Polymorphism of the DNA in the Yaroslavskaya breed of the cattle according to the gene of kappa-casein

Molecular-genetic characteristic of the cattle of the Yaroslavl breed in the farm of the JSC «Mihailovskoe» situated in the Yaroslavl region was studied according to the gene of kappa-casein (CASK).The Yaroslavaskaya breed is considered to be the most genetically heterogenous among the other breeds. At present five diagnosed alleles of the kappa-casein gene were detected in the breed. The Yaroslavskaya breed (pure breed animals and animals of the Mihailovskii type) raised in the herd of the JSC «Mihailovskoe» is of great value for selection practice as a carrier of the valuable from the ecomonic point of view B-allele of the kappa-casein. Analysis of the genetic structure of the population demonstrated predominance of the A allele (0,60) of the kappa-casein gene over the B allele (0,40) in the pure breed animals and 0,80 and 0,20 correspondingly in the animals of the Mihailovskii type. The pure breed heifers of the Yaroslavskaya breed with kappa-casein BB are characterized by high yields and really the highest fat and protein contents that exceed average fat and protein levels in the milk of the cows with genotypes AA and AB by 273,155 kg of milk, 0,10,0,09% fat and 026,0,04% protein correspondingly. Cheese manufacturing from the milk produced by the cows with the BB genotype appeared to be most efficient as compared with cheese manufacturing from the milk received from the cows of the genotypes AA and AB. The highest level of profitability was achieved at production of cheese from the milk of the pure breed cows with the genotype BB -86,83% and the lowest was noted when the milk of the animals with genotype AA (71,80%) was used. The highest level of profitability was received at production of cheese from the milk of the cows with the genotype AA - 123,72% and the lowest profit was observed at cheese production from the milk of the AB genotype cows -80,69%. It is offered to make the DNA-testing of cows and breeders by the kappa-casein genotype in order to apply genetic markers for protein content increasing and improvement of cheese suitability of milk.

cattle, the Yaroslavskaya breed, genetic marking, polymorphism of the kappa-casein gene, milk composition