Identification and analysis of polymorphism of protein metabolism genes in Holstein cows

Introduction. Milk is one of the full-fledged food products, which is commonly called universal food. The supply of high-quality food products to the population of the country, including milk, is one of the most important issues of maintaining the health and food security of the population of any country, especially in the context of the geopolitical situation and import substitution. The purpose of the study was to identify and conduct PCR-PDRF analysis to study the polymorphism of kappa‒casein and beta-lactoglobulin protein metabolism genes in Holstein cows and to identify the relationship between these polymorphic gene variants with signs of animal dairy productivity. Materials and methods. Experimental studies and evaluation of genes carrying useful signs for dairy cattle breeding were carried out on 99 heads of cattle using PCR. The results of the research. The conducted genetic analysis showed that cows with the CSN3BBBLGAA genotype demonstrated the best milk yield, reaching an impressive 7340 kg, as well as protein yield, which amounted to 235.6 kg. Such cows were only 1.05 % of the total number studied. Animals with high milk protein content have also been identified – these are cows with the CSN3BBBLGAB genotype. The milk of these representatives has an impressive protein content of 3.36 %, which indicates their excellent performance in this parameter. Conclusion. Therefore, in order to succeed in breeding, it is necessary to use molecular genetic, DNA methods in breeding work, which will help to accurately determine the value of animals containing desirable complex genotypes in their genome and further accumulate them in the breeding core. The genetic code of each animal is unique, and with the help of DNA technologies, you can learn almost everything about animals - their predisposition to diseases, their ability to withstand high loads and recover quickly from injuries, as well as meat and dairy productivity and other important characteristics.