The relationship between the lactation performance and exterior features of Ayrshire cows at first calving

The article considers the relationship between the lactation performance and exterior features of Ayrshire cows at first calving. To conduct the study, a sample of 163 heads was formed, which includes Ayrshire cows at first calving at the Integrated Agricultural Production Company “Plemzavod Maisky”. The novelty of the study consists in the fact that it determines the relationship between exterior measurements of cows at first calving (hip height, pelvic width, chest depth) with their lactation performance. The calculation of profit is carried out. The difference of profit from milk production received from animals of different groups on exterior features is established. The interrelation between exterior features and lactation performance is assessed on the basis of correlation dependence of selected features (r). For further research, three measurements are selected: hip height, chest depth, and pelvic width, because they have a moderate correlation with lactation performance (r = 0.32-0.43). These measurements are given in centimeters, which helps demonstrate the results obtained in the course of the research. It has been found that milk yield in the animals with the largest measurements, such as chest depth exceeding 81 cm, hip height exceeding 141 cm, pelvic width exceeding 34 cm is greater in comparison with their smaller peers during 305 and 100 days of the first lactation; fat and protein content in their milk is also higher. According to the results of the calculation of the economic efficiency of dairy production, the data of the study on the superiority of animals with the largest measurements by 4-5 thousand rubles per head are confirmed. The findings of the research can be used at dairy cattle breeding farms with the focus on the improvement of certain exterior features, which helps increase milk yield and, consequently, increase the inflow of cash from milk sales. In the future, it is necessary to conduct these studies to determine the most effective methods of selection and breeding work with dairy breeds of cattle.