Feeding effect on blood biochemical status and milk quality in APC "Tavolzhan" in the Tyumen region

The greatest difficulty in organizing full-fledged feeding of Holstein cows is the lactation phase immediately after calving, when milk productivity and the need for nutrients and energy increase simultaneously. Research was carried out in the agricultural production cooperative Tavolzhan, which is effectively engaged in dairy cattle breeding. The cooperative occupies a leading position in the dairy business; milk production is 7878 kg with a fat mass fraction of 4.1 %. The purpose of research is to study the feeding and quality of feed, the physiological state of animals and the quality of products obtained from highly productive cows. The relationship was determined between the diet of feeding, blood biochemical parameters and the composition of milk. In the first phase of lactation, cows have the greatest need for crude protein; therefore, a lot of protein components were included in the diet - alfalfa hay, rapeseed cake, soybean cake. In the presented diet, there is an overfeeding of crude protein, which amounted to 240 g against the need. The same ration does not provide 30 MJ of cows for metabolic energy. The consequences of using such a diet can be traced to the chemical composition of milk. Almost all indicators were normal, but an increased level of milk urea (33 mg/100 ml) indicates insufficient digestibility of feed, namely protein nitrogen. In the study of blood, an increased activity of the AST enzyme was established (the indicator approaches the upper limit of 98.67 u/l), which indicates a certain danger in damage to hepatocytes. The level of total protein and albumin is within the normal range, and the proportion of urea is increased - 7.44 mmol/l, while the norm is 2.8-8.8 mmol/l. A high level of urea indicates an increased degree of absorption of feed nitrogen. Therefore, to provide animals with a balanced diet, it is necessary to control the completeness of feeding in terms of the mass fraction of protein and urea in milk and blood, then - the necessary adjustment.