Polymorphism of the CSN3, BLG, TNF-α-824, Pit-1, SCD1 genes and their influence on milk productivity of cows of the Black-and-White breed

The polymorphism of the genes CSN3 , BLG , TNF- α -824 , SCD1 , Pit-1 and the relationship of their genotypes with milk productivity of Black-and-White cows were studied. Molecular genetic studies were conducted on the Black-and-White cows ( n = 100). The genotype and allele frequency in the Black-and-White cows which is a consequence of the previous selection and breeding work was identified. A comparative assessment of the polymorphism of the studied genes with other Russian dairy breeds showed good agreement of the results. It was found that cows with the CSN3 AA genotype had a higher milk yield (by 707,3 kg) compared to the heterozygous genotype CSN3 AB ; the fat mass fraction content was higher in cows with the CSN3 BB genotype by 0,76% compared to the CSN3 AB genotype and by 0,69% with CSN3 AA . Accordingly, cows with the CSN3 BB genotype had a higher milk fat content (by 66,1 kg) than animals with the CSN3 AB genotype. Cows with the BLG В B genotype had a milk yield of 944.4 kg more and a milk fat content of 46.2 kg higher compared to animals with the BLG AA genotype. Higher milk productivity was noted in heterozygous animals TNF- α -824 GA , exceeding homozygous genotypes in milk yield by 688.7-753.8 kg, milk protein content by 20,7-27,2 kg, milk fat content by 20,6 kg. Cows with the SCD1 CC genotype exceeded animals with alternative genotypes in milk yield by 511,3 and 792,1 kg. In terms of milk fat and protein content, cows with the SCD1 CC genotype have a priority position. Cows with different Pit-1 AA genotypes had a slight advantage in protein content. The identified associative links of the CSN3 , BLG , TNF- α -824 , SCD1 , Pit-1 genotypes with milk yield and milk quality can be used in selection by selecting and matching parental pairs with desirable genotypes.