Influence of growth hormone gene polymorphism on the productive qualities and the level of toxic elements in the hair of Kalmyk breed calves

Abstract

The studies were performed on a model of calves of the Kalmyk breed (n = 100) from birth to 14 months of age. The effect of growth hormone polymorphism (rs135322669) on productive qualities, body parameters, and toxic load level is estimated. Blood samples were taken to detect gene polymorphism. DNA samples were isolated from whole blood using a DNA-Extran-1 reagent kit. Primers were developed based on published bGH sequences (Gen Bank Accession NOS. M57764) using Primer3 software. Real-time PCR was performed on an ANK-32 programmable amplifier. The frequency of occurrence of polymorphism in the calves was revealed: 62 % with the CC genotype, 26 % with CG and 12 % with GG. The study of the growth rate of the studied animals from birth to 14 months of age was carried out on the basis of individual monthly weighing. The development was studied on the basis of taking measurements: height at the withers, height at the sacrum, width of the chest, depth of the chest, length of the body, width at the sacrum at 14 months of age. The superiority of calves with CC genotype in live weight starting from 6 months of age over peers with genotypes CG and GG was established. At the age of 6 months it was 5.0–7.0 %, and at 14 months of age 5.0–9.0 %. Calves with the GG genotype were inferior to peers with the CC genotype in height at the withers by 2.3 %, by 2.0 % in the sacrum, by 4.7 % in the chest width, by 5.3 % in the width at the sacrum, by 3.1 % in the chest depth and were inferior to the calves with genotype CG by the width of the chest by 2.3 %. The determination of toxic elements: Al, Cd, Pb, Sn, Hg, Sr, was carried out by atomic emission and mass spectrometry (AES-ICP and MS-ICP). Calves with the SS genotype accumulated less toxic substances in the hair from the withers, so their ∑tox was 52.4-63.1 % lower as compared to their peers with the CG and GG genotypes. This is also confirmed by the correlation analysis, which revealed a reliable relationship between gene polymorphism and ∑tox in wool at the level of r = 0.92.