ASSOCIATIVE RELATIONSHIPS OF KAPPA-CASEIN, BETA-LACTOGLOBULIN, LEPTIN AND SOMATOTROPIN GENOTYPES WITH DAIRY PRODUCTIVITY IN SIMMENTAL BREED

Abstract

In order to determine the productivity of Simmental cattle population, genotyping of animals by genes associated with economically useful traits was carried out. The application of results in planning long-term selection and breeding work, considering genotypes of breeding bulls was proposed. Polymorphism of kappa-casein (κ-Cn), beta-lactoglobulin (βLG), leptin (LEP) and somatotropin (GH) genes in Simmental cattle population (The breeding facility “Krasniy Velikan”) was performed using of PCR-RFLP method. The level of productivity on milk yield, fat and protein content in milk was established. The combination of genotypes in the Simmental cattle population was determined on the basis of marking hereditary information by genes of quantitative traits to increase the productive potential of animals. In the studied population of Simmental breed polymorphisms were found to be polymorphic in all studied genes. The connection of controlled genes with indicators of animal milk productivity is established. Genotypes BB (κ-Cn), AA (βLG), BA (GH) and AB (LEP) were characterized by the highest rates of milk yield during the first lactation, genotypes AB (κ-Cn), AA (βLG), BA (GH) and AA (LEP) – the highest fat content in milk, genotypes AA (κ-Cn), BB (βLG), BA (GH) - the highest protein content in milk. The analysis of associative connections of the main productive traits of Simmental cattle with polymorphism of genes of kappa-casein, growth hormone, leptin and beta-lactoglobulin makes it possible to establish the most desirable complex genotypes: κ- to increase the fat content of milk, κ-CnAAGHBALEPAA / ABΒlgBA in selection to increase the protein content in milk. It is shown that in order to increase the productivity of Simmental cattle populations it is necessary to genotype breeding animals by genes associated with economically useful traits and apply the results when planning long-term plans for breeding work considering the genotypes of breeding bulls.