Kafkas Üniversitesi Veteriner Fakültesi Dergisi 2020 , Vol 26 , Issue 5
Meta Analysis of Allele and Genotype Frequency of Growth Hormone (bGH) Gene AluI Polymorphism, Which is Effective on Milk Yield in Holstein Cattle
Aytaç AKÇAY1, Fadime DALDABAN2, Elif ÇELİK3, Korhan ARSLAN2, Bilal AKYÜZ2
1University of Erciyes, School of Veterinary Medicine, Department of Biometry, TR-38280 Kayseri - TURKEY
2University of Erciyes, School of Veterinary Medicine, Department of Genetics, TR-38280 Kayseri - TURKEY
3University of Erciyes, Graduate School of Health Sciences, Department of Animal Science, TR-38280 Kayseri - TURKEY
DOI : 10.9775/kvfd.2020.24256 There are studies investigating the relationship between bGH gene AluI 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-AluI genotype and allele frequencies in Holstein breed by meta-analysis method. The study material consisted of studies investigating bGH-AluI 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 VV) 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 VV 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-AluI polymorphism genotype and milk yield in Holstein cattle with meta-analysis. Keywords : AluI, bGH gene, Holstein, Meta analysis, Milk yield