BoLA - DRB3 Gene Polymorphism and its Association with Lactation Yield and Milk Constituents in Crossbred Cattle

Abstract

The present study was undertaken to explore polymorphism at exon 2 of BoLA-DRB3 gene locus and its association with milk yield, fat % and protein % in a total of 40 Holstein-Friesian crosssbred cows using PCR-RFLP method. PCR-RFLP using Hae III restriction enzyme revealed presence of 7 genotypes with frequencies 0.475 (AA), 0.225 (AB), 0.050 (AE), 0.100 (BB), 0.050 (DD), 0.050 (EE) and 0.050 (II), respectively and PCR-RFLP using Bst YI yielded 3 genotypes with frequencies 0.050 (AA), 0.625 (AB) and 0.325 (BB), respectively. To study the association of BoLA-DRB3.2 genotypes with milk yield, fat and protein %, the data was subjected to analysis of variance employing general linear model using SPSS software package. Effect of farm (p less than 0.01) and parity (p less than 0.05) was significant on lactation yield; while the effect of season of calving, Hae III genotypes and Bst YI genotypes were non-significant. For fat % the effect of parity and season of calving was significant (p less than 0.05), while the effect of farm and genotype was non-significant. Milk protein % was significantly (p less than 0.05) influenced only by Bst YI genotype. Genotype AB recorded significantly higher protein % as compared to genotype BB.