INFLUENCE OF COW FATNESS PRIOR CALVING ON THE QUALITY OF THE FIRST LACTATION YIELD COLOSTRUM

The aim of the research is improving the quality of dairy breed colostrum by regulating their fatness before the calv-ing. Research was carried out in 2018-2019 in the conditions of dairy breed complexes of SEC «Yuzhny», LLC «Zvezda», LLC «Radna» of the Samara region on cows of: Bestuzhevskaya; Black-and-White of domestic selection; Holstein, imported from Germany; Ayrshire from Finland. The chemical composition, physiological prop-erties and content of immunoglobulins were studied in colostrum of the first lactation yield, 30-60 minutes after the calving. It has been found that if the fatness decreases below 3.6-4.0 points, the fat in the colostrum of Bestu-zhevskaya breed decreases by 0.5-1.2%, Back-and-White – by 0.5-0.9%, Holstein – by 0.7-1.6%, Ayrshire – by 0.5-1.4%, the protein, respectively by 1.9-5.5; 0.7-1.5; 0.5-1.3; 1.1-4.3%. If the fatness increases above 4.0 points, fat and protein in the colostrum also decreases. Colostrum of all milk breeds studied, showed that its acidity meets the phiziological requirements, with the exception of Holstein breed with fatness below 3.0 points (44.5ºT). When the fatness decreased below the optimum, the content of immunoglobulins in the colostrum lowed too, respectively, in breeds by 8.1-24.5; 5.3-12.9; 6.1-16.6; 6.7-22.7%, with an increase of 4.2; 1.9; 7.4; 4.9%. Thus, the reduction or increase of breed fatness, compared to the optimal level (3.6-4.0 points), leads to a decrease of main components in colostrum including density, acidity, and the most important point a decrease in the content of immunoglobulins, which perform a protective function newborn calves.