2] and calcium-magnesium hydroxide [CaMg(OH)4] in corn silage-based diets and their impact on ruminal microbiome. Our previous work showed a lower pH and molar proportion of butyrate from diets supplemented with [CaMg(CO3)2] compared to [CaMg(OH)4]; therefore, we hypothesized that ruminal microbiome would be affected by Mg source. Four continuous culture fermenters were arranged in a 4 × 4 Latin square with the following treatments defined by the supplemental source of Mg: 1) Control (100% MgO, plus sodium sesquicarbonate as a buffer); 2) CO3 [100% CaMg(CO3)2]; 3) OH [100% CaMg(OH)4]; and 4) CO3/OH [50% Mg from CaMg(CO3)2, 50% Mg from CaMg(OH)4]. Diet nutrient concentration was held constant across treatments (16% CP, 30% NDF, 1.66 MCal NEl/kg, 0.67% Ca, and 0.25% Mg). We conducted four fermentation periods of 10 d, with the last 3 d for collection of samples of solid and liquid digesta effluents for DNA extraction. Overall, 16 solid and 16 liquid samples were analyzed by amplification of the V4 variable region of bacterial 16S rRNA. Data were analyzed with R and SAS to determine treatment effects on taxa relative abundance of liquid and solid fractions. Correlation of butyrate molar proportion with taxa relative abundance was also analyzed. Treatments did not affect alpha and beta diversities or relative abundance of phylum, class and order in either liquid or solid fractions. At the family level, relative abundance of Lachnospiraceae in solid fraction was lower for CO3 and CO3/OH compared to OH and Control (P < 0.01). For genera, abundance of Butyrivibrio (P = 0.01) and Lachnospiraceae ND3007 (P < 0.01) (both from Lachnospiraceae family) was lower and unclassified Ruminococcaceae (P = 0.03) was greater in CO3 than Control and OH in solid fraction; while abundance of Pseudobutyrivibrio (P = 0.10) and Lachnospiraceae FD2005 (P = 0.09) (both from Lachnospiraceae family) and Ruminobacter (P = 0.09) tended to decrease in CO3 compared to Control in liquid fraction. Butyrate molar proportion was negatively correlated to Ruminococcaceae (r = –0.55) in solid fraction and positively correlated to Pseudobutyrivibrio (r = 0.61) and Lachnospiraceae FD2005 (r = 0.61) in liquid. Our results indicate that source of Mg has an impact on bacterial taxa associated with ruminal butyrate synthesis, which is important for epithelial health and fatty acid synthesis.
      PubDate: Thu, 07 Jul 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac092
      Issue No: Vol. 6, No. 3 (2022)
       
  • Evaluation of the association between plasma glucose-dependent
           insulinotropic polypeptide, respiratory quotient, and intramuscular fat
           deposition in feedlot cattle fed different levels of dry matter intake

    • Abstract: AbstractThe objectives of this trial were to evaluate the association between different levels of dry matter intake (DMI) on gas exchange, plasma glucose-dependent insulinotropic polypeptide (GIP) concentration, and intramuscular (IM) fat deposition. We used 60 individually fed backgrounded Angus × SimAngus-crossbred steers (n = 30) in a randomized complete block design. Steers (paired by body weight [BW] and gain to feed ratio [G:F]) were randomly allocated to one of the following treatments: ad libitum intake (AI) or restricted intake (RI; the same diet fed at 85% of the AI) of a finishing diet. The diet contained 61% cracked corn, 9% corn silage, 15% distillers’ dried grains with solubles, 5% soyhulls, and 10% of a protein-mineral-vitamin premix. Measurements of CO2 emission and consumption of O2, and respiratory quotient (RQ) were taken using the GreenFeed system (n = 15/treatment). Plasma and gas samples were collected 10 d before slaughter, 1 h before and 2 h after feeding. Plasma glucose, non-esterified fatty acids, GIP, and insulin concentration and gasses (O2, CO2, and RQ) were analyzed using the MIXED procedure of SAS evaluating the fixed effect of treatment, time (repeated measurement) and their interaction, and the random effect of the block. Final BW and carcass characteristics were analyzed with a similar model, without the time statement and its interaction. Compared with RI, AI steers had greater (P < 0.01) DMI and average daily gain (ADG). Steers on AI had greater final BW (P = 0.02), tended to have a greater ribeye area (P = 0.09), and had lower plasma GIP concentration (P = 0.04). There was no treatment effect (P ≥ 0.11) on G:F, subcutaneous backfat (BF), and IM fat, O2 consumption, CO2 emission, and RQ. Plasma glucose concentration of AI steers was greater before and after feeding than RI (P < 0.05). In conclusion, feeding steers ad libitum increased DMI, ADG, and plasma glucose and GIP concentration but does not affect G:F, BF, IM fat, CO2 emission, and O2 consumption. Plasma GIP concentration and RQ are not associated with IM fat deposition.
      PubDate: Fri, 01 Jul 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac089
      Issue No: Vol. 6, No. 3 (2022)
       
  • Assessing a pilot co-operative-based workshop-subsidy model toward
           improving small-scale chicken production in peri-urban Nepal

