SHARE AND RELIABILITY OF THE INFLUENCE OF CAPPA-CASEIN GENE AND DIACYLGLYCEROL O-ACYLTRANSFERASE ON INDICATORS OF DAIRY PRODUCTIVITY OF COWS
The aim of the work was to study the degree and reliability of the effect of the genotypes of kappa-casein (CSN3) and diacylglycerol O-acyltransferase (DGAT1) on the indicators of milk productivity of black-and-white cattle. It was found that the CSN3 genotype had the greatest significant effect in first-calf heifers on the mass fraction of protein in milk. The share of its influence was n2 = 0,246 (F<sub>fact</sub> = 22,179; P <0,001). Also, the effect was found on the yield of milk protein n2 = 0,053 (F<sub>fact</sub> = 3,811; P <0,05). The DGAT1 genotype significantly (P <0,05-0,001) influenced all indicators of dairy cows, with the greatest influence on the mass fraction of fat - n2 = 0,154 (Fact. = 12,380). The desired allele B of the CSN3 gene has a significant effect only on the mass fraction of protein - n2 = 0,342 with a high value of Fisher's criterion - F<sub>fact</sub> = 26,489 (P <0,001), and allele K of the DGAT1 gene on the mass fraction of fat in milk - n2 = 0,163 (F<sub>fact</sub> = 17,305; P <0,001). The DGAT1 genotype has a broader influence on milk production indicators.