USING A MARKER-BASED SELECTION IN BREEDING OF DAIRY CATTLE OF DIFFERENT BREEDS

Dependence on imports of main food products remains unchanged in the Russian Federation. Government programms set goals to increase quantity as well as quality of manufactured products. It is possible due to the introduction of a DNA technology into dairy cattle breeding. Reliable genetic markers of a cow protein milk ability are kappa casein and beta-lactoglobulin. We have studied milk proteinpolymorphism, genotype combinations in interconnection with milk ability and breed for the Ayrshire, Holstein and Holstein-Yaroslavl cross breed cows. It was found that in the same conditions and with the balanced feeding differences in milk yield and quantity of fat in milk among breeds are statistically unreliable while in milk protein quantity the difference is highly reliable D ≥ 0,999. There is high occurrence frequency of A kappa casein allele (0,74– 0,93) and low of kappa casein allele B (0,07–0,12), especially in case of the Ayrshire breed. B-allele of beta-lactoglobulin in the genotype of all cows is seen with the frequency of 0,58–0,70, A-allele is average (0,30–0,42). In order to increase the protein milk ability of the cows farms are to use more Ballele kappa-casein servicing bulls. Target breeding according to this characteristic as well as milk yield is also recommended.