    • Abstract: AbstractFarmers in Nepal face many of the same global challenges associated with initiating and scaling poultry husbandry as many other developing countries. These include access to innovative approaches in finance, credit, coop design, marketing, and sales. As with most low-income countries, Nepalese poultry farmers also lack adequate training in poultry husbandry including biosecurity. In this paper, we describe a collaborative workshop-subsidy approach to addressing these challenges conducted by a partnership with the UC Davis School of Veterinary Medicine, the College of Engineering, the School of Education, and a farming co-operative based in the semi-rural area of Bhaktapur, Nepal. The program included two workshops covering aspects of poultry rearing including coop construction, chick rearing, biosecurity, and husbandry. Both workshops were a combination of lectures and hands-on learning. Following completion of the workshops, each farmer received subsidized materials for coop construction and poultry rearing. The co-operative provided training facilities and a market for selling eggs. Despite an outbreak of Highly Pathogenic Avian Influenza (HPAI), which affected the scale of program implementation, our results suggest that the workshop subsidy collaborative approach can be successful in reducing market entry barriers. Our 6-mo post-workshop survey showed that two-thirds of the workshop participants ultimately built their own coop and raised chicks. Half of these participants reported market available egg production and a doubling of egg consumption at home.
      PubDate: Thu, 30 Jun 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac071
      Issue No: Vol. 6, No. 3 (2022)
       
  • Impacts of including Sweet Bran and wet distillers grains with solubles
           alone or in combination in finishing cattle diets on physically effective
           fiber concentrations and rumen buffering characteristics of feedlot cattle
           

    • Abstract: AbstractThis study evaluated the effects of Sweet Bran (SB) and wet distillers grains with solubles (WDGS) in the diet alone or in combination on physically effective neutral detergent fiber (peNDF), ruminal pH, and rumination behavior of finishing beef cattle. For this study, 455 steers (373 ± 15.5 kg) were allocated to 48 pens in a randomized complete block design. Treatments (n = 12 pens per treatment) were one of four steam-flaked corn-based diets containing no corn-milling products (CON), 20% WDGS (WDGS20), 20% SB (SB20), or 20% SB and 10% WDGS (COMBO). Within each pen, two steers were randomly selected to receive an indwelling ruminal pH bolus to quantify ruminal pH and a 3-axis accelerometer tag to measure rumination for the first 92 d of the study. Diet samples were collected weekly to determine particle size, neutral detergent fiber (NDF) concentration, and peNDF. Physically effective NDF was calculated using both the proportion of particles > 4.0 mm (peNDF4.0) and the proportion of particles > 8.0 mm (peNDF8.0). The percentage of particles > 4.0 mm was greatest (P < 0.01) for CON, intermediate for SB20, and least for WDGS20 and COMBO. Both NDF (P < 0.01) and peNDF4.0 (P < 0.01) were greatest for COMBO, intermediate for WDGS20 and SB20, and least for CON. The percentage of particles > 8.0 was greatest (P < 0.01) for CON, intermediate for WDGS20 and SB20, and least for COMBO, but peNDF8.0 did not differ (P = 0.40). A diet × day interaction (P < 0.01) was observed for daily rumination minutes per kg of DMI, NDF, peNDF4.0, and peNDF8.0. A diet × hour interaction (P < 0.01) was observed where CON cattle spent less time ruminating at 0800 and 1000 h in a 24 h period. Daily ruminal pH was greatest (P < 0.01) for COMBO, intermediate for SB20 and WDGS20, and least for CON. A diet × hour interaction (P < 0.01) was also observed for circadian ruminal pH, where pH was least for CON from 0800 to 1800 h. Relationships between peNDF, rumination behavior, and ruminal pH observed in this study suggest that SB and WDGS similarly enhance rumen buffering capacity when steam-flaked corn is replaced in the diet.
      PubDate: Wed, 29 Jun 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac091
      Issue No: Vol. 6, No. 3 (2022)
       
  • Production cow-calf responses from perennial forage-based and integrated
           beef-cropping systems

    • Abstract: AbstractAn experiment was conducted to measure production responses of an alternative cow-calf production system integrated into a cropping system without access to perennial forage compared to a traditional cow-calf system utilizing perennial forage. Multiparous, cross-bred beef cows (n = 160; average age = 6.2 ± 2.8 yr) were utilized in a randomized complete block experimental design and unstructured treatment design. Upon initiation, cows were blocked by age and stratified by source, assigned randomly to one of two production systems, each with four replicates (n = 20 cows/replicate). Once allotted to their treatment groups, cows remained in their experimental units for the duration of the experiment. Treatments were: 1) a traditional system consisting of April to May calving with smooth bromegrass pasture and grazed corn residue as forage resources (TRAD); 2) an alternative system consisting of July to August calving utilizing partial-drylot feeding, summer-planted oats, and corn residue grazing (ALT). There were no differences (P ≥ 0.27) in calving rates (91.8 vs. 86.7 ± 2.92%), pregnancy rates (89.3 vs. 89.9 ± 2.66%), and weaning rates (87.2 vs. 82.3 ± 3.29%) for TRAD vs. ALT, respectively. However, there was an increase (P = 0.04) in the rate of twin offspring in ALT (2.9 vs. 9.4 ± 2.36% for TRAD vs. ALT, respectively). One calf from the set of twins was selected randomly at birth to be removed from the experiment, so the production data are only from single calves. There was no difference (P = 0.47) in calf body weight at birth (40 vs. 39 ± 0.7 kg for TRAD vs. ALT, respectively). At weaning, calves in the ALT system were lighter (P < 0.01) at the same day of age (184 vs. 229 ± 5.5 kg) compared to TRAD calves. Cows from the ALT system had fewer (P < 0.01) kg weaned per cow exposed to bull (150 vs. 199 ± 7.2 kg) compared to TRAD cows. Apart from the twinning rate, no differences in reproductive performance were observed among systems. However, reduced weaning weights and kilogram of weaned calf per cow exposed may negatively impact revenue to the cow-calf enterprise of the ALT system.
      PubDate: Wed, 29 Jun 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac090
      Issue No: Vol. 6, No. 3 (2022)
       
  • Standardized ileal digestible amino acids and digestible energy contents
           in two modified soy protein concentrates and soybean meal fed to growing
           pigs1

