Polymorphism of beta-lactoglobulin and prolactin genes in Russian meat merino sheep and its effect on dairy productivity

The article presents the results of genotyping of Russian meat merino sheep (n = 30) by productive marker genes: beta-lactoglobulin (?-LG) and prolactin (PRL). The research was performed by PCR-PDRF in the laboratory of Immunogenetics and DNA technologies of VNIIOK – branch of the North Caucasian FNAC. According to the results of the molecular genetic analysis, it was found that the polymorphism of the ?-LG and PRL genes in this sample is represented by two alleles: ?-LGA, ?-LGB and PRLA, PRLB. The absence of individuals carrying homozygous ?-LGAA and PRLAA genotypes was revealed. It was found that sheep carriers of heterozygous ?-LGАВ and PRLАВ genotypes outperformed their peers with homozygous ?-LGВB and PRLВB genotypes in milk yield, but at the same time they were inferior in fat and protein content. The variability of the dairy productivity of sheep of different genotypes in the beta-lactoglobulin and prolactin genes indicates the possibility of breeding work aimed at increasing this indicator for the above genes.