INFLUENCE OF -824 A/G POLYMORPHISM IN THE TUMOR NECROSIS FACTOR-ALPHA GENE ON MILK PERFORMANCE TRAITS IN RED STEPPE CATTLE

Abstract

The influence of -824 A/G polymorphism in the TNF-a gene on milk performance traits in Red Steppe cattle was studied. The tumor necrosis factor-alpha (TNF-a) gene encodes a pleiotropic cytokine that plays a critical role in immune response and mammary gland development. Recently, it was found that TNF-a -824 A/G gene polymorphism in cattle is associated with recovery of ovarian activity postpartum and with the reproductive efforts of cows over the course of lactation events depending on the sex of progeny. Among the 148 animals sampled, genotype frequencies of G/G, G/A, and A/A were 56, 38, and 6%, respectively, where frequency of allele G was 75%, and frequency of allele A was 25%. Milk yield, milk fat yield, and milk protein yield for third lactation were significantly higher in heterozygotes G/A compared to G/G homozygotes (10%, 9%, and 11%, respectively). No significant associations were found for other milk performance traits (milk yield, milk fat yield, and milk protein yield for first lactation, highest lactation, and average yield for all lactations).