    • Abstract: AbstractSix ileal-cannulated barrows (28.0 ± 1.3 kg initial BW) were used in a replicated 3 × 3 Latin square design with one additional period (n = 7 or 6) to determine standardized ileal digestible (SID) AA and digestible energy of two modified soy protein concentrates [MSPC1 and MSPC2] and soybean meal (SBM). Pigs were fed one of three cornstarch-based diets with either MSPC1 or MSPC2 or SBM as the sole source of AA at a rate of 2.8 times the estimated maintenance energy requirement. In each period, pigs were adapted to diets for 7 d followed by 2 d of fecal collection and subsequently, 2 d of continuous ileal digesta collection for 8 h. The SID of AA was calculated using basal endogenous losses from a previous study for pigs fed a nitrogen-free diet. The digestible energy of the ingredients was calculated according to the difference method using a nitrogen-free diet that contained the same cornstarch:sucrose:oil ratio as the three test diets. The total Lys content was 33% and 38% greater for MSPC1 vs. MSPC2 and SBM, respectively. The SID of crude protein was greater for MSPC1 (96.9%) than for SBM (91.3%; P < 0.05), whereas an intermediate value was observed for MSPC2 (94.3% ± 1.2%). The SID of Ile (93.8%), Leu (93.6%), Lys (93.9%), Phe (96.7%), and Val (93.2%) were not different between MSPC1 and MSPC2 but greater than for SBM (88.8% ± 1.3%, 87.8% ± 1.2%, 84.5% ± 1.7%, 92.9% ± 1.0%, 86.5% ± 1.7% for Ile, Leu, Lys, Phe, and Val, respectively; P < 0.05). The SID of His and Thr was greater for MSPC1 than MSPC2 and SBM (P < 0.05), which were not different. The SID of Met was greater for MSPC1 and SBM vs. MSPC2 (P < 0.05). The SID of Arg was greater for MSPC1 than MSPC2 and SBM (P < 0.05), and greater for MSPC2 than SBM (P < 0.05). The digestible energy was greater for MSPC1 (4,677 kcal/kg) than MSPC2 and SBM (average; 3,896 ± 239 kcal/kg; P < 0.05), which were not different. Therefore, the MSPC1 was a better source of SID Lys and digestible energy than either MSPC2 or SBM and could be used as a highly digestible protein ingredient in swine rations.
      PubDate: Sun, 26 Jun 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac088
      Issue No: Vol. 6, No. 3 (2022)
       
  • In which department should forages be taught'

    • Abstract: AbstractForages as a discipline and forage workers in general are declining nationwide. Why is this' Could it be the department in which forage courses are taught' This paper will take a brief look at the history of forage/livestock grazing research, who currently teaches a forage course and where forages are currently taught at various land grant institutions. Finally, the question and a potential answer is provided regarding where might the forage discipline be taught to increase their exposure to undergraduate students.
      PubDate: Sat, 25 Jun 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac087
      Issue No: Vol. 6, No. 3 (2022)
       
  • Immunomodulatory potential of black soldier fly larvae: applications
           beyond nutrition in animal feeding programs

    • Abstract: AbstractInsect-derived ingredients, including whole larvae, protein-rich meal, and oil, have been extensively studied in recent years and shown to be a sustainable source of quality nutrition for virtually all animal species and life stages. In addition to the ability to use these ingredients as a source of essential nutrition, more recent research has demonstrated the potential for the immunomodulatory activity of various components of insect-derived ingredients. For all insects studied, antimicrobial peptides make up a critical part of the insects’ innate immune system and these peptides have antimicrobial efficacy when purified from hemolymph and tested in vitro. From black soldier fly larvae, in particular, lauric acid is a predominant fatty acid deposited into the insect, and lauric acid also has potential antimicrobial activity in vitro and in vivo. Finally, the chitin and chitosan components of the insect exoskeleton may modulate microbial activity in a variety of ways. In companion animals, poultry, and livestock species, insect-derived ingredients have shown the potential to reduce the impact of actual or simulated disease challenge on several parameters of animal health and well-being. This review describes the current state of knowledge of the immunomodulatory potential of insect-derived ingredients.
      PubDate: Wed, 22 Jun 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac084
      Issue No: Vol. 6, No. 3 (2022)
       
  • Meta-analysis of the effects of monensin on performance of beef
           replacement heifers and beef cows

    • Abstract: AbstractAlthough performance benefits of monensin have been extensively studied in finishing cattle, growing cattle, and dairy cows, considerably less published work is available evaluating response to monensin supplementation in cow-calf production systems. This meta-analysis investigated the impacts of monensin on performance of beef cows and developing replacement heifers. The replacement heifer analysis was conducted using data from 18 different peer-reviewed publications and experiment station reports. The mature cow analysis included 21 different publications and experiment station reports. The metaphor package (version 2.4-0; Viechtbauer, 2010) for R (version 4.0.3; www.r-project.org) was used to determine the overall effect size of monensin compared to a negative control. Each study’s n, means, and SEM or P value was used to calculate the mean difference and estimate of within study variance for responses of interest. In replacement heifers, monensin treatment increased (P < 0.01); average daily gain (+0.03 ± 0.008 kg/d), feed efficiency (+0.013 ± 0.008 gain:feed), and percentage cycling before the breeding season (+15.9 ± 5.13%); while decreasing (P < 0.01): dry matter intake (0.293 ± 0.081 kg), and age at puberty (‐8.9 ± 1.48 d). Six studies reporting ad libitum forage intake for mature cows showed decreased (P = 0.008) DMI by 0.85 ± 0.32 kg/d. Six studies reported milk yield and revealed an increase (P = 0.01) of 0.39 ± 0.15 kg/d when cows were supplemented with monensin. Monensin supplementation resulted in a reduction (P = 0.02) in days to first estrus by 18 ± 8.2 d and percentage of cows exhibiting estrus prior to the breeding season was increased by 19 ± 8% (P = 0.03). There were no differences in artificial insemination pregnancy nor total pregnancy for either the heifer or mature cow data sets. This analysis indicates potential for use of monensin in heifer development and beef cow production systems. Further research is needed to elucidate the effects on reproductive efficiency, DMI, milk production, weight, and body composition change.
      PubDate: Wed, 22 Jun 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac086
      Issue No: Vol. 6, No. 3 (2022)
       
