Dairy productivity and milk quality composition of cows with different GPX-1 genotypes

The glutathione peroxidase-1 (GPX-1) gene is responsible for the antioxidant system of the organism under oxidative stress and protects biomolecules from damage. The aim of this work was to study the association of glutathione peroxidase-1 (GPX-1) gene polymorphism with milk productivity and milk quality composition of Holstein cattle. The experiment was conducted on two populations of Holstein cattle of the Republic of Tatarstan - in Mukhametshin Z.Z. PFE Sabinsky district - 231 cows of foreign selection and in the Lenin Breeding Farm IAPC of Atninsky district -148 cows of domestic breed. DNA testing revealed the following distribution of alleles and genotypes: T (0,497) and C (0,503), three genotypes - CC (20,3 %), TC (60,1 %) and TT (19,6 %) in the population of domestic cattle; alleles C and T - 0,513 and 0,487, genotypes - CC (23,0 %), TC (56,7 %), TT (20, 3 %) in cattle of foreign selection. It was found that in both populations animals with genotypes CC and TC had high indicators of milk yield for 305 days, milk yield coefficient and lactation stability. In the cattle of foreign selection, the high level of fat mass fraction, milk fat and protein yield was found in cows with CC genotypes. The cows of domestic selection, having genotype TC, favorably differ in the indicators of qualitative composition of milk. The increased somatic cell content in milk, both in the first and in the second population, is observed in animals with TT genotype. The results of the study indicate that carriers of allele C of the GPX-1 gene may be useful in breeding to improve the population of Holstein cattle for breeding traits associated with resistance of lactating dairy productivity of cows to oxidative stress, capable of maintaining high dairy productivity in combination with high milk quality.