DOI: 10.36871/vet.zoo.bio.202109007
UDC 636.22 / 28.082

Authors

E. N. Vasilyeva
Candidate of Agricultural Sciences, Senior Researcher of the Laboratory of Genetics and Breeding of Ayrshire Cattle Russian Research Institute for Farm Animal Genetics and Breeding – Branch of the L. K. Ernst Federal Science Center for Animal Husbandry, Pushkin, Russian Federation

Abstract

In recent years, after the import of cattle and sperm of Ayrshire bulls from abroad, cases of the transfer of the AH1 haplotype carriage to bulls and cows in our herds have been recorded, which can negatively affect at the breeding value of animals. Fertility haplotype AH1 is an autosomal monogenic genetic defect inherited in a recessive manner. Information on the identification of the AH2014 fertility haplotype in Ayrshire cattle has become available in foreign scientific sources since 1. Studies of the influence of the AH1 haplotype on the breeding qualities of the Ayrshire bulls of RF were carried out on 73 tested bulls, of which 16 are carriers of this genetic defect (AH1C), and 57 are free (AH1F). In one-way analysis of variance, it was found that the factor of the carrier status of the fertility haplotype (36,7%) has the greatest influence on the BV of bulls of milk yield, then «the number of male AH1C ancestors in all ranks of the pedigree» – 16,8%, and then the factor «nearest rank of pedigree with a male ancestor АН1С» – 13,9%. It was found that among carriers of AH1 the number of bulls improving milk yield over +100 kg is significantly less compared to the group free from the haplotype (6,3% instead of 40,4%, respectively). The proportion of bulls with BV of milk yield over +100 kg sharply decreases with an increase in the AH1C ancestors from 1 to more than 3, as well as when the first AH1C ancestor approaches the proband. In order to control the spread of the AH1 fertility haplotype, when choosing bulls, it is advisable not to admit male ancestors in their pedigree – carriers of this genetic defect closer to the 1 rank, and also to avoid the accumulation of more than three AHXNUMXC males in all ranks of the pedigree.

Keywords

Ayrshire breed, AH1 fertility haplotype, ancestors, pedigree, bull, BV, AHXNUMXC, milk yield, proband.