The Ayrshire dairy breed is renowned for producing large quantities of high quality milk and, therefore, is frequently used for crossbreeding. However, various hereditary anomalies caused by gene mutations have been recently recorded in calves produced by some Ayrshire sires. Most of these anomalies were shown to have a recessive inheritance pattern, thus imposing a threat of unpredictable dramatic changes in cattle genotypes under such factors as genetic drift, selection and inbreeding. The purpose of this study was to examine the susceptibility of the Ayrshire cattle bred in the North Caucasus to such hereditary abnormalities as complex vertebral malformation (CVM) and bovine leukocyte adhesion deficiency (BLAD). The investigation was carried out on 16 cows with various phenotype and reproduction disorders that were selected based on a three-year veterinary observation of 440 livestock animals. The target group cows were generally the descendants of Hannulan Yaskiyri, Riihiviidan Urho Errant and O.R. Lihting. The results demonstrated that no animals under study were the carriers of these genetic disorders, which proved the mutant alleles of BLAD and CVM to be absent from the Ayrshire cattle livestock bred in the North Caucasus. Therefore, the sires of these cattle can be successfully used for breeding.
DETECTION OF BOVINE LEUKOCYTE ADHESION DEFICIENCY, DEFICIENCY OF URIDINE MONOPHOSPHATE SYNTHASE, AND COMPLEX VERTEBRAL MALFORMATION IN HOLSTEIN CATTLE
