Age composition and milk productivity of black-and-white breeding cows in the Vologda region

The intensification of dairy cattle breeding in Russia is accompanied by an increase in dairy productivity and, at the same time, a reduction in the productive long life of cows. In modern dairy cattle herds the average age of cows is 2.47 calving. Consequently most animals do not reach the age of full realization of the genetic potential for milk productivity due to excessive intensification. The purpose of the study is to study the age composition and productive characteristics of black-and-white breeding cows at different ages in the Vologda region to determine effective ways of further population development. The study is carried out using data from «Selex. Dairy cattle» Information System for 24757 breeding cows of the Vologda region. The method of grouping animals by age in lactation is applied. According to the results of the study it has been found that young cows of the 1st and 2nd calving predominate in the modern population. Their share in the population structure is 65.7%. The average age of dairy cows in the controlled population is 2.3 lactation. When comparing the actual age structure of the studied livestock with the recommended optimal structure of the herd, it is revealed that the proportion of animals aged 4 lactations and older in the actual structure is 25.9% less than the recom- mended one. The results of the calculation in groups of cows at different ages and average milk yield, the proportion of animals with different levels of productivity, the coefficient of milk production show that in order to increase the efficiency of dairy cattle breeding in the region, it is advisable to use cows in the population of a black-and-white breed for at least 3 lactation and up to the age of 6-7 lactation. The model calculation of milk production with the actual and optimal age structure of the studied livestock shows that the amount of milk received and the average milk yield per cow by herd (population) directly depend on its age and the duration of use.