  • Impacts of a post-transport/pre-processing rest period on the growth
           performance, anthelmintic efficacy, and serum metabolite changes in cattle
           entering a feed yard

    • Abstract: AbstractA total of 80 crossbred, high-risk heifers (initially 250 ± 4.2 kg BW), were transported from an Oklahoma City, Oklahoma sale barn to the Kansas State University Beef Cattle Research Center. Cattle were unloaded and randomly placed into one of four receiving pens and provided ad libitum hay and water. Each pen was randomly assigned to one of the four rest times before processing: (1) immediately upon arrival (0); (2) after a 6-h rest period (6); (3) after a 24-h rest period (24); and (4) after a 48-h rest period (48). After all cattle were processed, heifers were allotted into individual pens with ad libitum access to a receiving ration and water. Heifers were weighed individually on d 0, 7, 14, 21, 28, and 35 to calculate average daily gain (ADG). Feed added and refusals were measured daily to determine dry matter intake (DMI). A fecal egg count reduction test and analysis of blood serum metabolites were also conducted. All data were analyzed using the GLIMMIX procedure of SAS (v. 9.4, Cary, NC) with individual animal as the experimental unit. Processing time did not impact (P > 0.05) heifer BW or ADG. From d 0 to 35, DMI decreased linearly (P = 0.027) as rest time increased. The number of days for heifers to reach a DMI of 2.5% BW was linearly increased (P = 0.023) as rest time increased. There was no evidence of differences (P ≥ 0.703) among rest times for feed efficiency. While morbidity did not differ between treatments (P > 0.10), mortality increased linearly (P = 0.026) as the time of rest increased. A significant processing time × day interaction (P < 0.0001) was observed for the prevalence of fecal parasites, where the percentage of positive samples was significantly lower 14-d after anthelmintic treatment, regardless of the processing time. Serum IBR titer for heifers processed at either 0 or 6-h upon arrival was significantly higher (P < 0.01) on d 35 compared to d 0. Heifers processed after a 48-h rest period had significantly higher glucose values (P < 0.01) on d 0 compared to heifers processed at 0, 6, or 24-h. In summary, rest time prior to processing did not impact receiving calf growth performance. A 6-h rest period upon arrival appeared to be most beneficial to DMI. Anthelmintic treatment at processing reduced the parasitic load in heifers processed at all times. Vaccine titer did not increase after initial processing in heifers processed 24- or 48-h after arrival, indicating the seroconversion of IBR antibodies during the longer rest period.
      PubDate: Tue, 21 Jun 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac085
      Issue No: Vol. 6, No. 3 (2022)
       
  • Effects of a multi-strain Bacillus subtilis-based direct-fed microbial on
           immunity markers and intestinal morphology in diets fed to weanling pigs

    • Abstract: AbstractThe objective of this experiment was to evaluate the effects of a multi-strain Bacillus subtilis-based direct-fed microbial (DFM) on nursery pig health as indicated by intestinal mucosal and blood plasma immunological markers and intestinal morphology. Eighty pigs, of equal number of barrows and gilts (initial BW: 7.0 ± 0.60 kg), weaned at 21 ± 1 d of age were randomly allotted to sixteen pens, with five pigs per pen. Two dietary treatments were implemented, a basal control (CON) and a basal control plus DFM (CDFM). Both diets were corn, soybean meal, and distillers dried grains based and were formulated to meet or exceed all nutritional requirements (NRC, 2012) and manufactured on site. Diets were fed for 42 d. On d 21 and 42 of the experiment, one pig per pen was randomly selected and euthanized, with equal number of males and females represented. Blood samples were collected prior to euthanasia for assessment of plasma concentrations of immunoglobulin A (IgA) and intestinal fatty acid binding protein. Segments of the gastrointestinal tract including duodenum, jejunum, ileum, ascending and distal colon were removed for analysis of intestinal morphology, and levels of interleukin 6, interleukin 10 (IL-10), and tumor necrosis factor alpha. Jejunal villus height was greater in the CDFM pigs as compared with CON pigs (P = 0.02) and ascending colon crypt depth tended to be greater on d 21 (P = 0.10). Compared to CON, CDFM significantly increased overall plasma IgA (P = 0.03) (0.58 vs. 0.73 0.05 mg/mL, respectively), while it tended to increase plasma IgA (P = 0.06) on d 21 (0.34 vs. 0.54 ± 0.07 mg/mL, respectively) and tended to increase overall IL-10 (P = 0.10) in the jejunum (113 vs. 195 ± 35 pg/mL, respectively). Addition of a multi-strain Bacillus subtilis-based DFM may have an early benefit to nursery pig health status, observed through specific changes in morphology and both systemic and localized immunological markers.
      PubDate: Mon, 20 Jun 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac083
      Issue No: Vol. 6, No. 3 (2022)
       
  • Evaluation of a novel computer vision-based livestock monitoring system to
           identify and track specific behaviors of individual nursery pigs within a
           group-housed environment

