Аллелельная структура еав-локуса групп крови генофондной популяции холмогорского скота республики Коми

The ongoing metisation of Holstein cattle in Kholmogorskaya calls into question the continued existence of the breed and in the near future its gene pool will be lost, along with a number of adaptive and other economically useful qualities of these animals. Komi is one of the few regions where it was possible to preserve the population and breeding material of purebred and poorly holstinized Kholmogorsky cattle. Using data from breeding records in agricultural organizations of the Republic, a group of pure-bred and weakly holstinized (with a blood content of up to 25% for improving breed) Kholmogorsky cattle was identified (n=1034). In the selected animals, the immunogenetic method was used to determine the  nature of alleles of the EAV locus of blood groups, the frequencies of which were compared with the results obtained by other authors for Kholmogorsky and Holstein cattle. It was found that the selected gene pool has B-alleles A'O'2, E'G'G", OY2I', O1Y2I', B'E'2G', G3OTA'2'2F'2K', Q, B1G1O1Y2, B1I2Y1G'G", Q'Q', G", O2, which are absent in the Holstein breed. The OA',  G", GIA', BOY, BO, P1, E'G'Q', BO3YA'E'3G'P'Q'G", BGKE'F"2O' alleles frequently found in Holstein cattle were not found in Kholmogorsky cows. Alleles Y2A'2, O2'J '2K'O', G'G", G2Y2D', common among Holsteins, were less common in the studied population. In the studied gene pool, despite the greater number of EAV alleles, there is a more pronounced homozygosity (by 0.014), with a smaller number of effective alleles (by 2), compared to the results obtained for the Kholmogorsky breed in the 1980s. The selected group of cows highly preserved the pool of alleles characteristic of the ancestral Kholmogorsky population (r=0.834...0.863) and is of high value for supporting breeding and reproduction of the endangered breed.