Reducing the modifying impact of the ecological factor at breeding value assessment of Hereford bull calves taking into account phenotype and complex of genes GH and GDF5

Abstract

The objective assessment of beef cattle genetic potential is a priority task of beef cattle breeding intensification. The purpose of the study was to test a method for reducing the modifying effect of ecological factor in assessing the breeding value of Hereford bulls based on combined selection, taking into account the phenotype assessment and genotyping by GH and GDF5 genes. For this purpose, the bull calves were tested according to productivity in two variants: 1) setting and selection of young cattle for control cultivation on the basis of phenotype (traditional assessment); 2) traditional selection was supplemented by genotyping assay for the complex of GH and GDF5 genes. The individuals with desired allelic profile (genotypes VV and VL of GH gene and genotypes TT and TC of GDF5 gene) showed increased weight gain intensity relative to their herd mates. The analysis of body weight repeatability data at different stages of ontogenesis shows that the selection of carriers of desirable alleles for the gene complex increases the accuracy of high-priced animal selection. Thus, in order to determine the genetic potential of Hereford bull calves more objectively and minimizing the ecological impact on breeding value, it is advisable to use a combined approach to selection that unites the assessment of the phenotype of young cattle and the genotyping of animals taking into account the complex of genes GH and GDF5.