seyed mohammad reza beheshti; kamran rezayazdi; arya badiei; Mostafa Sadeghi
Volume 23, Issue 2 , July 2021, , Pages 213-221
Abstract
The aim of this study was to investigate the effect of different levels of live yeast on ruminal function and health of dairy cows fed diets containing low and high concentrations of non-fiber carbohydrates (NFC). In this experiment, six cannulated dairy cows were randomly assigned in a Latin square ...
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The aim of this study was to investigate the effect of different levels of live yeast on ruminal function and health of dairy cows fed diets containing low and high concentrations of non-fiber carbohydrates (NFC). In this experiment, six cannulated dairy cows were randomly assigned in a Latin square design with six periods (14-days) and six treatments including 1- diet contain low NFC free of live yeast, 2-diet contain low NFC with 5 g/d of live yeast, 3-diet contain low NFC with 10 g/d of live yeast, 4-diet contain high NFC free of live yeast, 5-diet contain high NFC with 5 g/d of live yeast and 6-diet contain high NFC with 10 g/d of live yeast. Dry matter intake, rumination, ruminal parameters and blood metabolites were determined in the different periods. Dry matter intake, rumination activity, nutrient digestibility, mean ruminal pH and temperature were not affected by treatments. General and plasma indicators of animal healthwere also not affected by treatments. Overall, the results of this experiment indicated that dietary supplementation with live yeasthad no significant effect on rumen function and health in cows fed diets containing different concentrations of NFC.
Behzad Rajabi Marand; Hossein Moradi Shahrbabak; Mostafa Sadeghi; Rostam AbdolahiArpanahi
Volume 21, Issue 4 , January 2020, , Pages 419-430
Abstract
The aim of current study was to evaluate the accuracy of genomic breeding values (GEBV) for two important economical traits of milk yield and somatic cell score using SNP markers and LD-based haplotype blocks (haploblocks) by two statistical methods of GBULP and Bayes B. The data set consisted ...
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The aim of current study was to evaluate the accuracy of genomic breeding values (GEBV) for two important economical traits of milk yield and somatic cell score using SNP markers and LD-based haplotype blocks (haploblocks) by two statistical methods of GBULP and Bayes B. The data set consisted of 1654 bulls genotyped with different marker densities. When SNPs were used, the accuracy of breeding values obtained by Bayes B was better than GBLUP. In other words, for milk yield and somatic cell score traits, the prediction accuracy of GBLUP was 0.54 and 0.44 and by Bayes B was 0.58 and 0.44,respectively. For milk yield, the prediction accuracy of using haploblocks in both statistical methods was higher than the prediction accuracy using SNPs, while for the somatic cell score, this increase was more pronounced when GBLUP was used. However, when Bayes B was used this superiority was only obtained when the r2 statistic used to build the haploblocks was higher than 0.2. The results showed that the optimum level of r2 for building haploblocks depends on the trait type and its heritability. As a result, using r2 statistic more than 0.2 for building haploblocks can increase the accuracy of breeding valuesfoe both traits compared to SNP markers.