Akademik Veri Yönetim Sistemi
KAFKAS UNIVERSITESI VETERINER FAKULTESI DERGISI, cilt.26, sa.5, ss.687-695, 2020 (SCI-Expanded)
There are studies investigating the relationship between bGH gene Alul polymorphism and milk yield in bovine breeds. In the presented study, the relationship between different genotypes and lactation milk yields was determined by analyzing bGH-Alul genotype and allele frequencies in Holstein breed by meta-analysis method. The study material consisted of studies investigating bGH-Alul polymorphisms that are effective on milk yield in Holstein breed. According to the determined criteria, allele and genotype frequencies of 4583 samples in 20 studies selected from 35 studies and milk yields of 932 samples in 6 studies in which milk yields were calculated according to genotypes were included in the meta analysis. In the study, meta analyzes LL, LV and VV genotypes and L and V alleles and lactation milk yields were performed for bGH gene. The study samples were proved to be unbiased with the Begg and Mazumdar Rank Correlations test and funnel plot. As a result of the study, high heterogeneity was determined between the investigated studies concerning all genotypes (LL, LV and W) and allele frequencies (L and V), thus random effect model was used. Meta analyzes were done with Comprehensive Meta-Analysis Software (CMA). According to the random effect model, pooled ratios in LL, LV and W genotypes are 0.710, 0.260 and 0.030; pooled ratios for L and V allele frequencies were calculated as 0.818 and 0.182 and were found statistically significant (P<0.001). In addition, mean milk yields in LL, LV and VV genotypes were calculated as 6.64, 6.96, 7.13 L x1000 according to meta-analysis and subgroup analysis results, but no significant difference was found (P=0.958). At the end of the study, closer results to the population parameter were obtained regarding the relationship between bGH-Alul polymorphism genotype and milk yield in Holstein cattle with meta-analysis.