The use of modern biotechnology of reproduction to improve the Hereford gene pool

Abstract

The gene pool improvement of North Caucasian population is carried out through artificial insemination of herds with sperm from sires carrying the desired alleles of genes associated with meat productivity and beef quality. The frequency of homozygotes in CAPN1 gene was found in Stavropol population of Hereford sires: CC – 6 %, GG – 88 % and more. This indicator was 50.0 % in the LL genotype of somatotropin gene (GH), which is 22-28 % more than that in hetero and homozygotes LV and VV. The frequency of CC genotype was 61 % higher in TG5 DNA-marker than that of the heterozygous CT form. The use of modern biotechnological methods of herd reproduction made it possible to reduce the degree of homozygosity in CAPN1 and TG5 genes by 28.8% and by 18.1% in the next generation. The homozygosity degree in CAPN1 and TG5 genes were less by 28.8 % and 18.1 % in progeny than that in sires. However, the number of effective alleles was higher by 0.53 % and 0.41 % for CAPN1 and TG5 SNP markers in progeny bulls. The observed heterozygosity varied in the range of 0.281-0.344 for gene markers CAPN1, GH and TG5 in the sire group. A high genetic similarity was established between sires and progeny – an average of 0.973. This indicator was 0.999 and 0.970 for GH and TG5 gene-markers. The largest genetic distance was determined in CAPN1 gene – 0.044. Thus, the high plasticity of the gene pool in North Caucasian Herefords population has been proved under the influence of a targeted mating system of parental pairs based on the improvement of herd reproduction biotechnology. The progeny bulls from sires-carriers of the desired alleles had an advantage over peers in growth rate at the age of 3-7 months and 12-15 months, it amounted to 163.9 g (17.7 %; P <0.05) and 160.3 g (14.5 %; P <0.05) respectively.