EVALUATION OF ECONOMICALLY USEFUL TRAITS OF DAIRY CATTLE

Abstract

The relevance of the research is due to the increased attention to the global problem of food security and the significant role of the dairy industry in solving it through the production of milk and its products as irreplaceable and highly nutritious elements of human diets. In this regard, the search for ways to increase the production of milk and dairy products remains important and is implemented, among other things, through monitoring the economically useful traits of cattle in certain production conditions. The study of the main breeding traits of dairy cattle was carried out in the conditions of the dairy farm “Novoselytsia” of Zhytomyr region. For the purpose of milk production, they breed cattle of the Ukrainian Black-and-White dairy breed. Keeping animals in farm conditions is carried out in stalls with animal exercise on walking platforms. Animals are fed three times a day with the same diet throughout the year with free access to water throughout the day. Cows are milked into the milk pipeline three times a day. Manure is removed using a scraper-tractor system. The evaluation of economically useful traits of Ukrainian Black-and-White dairy cows was carried out in the context of three lactations. The milk productivity of cows, their reproductive capacity, age and live weight of cows at first insemination and calving, functional properties of the udder, dependence of milk productivity of cows on the shape of their udder were studied. The milk productivity of the cows in the farm in the context of three lactations ranged from 7812 kg (I lactation) to 8198 kg (III lactation), the fat content in milk ranged from 3.92% to 3.88%, the protein content in milk – from 3.22% to 3.27%, the total amount of milk fat and protein – from 559 kg (I lactation) to 586 kg (III lactation), respectively. That is, with the age of cows, there was a tendency to increase the quantitative indicators of milk production and some deterioration in the qualitative ones. It was found that the age of the first insemination in the herd was 19.4 months on average, the first calving – 28.6 months, with a live weight of 409.8 and 502.9 kg, respectively. With the age of cows, there was a deterioration in the reproductive capacity of cows, an increase in the service period, inter-calving period, and a decrease in the reproductive capacity coefficient, which, in our opinion, is associated with an increase in the milk production of cows. The difference of cows depending on age in functional properties of the udder was established – the single milk yield and the duration of milking reached the highest values in cows in the third lactation. A high intensity of milk production in cows regardless of age was recorded – 1.94–1.99 kg/min. The udder shape of the cows in this herd was distributed as follows: 85% of cows had a bathtub- and cup-shaped udder, and 15% had a rounded udder. Different levels of influence of udder shape on milk production of cows depending on their age in lactation were found.