Genes polymorphism of beta-casein (CSN2) and kappa-casein (CSN3) in dairy cattle (review)

Milk productivity is a quantitative and qualitative indicator that results from the interaction of the animal’s genotype and environmental factors. The main aim of dairy farming is to optimize milk production, and the selection and reproduction of animals with the most desirable genotypes serve as the basis for any selection process associated with the genetic improvement of them. Cow’s milk contains four different types of caseins: alphaS1-, alphaS2-, beta- and kappa. These variants are expressed by autosomal codominant genes with multiple allelic variants and are all located on chromosome 6. Studying the effect of milk protein polymorphisms on milk production will allow a better understanding of its genetic components. The purpose of the work was to summarize the scientific material on the polymorphism of beta-casein (CSN2) and kappa-casein (CSN3) genes in dairy cattle, obtained by domestic and foreign scientists in recent years of DNA research. The literature review has been presented by the analysis and generalization of scientifi c data obtained on the problem under study. When preparing the analytical review, the search for material was carried out in the following databases: Elibrary, GoogleScholar, cyberleninka and cnshb. Thirty three 33 literary sources were analyzed, which was an indicator of a deep analysis of the situation on the problem under study. The analysis showed that in different regions of the Russian Federation studies were being conducted on the identification and real use of the CSN2 and CSN3 genes in the selection process to improve the protein characteristics and technological properties of milk. The data presented indicate the presence of a correlation between the fat and protein content in cows’ milk with different allelic states of the marker genes under consideration.