Milk productivity of black-and-white and Kholmogory cows with different genotypes of kappa-casein

The influence of genotypes for kappa-casein gene on the main indicators milk productivity in 1st and 3rd lactation black-and-white Kholmogory cows was studied. genotyping CSN3 carried out by method DNA diagnostics. Cows breed with genotype BB surpass group AA AB yield 166-218 fat 4.9-8.7 kg; 188-298 kg 7.7-10.2 kg, respectively. At same time difference is significant terms mass fraction protein 0.06-0.15% (Р<0.05-0.001) 0.11-0.15% (Р<0.001) (Р<0.05) 8.3-14.2 14.8-16.1 (P<0.05). have a similar advantage cattle excess 0.07-0.14% (Р<0.05-0.001), 0.08-0.11% (Р<0.05-0.001). Consequently, breeds approximately level superiority homozygous B allele over their herdmates.