FEATURES OF GENETIC DETERMINANTS IN UKRAINIAN POPULATIONS OF SIMMENTAL CATTLE

This article presents the results of a retrospective analysis of the genetic structure of herds of the introduced Simmental cattle breed using immunogenetic markers. Differences were established in the genetic structure between the Simmental breed population at PJSC “Chervonyi Veleten” Breeding Plant, which has been a part of the Ukrainian selection system for a long time, and the created population based on imported Simmentals from the breed’s countries of origin (LLC “Kramahrosvit” Breeding Reproducer, Donetsk region, Austrian selection). Immunogenetic testing of the cattle was conducted using 9 blood group systems and 60 antigens. In the studied groups of animals, 49 (“Chervonyi Veleten”) and 35 (“Kramahrosvit”) blood group system antigens were detected with varying frequencies. Twenty-seven instances of differences in erythrocyte antigen frequencies were recorded, characterizing the divergence between the studied Simmental breed populations. The largest number of differences was found in the EAB (16 antigens) and EAC (5 antigens) blood group systems. Within the EAB system, 13 erythrocyte antigens were detected that were absent in the study group from the “Kramahrosvit” breeding reproducer. Among these, antigens B2, G2, and O2 were observed in 23–27% of the breeding Simmental cattle at “Chervonyi Veleten”, A2/ and D/ in 14–18%, and the remainder in 2–10%. Within the EAC system, the antigenic factor C, occurring in 13.6% of Simmentals, is noteworthy. Antigenic factors EAB-Q, EAB-I1, EAC-R1, EAC-X1, and EAS-U// can be classified as lost in the “Chervonyi Veleten” population. Additionally, a significant decrease in the frequencies of antigens EAB-O1 (0.01 in “Chervonyi Veleten” cattle compared to 0.23 in “Kramahrosvit”) and EAS-S1 (0.14 versus 0.49, respectively) is observed. The changes in the set of erythrocyte antigens in the Simmental cattle at the “Chervonyi Veleten” breeding plant indicate a gradual deviation from the breed’s original gene pool. The retrospective analysis of blood groups in the studied animal populations confirms the necessity of genetic monitoring and the importance of maintaining a balance between improving productivity and preserving the genetic identity of breeds.