Elements of calcium metabolism in the organism of dairy cows in winter and summer feeding rations

The article is devoted to the actual problem of studying the peculiarities of calcium metabolism in the organism of milk cows in winter and summer feeding rations. Experimental and analytical studies were carried out at the All-Russian Research Institute of Reclaimed Lands at the winter and summer rations feeding cows of the black and motley breed with a productivity of 4600-5000 kg of milk. In the experiments, the methodical principle of “unity of the intergroup difference” and the presence of control animals was provided, which enabled obtaining objective comparative experimental data and reliable conclusions based on mathematical data processing using statistical computer programs. The study of the results of physiological experiments was carried out by methods of correlation and regression analysis. Correlation analysis was used to determine the interdependence of calcium content in faeces, urine, milk and in the body (balance) of animals from its content in the diet. He made it possible to reveal the general (linear) interrelations in the metabolism of the element occurring in the animal's organism during winter and summer feeding rations. The calculation of the equations of pairwise nonlinear regression showing the dependence of the content of a specific chemical element in feces, urine, milk and animal body on its consumption in feed and water allows to reveal the true form of communication, the effect of the element content factor in the diet on the chemical composition of animal products and excrement. In the experiment on milking cows (balance experiments), the peculiarities of calcium intake with food and water were established, and that the calcium of the feed was mainly excreted from the body of the cow with faeces, and from the muscles and bones by urine.