    • Abstract: AbstractAnimal behavior is indicative of health status and changes in behavior can indicate health issues (i.e., illness, stress, or injury). Currently, human observation (HO) is the only method for detecting behavior changes that may indicate problems in group-housed pigs. While HO is effective, limitations exist. Limitations include HO being time consuming, HO obfuscates natural behaviors, and it is not possible to maintain continuous HO. To address these limitations, a computer vision platform (NUtrack) was developed to identify (ID) and continuously monitor specific behaviors of group-housed pigs on an individual basis. The objectives of this study were to evaluate the capabilities of the NUtrack system and evaluate changes in behavior patterns over time of group-housed nursery pigs. The NUtrack system was installed above four nursery pens to monitor the behavior of 28 newly weaned pigs during a 42-d nursery period. Pigs were stratified by sex, litter, and randomly assigned to one of two pens (14 pigs/pen) for the first 22 d. On day 23, pigs were split into four pens (7 pigs/pen). To evaluate the NUtrack system’s capabilities, 800 video frames containing 11,200 individual observations were randomly selected across the nursery period. Each frame was visually evaluated to verify the NUtrack system’s accuracy for ID and classification of behavior. The NUtrack system achieved an overall accuracy for ID of 95.6%. This accuracy for ID was 93.5% during the first 22 d and increased (P < 0.001) to 98.2% for the final 20 d. Of the ID errors, 72.2% were due to mislabeled ID and 27.8% were due to loss of ID. The NUtrack system classified lying, standing, walking, at the feeder (ATF), and at the waterer (ATW) behaviors accurately at a rate of 98.7%, 89.7%, 88.5%, 95.6%, and 79.9%, respectively. Behavior data indicated that the time budget for lying, standing, and walking in nursery pigs was 77.7% ± 1.6%, 8.5% ± 1.1%, and 2.9% ± 0.4%, respectively. In addition, behavior data indicated that nursery pigs spent 9.9% ± 1.7% and 1.0% ± 0.3% time ATF and ATW, respectively. Results suggest that the NUtrack system can detect, identify, maintain ID, and classify specific behavior of group-housed nursery pigs for the duration of the 42-d nursery period. Overall, results suggest that, with continued research, the NUtrack system may provide a viable real-time precision livestock tool with the ability to assist producers in monitoring behaviors and potential changes in the behavior of group-housed pigs.
      PubDate: Thu, 16 Jun 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac082
      Issue No: Vol. 6, No. 3 (2022)
       
  • Oral supplementation of alkaline phosphatase in poultry and swine

    • Abstract: AbstractThe importance of intestinal alkaline phosphatase (IAP) in maintaining gut health and intestinal homeostasis is well established. The objective of this study was to investigate the tolerance of poultry and swine to dietary supplementation of a novel microbial-derived alkaline phosphatase (AP; E.C. 3.1.3.1 produced by Paenibacillus lentus strain CMG3709). Studies were conducted on day-old Ross 308 chicken (n = 1,000; Study 1) and weaned piglets (n = 180; Study 2) for a duration of 42 d; and consisted of four treatment groups (TG) based on the concentration of microbial-derived AP supplemented in their diet at 0; 12,000; 20,000; and 200,000 U/kg of feed. Parameters such as animal survival, hematology, coagulation, and biochemical indices were assessed at the end of the study. The effect of microbial AP on nutrient absorption through skin pigmentation and intestinal permeability were also investigated in broilers (n = 600; Study 3). In poultry (Study 1), there were no statistically significant differences between control and TG for any of the hematological and biochemical parameters, except for a marginal increase (P < 0.05) in serum phosphorus at the highest dose. This variation was not dose-dependent, was well within the reference range, and was not associated with any clinical correlates. In swine (Study 2), hematological parameters such as leukocyte, basophil, and lymphocyte counts were lower (P < 0.05) for the two highest doses but were traced back to individual variations within the group. The biochemical indices in piglets showed no significant differences between control and supplemental groups except for glucose (P = 0.0005), which showed a high effect (P = 0.008) of the random blood collection order. Nonetheless, glucose was within the normal reference range, and were not related to in-feed supplementation of AP as they had no biological significance. The survival rate in all three studies was over 98%. Dietary supplementation of microbial-derived AP up to 16.7 times the intended use (12,000 U/kg feed) level had no negative effects in both poultry and swine. In-feed supplementation of microbial-derived AP for 28 d improved intestinal pigment absorption (P < 0.0001) and reduced intestinal paracellular permeability (P = 0.0001) in broilers (Study 3). Based on these results, it can be concluded that oral supplementation of microbial-derived AP is safe for poultry and swine and effective at improving gut health in poultry.
      PubDate: Wed, 15 Jun 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac079
      Issue No: Vol. 6, No. 3 (2022)
       
  • Evaluation of dietary mycotoxin control strategies on nursery pig growth
           performance and blood measures

