Identification of cattle fertility haplotypes

Abstract. An analysis of the reproduction rates of modern Holstein cattle populations has shown that one of the key factors influencing the decline in the reproductive qualities of cows are genetic factors. In recent decades, a large amount of data has accumulated on the presence in the genome of recessive mutations in the DNA sequence, which in the homozygous state reduce the reproductive functions of animals, causing embryonic mortality. The use of a limited number of outstanding sire bulls for artificial insemination has reduced the original genetic diversity. In this regard, the identification and determination of fertility haplotypes in populations has recently become an integral part of breeding work with cattle. Genotyping of 584 heads of Holstein cattle from 2 farms in the Sverdlovsk region was carried out in order to identify heterozygous carriers of anomalies: HH0 (FANCI), HH1 (APAF1), HH3 (SMC2), HH4 (GART), HH5 (TFB1M), HH6 (SDE2), HH7 (CENPU), HHB (ITGB2, BLAD), HHC (SLC35A3, CVM), RABGGTB, RNF20 and TTF1. The scientific novelty lies in determining the frequency of occurrence of fertility haplotypes that have not previously been studied in the Sverdlovsk region. The purpose of the study is to determine the frequency of occurrence of fertility haplotypes of Holstein cattle in populations of the Sverdlovsk region. Research methods. To diagnose mutations, we used test systems developed in the Laboratory of Molecular Basis of Breeding, Department of Biotechnology and Molecular Diagnostics of Animals, L. K. Ernst Federal Research Center. Results. The number of fertility haplotypes in the studied herds differed not only in the frequency of occurrence of the defect, but also in the number of types of detected haplotypes. In the population of “Kamenskoye” JSC, the largest number of animals were carriers of fertility haplotypes HH4 and HH3 with a carriage frequency of 1.891 and 1.412 %, respectively; the educational and experimental farm identified the largest number of haplotypes HH3 and HH6 with a carriage frequency of 4.082 %.