Immunogenetic status and breeding value of Holstein cows

In the genealogical structure of the breeding stock, the highest specific weight is occupied by the Reflection Sovering and Vis bek Aydiala lines, accounting for 56.8 and 39.9% of animals, respectively. The study results of Holstein cattle blood-group factors can be used to monitor its gene pool, genetic intrabreed differentiation, assess selection parameters, and conduct targeted selection of parental pairs. It was determined that in EAA blood group system in Holstein cows of reproduction from the USA, the frequency of A1 antigen is 58.7%, and in domestic reproduction animals, this antigen is found with a lower frequency of 50.7%. At the same time, in the specified system of blood groups in both groups of experimental animals, antigen “a” is characterized by the highest frequency, the lowest occurrence is A2 antigen, and animals with A1 antigen took an intermediate position. In EAB system, the US Holstein cows have a higher frequency of such antigens as Е3/, О3 и I1 compared to the reproductive animals of Agro-Soyuz LLC. The EAF blood group system is represented by two antigens, where F antigen frequency in both groups of experimental animals is 100%. Of all the blood group systems, the greatest differences between compared groups of animals were detected for the antigens of EAZ blood group system