Association of CAPN1 and GH genes with productivity traits in Kazakh Whiteheaded cattle

The Kazakh Whiteheaded cattle was developed by crossing local breeds with the Hereford breed in Kazakhstan in the 30s of the last century. This breed is adapted to arid conditions of extreme continental climate. The goal of the investi-gations was the assessment of the genetic structure of the Kazakh Whiteheaded breed based on the genes of calpain (CAPN1 ) and somatotropic hormone (GH ) and analysis of the association of genotypes for these genes with productivity traits. The main argument for this aim is research works illustrated that both genes could affect on meat productivity traits in other breeds of cattle. 352 blood samples from representatives of Kazakh Whiteheaded animals of different sex and age groups were genotyped for the CAPN1 and GH loci. As a result, it was firstly proved that Kazakh Whiteheaded animals, who are CC homozygosis at the CAPN1 locus and VV homozygosis at the GH locus, reliably exceed animals without C and V alleles on the productivity traits such as milk production, average daily body weight gain, and pre-slaughter body weight, slaughter weight, carcass weight, flesh weight, chemical composition and histological characteristics of meat. It was also shown that the frequencies of the desired alleles and genotypes of these loci are rather low the frequency of the C allele was 0.11–0.17, and the frequency of the CC genotype was 0.03–0.06 in different age and sex groups; the frequency of the V allele was 0.19-0.40, and the frequency of the VV genotype was 0.03-0.31. Thus, planning selection for Kazakh Whiteheaded cattle, it would be useful to take into account the assessment of ani-mal genotypes at the CAPN1 and GH loci to increase the proportion of animals with the desired genotypes.