Polymorphism of the kappa-casein gene in dairy cattle populations of the Kostroma region and its effect on dairy productivity of cows

Relevance. Despite the more than 20-year history of research, the study of the polymorphism of the kappacasein (CSN3) gene in domestic dairy cattle breeds and its effect on the indicators of dairy productivity of cows is still relevant. The largest number of domestic studies on the kappa-casein gene was carried out on the Black-and-White and Yaroslavl breeds, while the Kostroma breed of dairy cattle in this area has not been studied enough.Methods. The source of DNA for analysis was whole blood taken from the tail vein of animals and treated with a set of reagents "Proba-NK" ("NPO DNA Technology" LLC, Russia) according to the manufacturer’s instructions. Genotyping of the single-nucleotide polymorphism of the kappa-casein gene (rs43703017) was implemented by real-time PCF using the "DTprime" amplifier ("NPO DNA Technology" LLC, Russia) and HRM-analysis technology (high resolution melting). The results were processed using methods of zootechnical and statistical studies.Results. As a result of the study, it was found that the population of cows of the Kostroma breed is characterized by a significantly greater consolidation of the gene pool compared to animals of the Blackand-White breed, which suggests a higher efficiency of breeding work with the Kostroma breed using the kappa-casein gene as a genetic marker of suitability of milk for cheese making. The kappa-casein gene has a significant effect on the parameters of dairy productivity and functional longevity of cows. 