Association of Growth Hormone Gene Polymorphisms and Calpastatin Gene with Quality of Sheep Meat

In connection with the increasing interest in the production of young mutton and lamb, priority is given to the study of genes that control meat production. Alleles of genes calpastatin (CAST) and somatotropin (GH) may act as potential markers of sheep meat productivity. However, until now there is no information on the influence of these genes on the indicators of meat productivity of sheep of Russian breeds. Based on this, the purpose of this research was to study the polymorphism of the CAST and GH genes in meat and wool sheep of the 1/2 Poll Dorset x 1/2 North Caucasian meat - wool genotype bred in the Stavropol Territory (Russia) and their influence on the traits of meat productivity. Genotyping of sheep for somatotropin and calpastatin genes was carried out by polymerase chain reaction (PCR) with further study of restriction fragment length polymorphism (RFLP). Three genotypes were identified for the GH gene (AA, AB, and BB) and two for CAST (MM and MN). The highest frequency of occurrence for the GH gene was characterized by the heterozygous AB genotype (42.8%), for the CAST gene - the homozygous MM genotype (87.9%). These genotypes were correlated with quantitative and qualitative parameters of meat productivity. The best indicators of meat productivity were in the bright AB, BB, and MN genotypes of the growth hormon and calpastatin genes. The slaughter weight of individuals of the AB, BB genotype of the GH gene and the MN genotype of the CAST gene is higher by 6.3, 7.3, and 5.2%, respectively. According to the point assessment of the "marbling" of meat, animals with the indicated genotypes outnumbered their peers by 1.8; 2.1 and 3.7 points.