BLAD and CVM in the genetic structure of the cattle breeding stock in the Sverdlovsk region

Abstract

Abstract The identification of lethal and unwanted mutations in populations of black-and-white cattle breeding remains relevant, despite the fact that, in modern conditions, breeding bulls are being investigated for a wide range of known genetic anomalies. The broodstock not only of commercial farms, but also of breeding ones, remains not examined for mutations that are associated with economic losses due to the nonviability of the offspring and perinatal losses, the causes of which cannot be identified excluding infectious and alimentary factors. The genotyping of the broodstock carried out for the first time in the Sverdlovsk region confirms the presence in herds of mutant forms of the CD18 and SLC35A3 gene alleles in a latent state. In the studied herds, regardless of their breeding status, the carriage of BLAD and CVM anomalies is observed from 2.08% to 13.51% and from 2.70% to 7.55%, respectively. In some farms, carriage of two mutations reaches 16.21%. The results obtained demonstrate the prevalence of carriage of the studied alleles in most genealogical lines of bulls of the Holstein root. Thus, in the Vis Bek Aydial 933122 line, six daughters from six sire bulls were found to carry these mutant loci, in the Reflection Sovering 198998 lines in eight daughters from three sire bulls and in the Montvik Chief 95679 line in three daughters from three bulls. Lethal alleles of both genes were found in each line. In breeding organizations, it is necessary to conduct research on the carriage of lethal and unwanted genes, especially in a group of cows-mothers of replacement bulls, to prevent the spread of anomalies in the breed.