The influence of different genotypes of kappa-casein and beta-lactoglobulin on the productivity of cows of Ayrshire, Holstein and Yaroslavl breeds

Abstract

Under the conditions of intensification of dairy cattle breeding, genetic markers of protein-milk content, namely allelic variants of kappa-casein and beta-lactoglobulin, are increasingly used. They are established by the method of DNA testing on blood samples of breeding animals. This method is also being introduced in our country, which is especially important when selecting breeding sires for the artificial insemination network. The purpose of the research was to study the quality indicators of milk of cows bred in the region of breeds (Ayrshire, Holstein, Yaroslavl), and the protein-milk product produced from it as cottage cheese, depending on the influence of the genotype. The research has been carried out in CJSC “Agrofirma “Pakhma” in the Yaroslavl region. The object of research was cows of Ayrshire, Holstein and Yaroslavl breeds. The sample included 99 cows, including 36 animals of Ayrshire breed, 33 Holstein and 30 Yaroslavl breed. A comparative comprehensive evaluation of the dairy productivity of cows of Ayrshire, Holstein and Yaroslavl breeds under the conditions in one herd using DNA testing has been carried out, for the entire productive period of economic use, the realization of the genetic potential has been traced. For the first time in the Yaroslavl region DNA testing of Ayrshire cows was carried out and new data on the polymorphism of the CSN3 and LGB genes in Holstein and Yaroslavl cows were obtained. The association of CSN3, LGB genotypes and complex genotypes with milk productivity and technological properties of milk has been investigated. The yield and quality of cottage cheese from the milk of cows of different breeds in association with CSN3 genotypes have been studied. As a result of studying the quality indicators of milk of cows of different breeds and the protein-milk product produced from it as cottage cheese, depending on the influence of the genotype. It has been found that cows of different breeds and different genotypes had significant differences in the quality of milk and cottage cheese produced from it, which must be taken into account when conducting breeding work with these breeds.