MOLECULAR GENETIC MONITORING OF RED‑AND‑WHITE COW BREED

Abstract

Scientifically based breeding work in cattle breeding, including the analysis of breed resources, the study of genetic and phenotypic traits, as well as the creation of a highly valuable gene pool, is a key factor in the intensification of beef and dairy farming. One of the urgent problems of modern breeding is the genetic erosion of local breeds, in particular Red‑and‑White dairy breed. This process is a consequence of the large-scale use of Holstein stud bulls in breeding programs, which are aimed at accelerating genetic progress. In the present study, a comprehensive approach was applied that integrated traditional breeding methods with modern molecular genetic technologies. A genetic certification of Red and White dairy breed was carried out with the verification of breed affiliation and identification of allelic variants of the STAT1, STAT3 and STAT5A genes associated with reproductive function. The study of polymorphism of these genetic markers is of particular interest in the context of solving the problem of low fertility, which has a significant impact on the economic efficiency of dairy farming. The experimental part of the work included genotyping of first-calf heifers of domestic breeding at enterprises of the Voronezh Region, followed by analysis in a specialized laboratory of LLC “Miratorg-Genetics”. The results of the molecular genetic examination demonstrate significant genetic polymorphism in the studied population. It was found that 50.5% of individuals (156 head) were characterized by a blood ratio of less than 75% of the Holstein breed, which met the criteria for classification as purebred Red‑and‑White cattle according to current regulatory documents. The established genetic heterogeneity of the population determines the expediency of applying a stratified approach to the management of breeding programs in dairy cattle breeding. The implemented molecular genetic monitoring using DNA diagnostic methods revealed the presence of a significant allelic load in the studied livestock. The identified polymorphic gene variants are associated with reproductive status disorders, which actualizes the introduction of a genomic selection system to optimize economic performance. The obtained results justify the regular identification of genetic risks in order to preserve the breeding potential of domestic breeds in the context of the transformation of modern animal husbandry systems.