Association of DGAT1, beta-casein and leptin gene polymorphism with milk quality and yield traits in Jersey and its cross with local Kashmiri cattle

This study investigated the impact and significance of polymorphisms in DGAT1, beta-casein and Leptin gene on milk quality and yield traits in Jersey and its local Kashmiri cross. A total of 200 animals were phenotyped for milk yield, fat content, protein content, fat yield and protein yield for a period of 305 days (January-October). The genotyping of animals for SNPs was done through PCR-Sequencing method. Three genotypes with respect to DGAT1-K232A polymorphism (KK, KA and AA) and only two genotypes of beta-casein (A1A2, A2A2) and leptin (CC, CT) gene were found in the studied population. In the association study K allele of DGAT1-K232A polymorphism was significantly associated with fat content, protein content and fat yield, whereas, A allele was correlated with protein yield and milk yield. A2 allele of beta-casein gene was found significantly associated with fat and protein content and A1 allele showed correlation with high protein and milk yield. On the other hand, C allele of leptin gene shows significant association with fat content only. The study suggests that the SNPs analyzed in this study associated with different milk traits and hence could be used as genetic markers for selection of dairy animals in breeding programs.