The effect of holstein bulls’kappa-casein gene genotype on the productive longevity of their female offspring in the republic of Bashkortostan

Increased productivity in the industry can be achieved by breeding for productive longevity through searching and using genetic markers. The study analysed data of 1476 animals with at least one completed lactation. Depending on linear affiliation kappa-casein gene genotype servicing bulls, their female offspring were divided into 4 groups. CSN3 A allele frequency studied bulls was 81.91%, B 18.09%. highest desired bulls-producers Reflection Sovering line 20.83%, which is 3.69% more than Vis Back Ideal line. animal life length analysis showed that progeny from (2.46 lactation), especially those AB (2.59 had longest life. CSN3AB lifetime milk yield (18490 kg). cows average 1st day a cow’s 9.05 kg.