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Longevity, productive and reproductive traits of cows of Black-and-White breed

The intensification of dairy cattle breeding and the crossbreeding of many breeds of cattle with Holstein breed has led to the premature culling of cows from the herd and currently in Russia the longevity of dairy cows does not exceed 2,6–3,6 calving, i. e. the animals do not live up to the period of maximum milk productivity and payback for the cost of rearing heifers. When studying the issue of productive longevity of dairy cows, the study of its association with the level of milk productivity and reproductive traits is of particular interest. Dairy productivity and reproductive function in cows are interrelated and are the main factors determining the profi tability of the dairy cattle industry. The purpose of the research was to analyze the longevity, productive and reproductive traits of cows of Black-and-White breed in the Vologda region. It was found as a result of the research that the longest duration of economic use (3,39 lactations and 1569 days) and the lifetime productivity of milk the basic fat content (27 104 kg) had animals with a blood content of Holstein breed of 26 to 49 %. Along with this, the largest number of calves (4,13 heads) was obtained from animals with this genotype during the period of economic use. Analysis of the infl uence of lifetime productivity of dams on the productive longevity and reproductive traits of their daughters showed that a longer period of economic use (985 days), the largest number of completed lactation (2,32) and higher lifetime productivity (21 574 kg) was noted in daughters of cows with a lifetime milk yield of 35 000–44 999 kg. Animals that optimally combine the parameters of productive, reproductive traits and longevity have been identified, and the economic efficiency of their use has been determined in the paper.