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- The Role of Direct-Fed Microbes to Ruminants: A Review
Authors: Zemedkun Diffe, Tesfa Kassa
Pages: 1 - 13
Abstract: Feed additives are used in livestock feed and feeding to increase feed quality, the utility of feed derived from animals, and the performance and health of the animals. Digestibility gravies, rumen flora stabilizers, and microbial are some of the zoo's technological additions. Direct feed microbial are characterized as microbial-based feed additives, with a tighter definition than probiotics. It improves feed use by boosting energy usage per unit of feed and enhancing fiber digestibility. The term direct-fed microbial (DFM) was coined by the Food and Drug Administration and the American Feed Regulator Representatives Associations to describe a feed product that contains live, naturally occurring microorganisms such as bacteria, fungi, and yeast; the bacteria can produce or consume lactic acid. Microbial feed additives have traditionally been given to animals during stressful times in the hopes of establishing a beneficial microbe population in the digestive tract, which would reduce or prevent harmful organism development. DFM has several mechanisms of action, some of which affect the rumen and others which affect the gastrointestinal system. Lactic acid-generating bacteria (LAB) have a favorable impact on the rumen by reducing ruminal acidosis, encouraging the proliferation of ruminal microorganisms that have adapted to the presence of lactic acid in the rumen, and boosting lactic acid-using bacteria (LUB). LUB has been presented as a DFM that can lower lactate levels while maintaining ruminal pH. Through hydrophobic interactions, DFM can block or prevent pathogens like Escherichia coli from attaching to the intestinal mucosa. DFM medication helps dairy calves adapt quickly to solid feed by speeding up the formation of ruminal and intestinal microbes and preventing the spread of enteric pathogens, which can cause diarrhea. DFM was utilized to improve dairy cow performance by improving dry matter intake, milk output and protein content, as well as blood glucose and insulin levels before and after delivery. DFM is critical in beef cattle to prevent ruminal acidosis induced by highly fermentable diets, as well as to promote growth, meat output, and feed efficiency. Powders, pastes, boluses, and capsules are only some of the direct-fed microbial products available. It can be added to feed or ingested by drinking water. According to one study, feeding more than 107 CFU per head per day may cause lower nutrient absorption due to overpopulation in the gastrointestinal tract.
PubDate: 2022-06-18
Issue No: Vol. 10, No. 2 (2022)
- Estimation of (Co) Variance Components and Genetic Parameters of Growth
Traits for Boran Cattle
Authors: Dejenie Mengistie, Genet Zewdie, Tesfaye Sisay, Dereje Beyene, Selam Meseret, K Suk Kim, Hailu Dadi
Pages: 14 - 27
Abstract: Availing information on genetic parameters of traits of interest for a given population is a prerequisite for effective genetic improvement programs. The objective of this research was to estimate the covariance components and genetic parameters of birth weight (BW), weaning weight (WW), and growth rate (ADG) traits of Boran cattle maintained at Did Tuyera cattle breeding ranch. The total number of animals considered in this study was 1162 (634 males and 528 females). The fixed effects included in the animal model for the analysis of growth traits were calf birth year, season of birth, and sex of calf. Pedigree was pruned using Relax 2 program. Covariance components were estimated using the Average Information-Restricted Maximum Likelihood (AI)-REML procedure as implemented in the DMUV.6 program. The data for BW (1120), WW (1144), and ADG (1144) were collected between 1999 and 2005. The estimation of the BW, WW, and ADG of Boran's calves was optimized by evaluating two models that either include or exclude the maternal genetic effects. The best model was chosen according to the log-likelihood ratio tests. The genetic parameters were estimated using bivariate models (DMU) package, fitting univariate and bivariate models with a restricted maximum likelihood algorithm. The sex of the calf significantly influenced BW and ADG (p< 0.01). Calf birth year and birth season significantly (p< 0.001) influenced BW, WW, and ADG. The direct heritability estimates for BW, WW, and ADG were 0.17, 0.38, and 0.46, respectively. A larger phenotypic correlation coefficient was found between BW and WW (0.28). The direct and maternal genetic correlations for BW, WW, and ADG were -0.47, -0.45, and -0.47, respectively. The relatively high heritability estimates observed (model 1) for WW (0.38) and ADG (0.46) indicated that reasonable genetic improvement for those traits might be possible through selection.
PubDate: 2022-06-18
Issue No: Vol. 10, No. 2 (2022)
- Relationship between Fertility and Milk Production Traits in Pure Jersey
Dairy Cows: Multitrait Analysis
Authors: kefale getahun, Zenebech Lemma, Nibo Beneberu
Pages: 28 - 39
Abstract: Records on 22175 pure Jersey dairy cows evaluated the genetic and phenotypic correlations. Data for this study were collected from Adea Berga dairy research farm span over 33 years (1986-2019) performance records. Five fertility; number of services per conception (NSC), days open (DO), calving interval (CI), age at first calving (AFC), age at first service (AFS), and three-milk production traits; lactation milk yield (LMY), daily milk yield (DMY), lactation length (LL) were estimated by WOMBAT software fitted a multitrait repeatability animal model. The result of present study revealed that genetic correlations among fertility traits for pure Jersey cows varied from -0.63 to 0.91 whereas the values of phenotypic correlations were found to be ranged from -0.28 to 0.98. The AFS-AFC was the highest genetic and phenotypic correlations among all fertility traits. The lowest genetic and phenotypic correlations were between AFS/AFC-CI and AFS/AFC-NSC, respectively. For milk production traits, the genetic correlations ranged from 0.86 to 0.96 whereas the values of phenotypic correlations were found in the range of -0.05 to 0.82. The LMY-LL was the highest genetic and phenotypic correlation and DMY-LL was the lowest. The genetic correlations between reproductive and milk production traits also varied from -0.38 to 0.42 and phenotypic correlations ranged from 0.13 to 0.48. The highest genetic and phenotypic correlations for reproductive and milk production traits were from DO-LL and LMY-CI/DO whereas the lowest was from NSC-LL and AFS-LL, respectively. Genetic correlations among the traits in the present study were higher than the corresponding phenotypic correlations among all milk production traits and the majority of fertility traits. The positive genetic correlations among traits in the present study would broaden the choice selection of more traits at one time for improvement. To improve genetic progress and breeding efficiency of Jersey dairy cows, periodic evaluation of the genetic and phenotypic relationship of dairy traits should be applied and more than one trait should be selected based on the magnitude of correlations (more correlated traits).
PubDate: 2022-06-19
Issue No: Vol. 10, No. 2 (2022)
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