Polymorphism of the kappa-casein gene in the dairy cattle population of the Omsk region

The aim of research is to study the polymorphism of the kappa-casein gene in the dairy cattle population of the Omsk Region. The object was the herd of cows (n = 400) of the Black-and-White breed, which constituted selection groups in the breeding farms of the Omsk Region. Genetic analysis of the samples was carried out using PCR diagnostics of each DNA sample. For the kappa-casein gene in the studied breed, the frequency of heterozygotes was 0.40. The values of the other two genotypes varied from 0.12 to 0.48. In the population of dairy cattle of the Black-and-White breed, the B/B genotype was found with a frequency of 0.12. The main part of the herd - 52 % of cows carry the allele associated with milk protein content. Animals with the A/A genotype exceeded their peers in milk yield by 503 kg, or 8.05 %, and were distinguished by maximum milk production (P