Concentration of erythrocyte factors in cows with blood content up to 93.75% and higher in holstein breeds in the Experimental Station Streletskaya, Orel region

Marker-assisted selection is of great importance in dairy cattle breeding. The article analyzes the occurrence of erythrocyte factors in the herd of the breeding farm Streletskaya of the Federal Scientific Center of grain legumes in the herd of cows with the bloodline up to 93.75% and higher for Holstein breeds. To obtain information on blood groups, the data of the primary zootechnical accounting of the organization were used. The analysis of immunogenetic polymorphism was carried out on 96 heads of Black-and-White Holstein cows, which are currently classified as Holstein breed due to absorption. The studies were carried out on 11 loci of blood groups. The primary data were processed using the computer program "Microsoft Excel". It was found that the erythrocyte factors G2, Y2, Qʹ, X2 (63.5%) were in the EAB locus and Hʹ (69.8%) was in the EAS locus. The erythrocyte factors G1, G3, I, I1, O3, P1, Q1, Q4, Iʹ2, Jʹ, Gʹʹ2, X4, Uʹ, F2, Rʹʹ were rare. Their concentration was 1%. In cows with high milk yields (on average more than 7000-8000 kg of milk), combinations of alleles and were often encountered. The Lʹ antigen can be considered as markers of low milk yields with a certain degree of mutilation, the combination of BG antigens resulted in a decrease in milk yield and fat content, and C2 - in the protein content in milk. In this situation, it is advisable to recommend a more detailed study of the genealogy of cows with potential productivity markers, especially on the paternal side, in order to understand clearly which ancestor can be a carrier of such combinations. This knowledge will provide additional advantages in the selection of parental pairs.