Relationship of GH and CAST gene polymorphisms with body weight parameters in crossbred young sheep

The application of knowledge about the heritability of a genetic resource in sheep breeding helps to preserve and improve local sheep breeds adapted to specific environmental conditions. Working with genetic data analysis methods opens up new opportunities for breeding and improving sheep breeds that meet the requirements of the modern market and ensure food safety. The work revealed a relationship between the live weight of crossbred young sheep with the heritability of complex genotypes of genes: growth hormone (GH), calpastatin (CAST). The research was carried out by PCR-RDRF in the Laboratory of Immunogenetics and DNA Technologies of North Caucasian National Research Center. As a result of the conducted studies, the presence of the following alleles was determined for the GH gene: the desired marker allele GHB and the allele GHA; for the CAST gene, the presence of the desired allele CASTN and the allele CASTM. The genotypes of the studied genes included both homozygous (for the GH - GHAA; GHBB gene, the CAST - CASTMM and CASTNN genes) and heterozygous variants (for the GH-GHAB gene, the CAST - CASTMN gene). As a result of the analysis of the selection of the studied parental pairs with certain variants of gene complexes according to the GH, CAST genes, crossbred young animals (blood type ? kalmyk fat-tailed breed ? Charolais and blood type ? kalmyk fat-tailed breed + ? dorper), carriers of gene complexes with desirable marker alleles according to the GH, CAST genes (GHABCASTNN; GHBBCASTMN; GHABCASTMN; GHBBCASTMM; GHAACASTNN; GHABCASTMM; GHAACASTMN). Each descendant had at least one desirable marker allele of the studied genes inherited from their parents in their gene complex. Genetic analysis helps in animal breeding, makes it possible to purposefully select animals. In this study, animals with gene complexes focused on meat productivity, which plays an important role in the development of meat sheep breeding.