Purpose: to study the effect of feeding lactating cows with a feed additive enriched with a biocomplex of free L-amino acids of plant origin on the indicators of functional homeostasis, productivity and quality characteristics of milk.Materials and methods. Research and production tests were carried out on the basis of the OS "Streletskaya" branch of the Federal State Budgetary Scientific Institution "Federal Research Center of Legumes and Groats". To conduct scientific and production tests, 2 groups of cows of 3-4 lactation were formed, 70 heads each. The groups were formed on the principle of analogous pairs.The cows of the experimental group, starting from the second day after calving, in the morning, once a day, received a granulated feed additive "ZEO-AMINO" (Russia) fraction 0.2-0.7 mm at the rate of 2% of the dry matter of the ration daily for the first 100 days lactation. Experimental animals were monitored daily. Clinical examination of animals was carried out with obligatory control of the general condition, thermometry, counting of respiratory movements and rumen contractions, assessment of the udder condition. The productivity of cows was determined according to the results of control milking. Morphological and biochemical blood tests were performed.Results. It was revealed that the daily use of a granular feed additive of fraction 0.2-0.7 mm, starting from the second day after calving, once a day at the rate of 2% of the dry matter of the diet during the first 100 days of lactation, contributes to an increase in the average daily milk yield of cows on average by 15.9%; by 7 months lactation, an increase in the average daily milk yield was established by an average of 18.3%. It was found that feeding the supplement to cows after calving due to better absorption of nitrogen in the diet and accumulation of proteins in the animal's body allows partially neutralizing the negative consequences of negative energy balance after calving, and contributes to a more intensive recovery of live weight loss, which is reliably confirmed by indicators of animal productivity. The results of a biochemical blood test suggest that the use of a feed supplement in obtaining milk has a positive effect on the assimilation of the diet, metabolism and assimilation processes in the body, activates a number of vital functions during the normal course of physiological processes and ensuring functional homeostasis, which ultimately determines increasing the milk production of animals. Analysis of the quality indicators of milk allows us to conclude that the mass fraction of fat when feeding the additive increased by an average of 0.12 abs. %; the mass fraction of protein increased by an average of 0.22 abs.%.Conclusion. To increase milk productivity, reduce the negative effects of negative energy balance after calving, and more intensively restore body weight loss, as well as increase the efficiency of using feed proteins and normalize metabolic processes, it is recommended that daily use of the feed granulated dietary supplement "ZEO-AMINO" fraction in the diets of dairy cows 0.2-0.7 mm at the rate of 2% of the dry matter of the diet, starting from the second day after calving, once a day during the first 100 days of lactation.
Hepatic Metabolic Profile Reveals the Adaptive Mechanisms of Ewes to Severe Undernutrition during Late Gestation