Abstract. To improve a structure of the Brown Swiss breed and promote valuable qualities of offsprings, it is necessary to take into account the breeding value of breeding families. Great results have been achieved in the herds of APC “Dobrovolets” in the Smolensk Oblast. The work is focused on identifying dependence of milk productivity of cows of the Brown Swiss breed on presence of alleles of EAB-locus of blood groups in the most promising families in breeding families. The scientific novelty lies in the fact that for the first time the Brown Swiss breed is characterized according to productive and genetic indicators. The above families comprise the study material. The study was carried out in 2017–2018 in the Laboratory for Immunogenetics of the Smolensk Agricultural Institute – Branch of the Federal Research Center of Fiber Crops, according to common methods, with the help of 52–65 reagents of own production, unified according to international standards. “Selex” system data are used for the analysis. 12 families with milk productivity averaging about 6,000 kg of milk, fat and protein content in milk averaging 3.86% and 3.30%, respectively, are identified. The breeding families of 27 cows (9.5%) have a yield of 7,000 kg of milk and above, from which it is possible to obtain calves for restocking the breed of the region. There were 5 key alleles with a frequency of more than 5%. Among them, alleles introduced into the population by Brown Swiss bulls of American breeding predominate. These data are consistent with previously published studies by other authors. The highest yield and fat content in milk is observed among animals, whose genotype has alleles G2E`2, O` and Q. These alleles can be considered as marker and taken into account in further breeding work. The research results used in the preparation of plans for breeding work with Brown Swiss breed in the breeding farms of the region. These results will be used in the research work under the research plan of the Smolensk Agricultural Institute – Branch of the Federal Research Center of Fiber Crops
Keywords
productivity, cows, blood groups, genotype, families, eav-locus alleles