    • Abstract: AbstractA total of 4,318 pigs (337 × 1,050, PIC; initially 6.5 ± 0.08 kg) were used in a 35-day study to evaluate dietary mycotoxin control strategies on nursery pig performance and blood measures. Pigs were weaned at approximately 21 d of age and randomly allotted to 1 of 5 dietary treatments in a randomized complete block design with blocking structure including sow farm origin, date of entry into facility, and average pen BW. A total of 160 pens were used with 80 double-sided 5-hole stainless steel fence line feeders, with feeder serving as the experimental unit. For each feeder, 1 pen contained 27 gilts and 1 pen contained 27 barrows. There were 16 replications per dietary treatment. A common phase 1 diet was fed to all pigs in pelleted form for 7 day prior to treatment diets. Experimental treatments were fed from days 7 to 42 after weaning (days 0 to 35 of the study) and included a low deoxynivalenol (DON) diet (1.12 ± 0.623 mg/kg), high DON diet (2.34 ± 1.809 mg/kg), high DON+ 0.50% sodium metabisulfite (SMB), high DON+ one of two mitigating products; 0.30% Technology1, or 0.30% Technology1+. Technology1 and 1+ are comprised of clays, yeast cell wall components, and a blend of plant extracts. Technology1+ also contains SMB. Overall (days 0 to 35), pigs fed high DON had decreased (P < 0.05) final BW, ADG, and ADFI compared with low DON. Additionally, pigs fed high DON+SMB had increased (P < 0.05) ADG compared with all other treatments. An improvement (P < 0.05) in G:F was observed in pigs fed high DON + SMB or high DON + Technology1+ compared with the low DON or high DON + Technology1 diets with high DON diets intermediate. Pigs fed high DON + SMB or high DON + Technology1 diets had reduced (P < 0.05) total removals and mortality compared with pigs fed low DON diets with high DON and high DON + Technology1+ intermediate. Liquid chromatography/mass spectrometry analysis of circulating blood collected on day 35 revealed that pigs fed high DON or high DON + Technology1 had increased (P < 0.05) DON concentrations compared to low DON with high DON + SMB and high DON + Technology1+ intermediate. In summary, pigs fed high DON diets had reduced performance compared with pigs fed low DON. Sodium metabisulfite in high DON diets provided a benefit in growth performance with ADG and G:F exceeding growth performance in the low DON diet while, the improved G:F ratio combined with other immunometabolic changes (gamma glutamyltransferase and creatine kinase) associated with Technology1+ warrant further investigation.
      PubDate: Tue, 14 Jun 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac081
      Issue No: Vol. 6, No. 3 (2022)
       
  • The female to male calf sex ratio is associated with the number of
           services to achieve a calf and parity of lactating dairy cows

    • Abstract: AbstractCommercial dairy producers may get frustrated by the lower ratio of female to male calves born because female calves are more valuable than bull calves. Our objective was to determine if parity or stage of lactation at the time of breeding, using conventional semen, influenced the sex of the calf. Data from the University of Illinois and the University of New Hampshire dairy herds were collected and summarized for calf sex, the number of services to achieve a calf and the lactation number when conception of that calf occurred. Logistical regression procedures were used to analyze the dataset via version 9.4 of SAS. The final dataset contained 2,987 calvings, which consisted of 1,406 females and 1,581 males (47.1% and 52.9% for females and males, respectively). The frequency distribution of the number of services to achieve a calf was highest for the first service and progressively declined with increasing services (52.06%, 21.66%, 10.75%, 6.66%, 4.22%, and 4.65% for 1 to 6 services, respectively). The frequency distribution of calvings by lactation number was greatest for first lactation cows becoming pregnant with their second calf and declined with increasing parity (35.49%, 28.22%, 17.01%, 9.61%, 5.02%, 2.51%, 1.14%, 0.70%, and 0.30% for lactation numbers 1 to 9, respectively). Logistic stepwise regression indicated that the number of services to achieve a calf was significant in predicting the ratio of female to male calves. Calculation of odds ratios indicated that as the lactation number increased the likelihood of getting a bull calf decreased. Parity, services, and parity by services interaction were significant for cows having a greater number of parities and cows with a greater number of services yielding more heifer calves. However, an interaction occurred where cows with greater number of services along with greater parities more likely to have a bull calf. These data provide evidence that increasing the number of services to achieve a calf and increasing age of the cow increased the probability of a heifer calf being born. These data indicate that cows with greater parties (lesser cull rate) are more likely to produce heifer calves.
      PubDate: Tue, 14 Jun 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac080
      Issue No: Vol. 6, No. 3 (2022)
       
  • A porous ceramic particle with or without a preservative blend did not
           impair apparent digestibility of macro- and micro-nutrients of postweaned
           pigs

    • Abstract: AbstractThe objective of this study was to determine the effects of supplementing a commercial porous ceramic clay particle, with or without a blend of preservatives, on the performance and nutrient digestibility of weanling pigs. Fifteen weanling pigs of the Yorkshire, Landrace, and Duroc breeds were blocked by breed and randomly assigned to one of three treatments (n = 5): (1) Control, non-medicated diet with no additional feed additives (CON); (2) PowerGuard, basal diet with 0.25% of the DM consisting of a ceramic particle mixed into the pelleted feed (PG; MB Nutritional Sciences, Lubbock, TX, 79403); or (3) Power Guard + a blend of preservatives, basal diet with 0.3% of the DM consisting of the ceramic clay and preservatives mixed into the pelleted feed (PG-D). The facility was temperature controlled with an average temperature of 28.5 °C. Pigs were offered ad libitum access to feed and water and were housed individually in elevated crates. Body weights were collected upon enrollment on day 0 and at the end of the observation period on day 18. On day 15 , a 72-h total feed and fecal collection period began. Feed and fecal samples were analyzed for DM, CP, Ash, OM, ADF, NDF, zinc, copper, thiamin (vitamin B1), and retinol (vitamin A). Liver samples were collected immediately after harvest and frozen for later mineral analysis. Data were analyzed using Proc Mixed in SAS with dietary group as the main effect and block as the random effect (SAS 9.4, Cary, NC). There were no treatment differences in performance measures including final BW, ADG, or G:F (P ≥ 0.701). There were no treatment differences in diet nutrient digestibility for DM, CP, Ash, OM, ADF, or NDF (P ≥ 0.312). Additionally, there were no treatment effects on zinc, copper, or retinol digestibility (P ≥ .298); however, thiamin inclusion rate was increased for the PG-D treatment, thus leading to an increased digestibility for thiamin (P = 0.018) in the PG-D treatment. There were no treatment differences in hepatic mineral concentrations (P ≥ 0.532); however, there was a tendency for pigs fed PG-D to have increased hepatic concentrations of lead and mercury when compared with both PG and CON pigs (P ≤ 0.066). In summary, supplementation of a commercial ceramic particle with or without a blend of preservatives to weaned pigs did not affect performance or apparent nutrient digestibility.
      PubDate: Thu, 09 Jun 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac078
      Issue No: Vol. 6, No. 3 (2022)
       
