Assessment of the genetic potential of cattle by marker genes
As material for study, selections of cows of black and motley, bestuzhevsky and simmentalsky breeds served. Polymorphism of genes kappa- and beta-casein, beta-lactoglobulin, alpha-lactoalbumin, prolactinum and a somatotropin is revealed by the PCR-RFLP method. CSN3 B allele of kappa-casein is associated with higher yield of milk and also higher milk protein content and a suitability to production of cheese. The genotype αLA BB alpha-lactoalbumin is associated with higher milk yield and a genotype αLA AB with higher protein content and fat in milk. Existence in a genotype of CSN2 B allele of beta-casein correlates with the higher content of fat and casein. Allele of BLG B of beta-lactoglobulin gene and allele ALA B of alpha-lactoalbumin is connected with the high content in milk of casein proteins and high percent of fat and the BLG A option is characterized by the high content of serumal proteins. The cows having GH VV genotype on a hormone of growth are characterized by higher yields of milk and also of milk fat and protein. Milk of cows with a genotype of GH LL has higher fat content of milk. Existence of allele GH D of the third intron of a gene of a hormone of growth is optimum from economic value point of view. Cows with genotypes of GH DD have the greatest milk yield and a bigger yield of milk fat in comparison with GH CC GH CD genotypes. Cows with PRL BB genotypes on prolactinum gene, according to many researchers are the best compared by high yield of milk and fat content in milk, they also show the highest yield of milk fat and protein.