Effect of Leptin Gene Polymorphisms on Milk Production Traits of Jersey Cows

A total of 181 Jersey cows were used to investigate how leptin gene polymorphisms affect milk production traits such as milk yield, fat and protein yield, and fat and protein content. Two single-nucleotide polymorphisms (SNPs) were genotyped, including the A59V in exon 3 and Sau3AI in intron 2. The genotype, allele, and haplotype frequencies were estimated. Statistical analysis revealed that the A59V polymorphism significantly affected the milk, protein, and fat yield (P <= 0.01, P <= 0.05, respectively) with C as a desirable allele. No associations were observed between the Sau3AI polymorphism and the traits analysed in this study. However, cows with the CC/TT haplotype were characterised by a significantly lower milk fat content compared with cows with other haplotypes. The results indicated that selection for the A59V CC and CT animals might contribute to increase in milk yield as well as fat and protein yields in Jersey cattle.