  • Economic assessments from experimental research trials of feedlot cattle
           health and performance: a scoping review

    • Abstract: AbstractAnimal husbandry decisions for feedlot cattle may be based on economic or financial impacts reported from livestock research trials comparing interventions such as health practices or performance technologies. Despite the importance of economic assessments to production management decisions, there are no consensus guidelines for their methods or reporting. Thus, we hypothesized that methods and reporting of economic assessments in the scientific literature are inconsistent. This scoping review describes the types of economic assessments used to evaluate the costs and benefits of interventions in feedlot trials, how measured health and performance outcomes are utilized in economic evaluations, and the completeness of reporting. A structured search was used to retrieve peer-reviewed articles (published in English) on experimental trials performed in Australia, North America, or South Africa, which reported feedlot cattle health, performance, or carcass characteristics and included an economic outcome. A total of 7,086 articles were screened for eligibility; 91 articles (comprising 113 trials) met the inclusion criteria. Trial characteristics, methods, and reporting data were extracted. A primary outcome was stated in only 36% (41/113) of the trials. Of these 41 trials, an economic outcome was reported as a primary outcome in 18 (44%). Methodology for the economic assessment was reported for 54 trials (48%), the type of economic assessment was explicitly stated for 21 trials (19%), and both the type of economic assessment and methodology used were reported for 29 trials (26%); neither were reported for nine trials (8%). Eight types of economic assessments were explicitly reported: cost-effectiveness, cost–benefit analysis, enterprise analysis, partial budget, break-even analysis, profitability, decision analysis, and economic advantage. From the trials that did not report an assessment type, three were identified: partial budget, enterprise analysis, and gross margin analysis. Overall, only 32 trials (28%) reported economics as an outcome of interest, the methodology used or the type of assessment, and values, sources, and dates for at least some of the price data used in the analysis. Given the variability in methods and inconsistent reporting for feedlot trials identified by this scoping review, a guideline to facilitate consistency on appropriate methods and reporting is warranted.
      PubDate: Mon, 06 Jun 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac077
      Issue No: Vol. 6, No. 3 (2022)
       
  • Environmental performance of commercial beef production systems utilizing
           conventional productivity-enhancing technologies

    • Abstract: AbstractThe objective of this study was to evaluate the effects of using conventional productivity-enhancing technologies (PETs) with or without other natural PETs on the growth performance, carcass traits, and environmental impacts of feedlot cattle. A total of 768 cross-bred yearling steers (499 ± 28.6 kg; n = 384) and heifers (390 ± 34.9 kg; n = 384) were offered a barley grain-based basal diet and divided into implanted or non-implanted groups. Steers were then allocated to diets that contained either: (i) no additive (control); natural feed additives including (ii) fibrolytic enzymes (Enz), (iii) essential oil (Oleo), (iv) direct-fed microbial (DFM), (v) DFM + Enz + Oleo combination; conventional feed additives including (vi) Conv (monensin, tylosin, and beta-adrenergic agonists [βAA]); or Conv with natural feed additives including (vii) Conv + DFM + Enz; (viii) Conv + DFM + Enz + Oleo. Heifers received one of the first three dietary treatments or the following: (iv) probiotic (Citr); (v) Oleo + Citr; (vi) Melengesterol acetate (MGA) + Oleo + βAA; (vii) Conv (monensin, tylosin, βAA, and MGA); or (viii) Conv + Oleo (ConvOleo). Data were used to estimate greenhouse gas (GHG) and ammonia (NH3) emissions, as well as land and water use. Implant and Conv-treated cattle exhibited improvements in growth and carcass traits as compared to the other treatments (P < 0.05). Improvements in the performance of Conv-cattle illustrated that replacing conventional feed additives with natural feed additives would increase both the land and water required to satisfy the feed demand of steers and heifers by 7.9% and 10.5%, respectively. Further, GHG emission intensity for steers and heifers increased by 5.8% and 6.7%, and NH3 emission intensity by 4.3% and 6.7%, respectively. Eliminating the use of implants in cattle increased both land and water use by 14.6% and 19.5%, GHG emission intensity by 10.5% and 15.8%, and NH3 emission intensity by 3.4% and 11.0% for heifers and steers, respectively. These results demonstrate that the use of conventional PETs increases animal performance while reducing the environmental impacts of beef production. Restricting use would increase the environmental footprint of beef produced for both domestic and international markets.
      PubDate: Sun, 05 Jun 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac074
      Issue No: Vol. 6, No. 3 (2022)
       
  • Impact of protein supplementation on semen quality, fertility, and BMP1R
           gene expression in sheep of Bangladesh

    • Abstract: AbstractA study was carried out to know the impact of protein supplementation on fertility and expressions of the fertility gene BMP1R. Three International Organization for Standardization (ISO), isocaloric but different levels of protein supplement ration (11.70% crude protein [CP] for control/To, 12.99% CP for T1, and 13.86% CP for T2) were fed to three different groups of sheep. DNA was extracted from the whole blood sample for polymerase chain reaction (PCR) of the BMP1R fertility gene, and purified PCR products were sequenced by a Sanger sequencer. Sequence alignment, pair, and multi-alignment comparison of the BMP1R gene of the species were done with MEGA6. The semen volume (1.0 mL), sperm counts (4.2 × 107 million), and percentage of normal (94.3%) and viable sperm (3.7%) were higher in treatment 2 than in the other two groups. The semen volume (1.0 mL), sperm counts (4.2 × 107 million), and the percentage of normal (94.3%) and viable sperm (3.7%) were higher in treatment 2 than in the other two groups. Ewes treated with supplemented, protein concentrate reached the conception at an earlier age (treatment 1, 9.5 ± 0.16 mo and treatment 2, 10.3 ± 0.04 mo) than control (9.8 ± 0.15 mo). The lambing interval varied, from 198 to 202 d. Lamb’s birth weights in three treated groups were ranging from 1.2 to 1.39 kg. The designated sequences of BMP1R gene revealed 100% homology with the sequence of Kazakh sheep. The present study indicated that the influence of nutrition on reproductive performance and genomic study will be helpful for the genetic improvement of low-productive sheep.
      PubDate: Fri, 03 Jun 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac072
      Issue No: Vol. 6, No. 3 (2022)
       
