Genetic potential of red-white bulls of Holstein breed

Possible and real contribution of using purebred bulls-producers of the red-and-white Holstein breed for the reproduction of the herd in order to increase genetic potential of the productivity of domestic red steppe breed APC "Lenintsy" of Maisky district of Kabardino-Balkarian republic was studied The material for the research was the data on 287 daughters of 8 bulls, in dynamics over the period of their use in the context of each lactation, individually for the daughters of each bull. The data on milk yield for the first 305 days and for the entire lactation, fat content, the duration of lactation, service and intermediate periods, calf yield and distribution by sex, number of twins, abortions and stillbirths, loss of offspring, including due to duration service period and losses based on the market value of calves at two weeks of age were considered. According to the assessment results, the highest breeding value is represented by the highest breeding value offspring of the bull Grilyazh 6977, whose daughters, from the 3rd to the 7th inclusive, consistently gave more than 6000 kg of milk in the first 305 days of lactation. In the same feeding and keeping conditions, only the daughters of the bull Twist 72849 on the 4th and 5th, and the bull Gear 1883 on the 4th, surpassed the limit of 6000 kg. During the analyzed period, more than 250 calves were not received from the broodstock for various reasons. Under the conditions of a particular farm, in terms of total indicators, the use of bulls-producers of the red-and-white Holstein breed, with the exception of the bull-producer Grilyazh 6977, did not have a noticeable improving effect.