Association of κ-casein, β-lactoglobulin, α-lactalbumin and leptin gene polymorphisms with bovine productivity traits in Western Siberia

The Simmental breed (n=182) and Siberian breed (n=131) cows were genotyped using the CSN3, BLG, LALBA, and LEP genes. In both populations, the frequency of homozygotes did not exceed 10 %, and the proportion of heterozygotes was at the level of 40-45%. The actual genotype distribution corresponded to the theoretically expected Hardy-Weinberg distribution. In terms of milk yield, cows of the «Sibiryachka» breed with the BLGAA genotype significantly outperformed cows with the BLGBB genotype (p<0.05), and in the Simmental breed, cows with the BLGAA genotype had a higher milk yield than BLGAB (p<0.01). According to the LALBA gene in the Simmental breed, cows with the LALBABB genotype were superior to cows with LALBAAA in fat content (p<0.05), in the «Sibiryachka» breed, higher fat content was observed in cows with the LALBAAB genotype (p<0.05). In both breeds, cows with the LEPCC genotype outperformed cows with the LEPTT genotype in fat content (p<0.05). According to the reproduction indicators, cows with the LALBAAA and LEPCT genotypes had an earlier age of insemination in comparison with cows with the LALBABB and LEPCC genotypes (p<0.05). Cows with the LEPCT genotype had a longer calving interval than cows with the LEPCC genotype (p