Elaboration of measures aimed at eliminating BLAD-carrier bulls of Ukrainian black-and-white dairy breed cattle

The purpose of the study is to estimate the frequency of bulls of the Ukrainian black-and-white dairy breed that are carriers of the recessive allele of the CD18 locus of cattle and to propose measures to reduce its prevalence. The analysis showed a high frequency of the recessive BLAD (BL) in the Ukrainian bulls belonging to Holstein-derived breeds. Lack of control over the spread of this hereditary congenital disorder has led to the uncontrolled use of BLAD carrier bulls. The the bovine CD 18 locus was conducted on 30 bulls of the Ukrainian Black-and-White dairy breed. It was found that 90% of bulls had the unaffected genotype at the CD18 locus (TL/TL), and 10% were heterozygotes (TL/BL) and could potentially spread the disease. As a result of studying the pedigrees and genotypes of animals, the authors propose measures to control the spread of the BLAD mutation in the dairy herds of Ukrainian Black-and-White dairy breed.