  • Effect of a direct-fed microbial (10-G Armor) on feedlot performance,
           

    • Abstract: AbstractCrossbred beef heifers (N = 1,394; initial shrunk body weight [BW] 291 ± 9.9 kg) were used to investigate the efficacy of 10-G Armor (Life Products, Inc., Norfolk, NE; 10-G) upon feedlot performance, carcass characteristics, and fecal and subiliac lymph nodes Salmonella prevalence. Heifers were blocked by day of arrival and allocated to 1 of 20 pens (N = 70 heifers/pen) and assigned one of two treatments (10 pens/treatment): no direct-fed microbial (CON) or 2 g/heifer/d of Lactobacillus acidophilus, Enterococcus faecium, Pediococcus pentosaceus, Lactobacillus brevis and Lactobacillus plantarum, respectively (Life Products, Inc., Norfolk, NE; 10-G). Twenty-four animals were randomly selected from each pen for Salmonella sampling. Recto-anal mucosal swab samples (RAMS) were obtained at initial processing and harvest; subiliac lymph nodes were collected at harvest. In addition, pen surface fecal pats were collected and composited by pen (10 pats per composite, 5 composites per pen) on days 0, 52, 120, and 192. Data were analyzed as a generalized complete block design, and pen served as the experimental unit. No differences were observed in live growth performance metrics (P ≥ 0.55). Yield grade distributions did not differ between treatments (P ≥ 0.62); however, cattle fed 10-G tended (P = 0.06; 14.6% vs. 18.9%) to have fewer USDA Select carcasses and more (P = 0.09; 73.6% vs. 78.0%) USDA Choice carcasses. Cattle fed 10-G tended (P = 0.10; 9.2% vs. 12.3%) to have fewer liver abscesses and had fewer (P = 0.04; 5.3% vs. 8.5%) severe liver abscesses. Salmonella prevalence of RAMS did not differ between treatments at initial processing (P = 0.97; CON = 11.6%, 10-G = 11.5%) or at harvest (P = 0.91; CON = 99.0%, 10-G = 98.6%); however, RAMS differed (P < 0.01) in Salmonella prevalence between the two collection times. Cattle fed 10-G had a lower frequency of Salmonella positive lymph nodes (P = 0.01; CON = 15.8%, 10-G = 7.4%) than CON. However, Salmonella log (mpn/g) of lymph nodes did not differ between treatments at harvest (P = 0.34; CON = 0.73, 10-G = 0.34). These data indicate that cattle fed 10-G have decreased rates of severe liver abscesses without altering live animal performance or carcass characteristics. Supplementation of 10-G significantly reduced the prevalence rate of Salmonella recovered from the subiliac lymph nodes. The factors responsible for the observed difference in the effects of 10-G on Salmonella warrant further investigation
      PubDate: Thu, 26 May 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac073
      Issue No: Vol. 6, No. 3 (2022)
       
  • Invited review: strategic adoption of antibiotic-free pork production: the
           importance of a holistic approach

    • Abstract: AbstractThe discovery of the use of antibiotics to enhance growth in the 1950s proved to be one of the most dramatic and influential in the history of animal agriculture. Antibiotics have served animal agriculture, as well as human and animal medicine, well for more than seven decades, but emerging from this tremendous success has been the phenomenon of antimicrobial resistance. Consequently, human medicine and animal agriculture are being called upon, through legislation and/or marketplace demands, to reduce or eliminate antibiotics as growth promotants and even as therapeutics. As explained in this review, adoption of antibiotic-free (ABF) pork production would represent a sea change. By identifying key areas requiring attention, the clear message of this review is that success with ABF production, also referred to as “no antibiotics ever,” demands a multifaceted and multidisciplinary approach. Too frequently, the topic has been approached in a piecemeal fashion by considering only one aspect of production, such as the use of certain feed additives or the adjustment in health management. Based on the literature and on practical experience, a more holistic approach is essential. It will require the modification of diet formulations to not only provide essential nutrients and energy, but to also maximize the effectiveness of normal immunological and physiological capabilities that support good health. It must also include the selection of effective non-antibiotic feed additives along with functional ingredients that have been shown to improve the utility and architecture of the gastrointestinal tract, to improve the microbiome, and to support the immune system. This holistic approach will require refining animal management strategies, including selection for more robust genetics, greater focus on care during the particularly sensitive perinatal and post-weaning periods, and practices that minimize social and environmental stressors. A clear strategy is needed to reduce pathogen load in the barn, such as greater emphasis on hygiene and biosecurity, adoption of a strategic vaccine program and the universal adoption of all-in-all-out housing. Of course, overall health management of the herd, as well as the details of animal flows, cannot be ignored. These management areas will support the basic biology of the pig in avoiding or, where necessary, overcoming pathogen challenges without the need for antibiotics, or at least with reduced usage.
      PubDate: Mon, 16 May 2022 00:00:00 GMT
      DOI: 10.1093/tas/txac063
      Issue No: Vol. 6, No. 3 (2022)
       
 
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