Аннотация:The study of feed additives based on natural ingredients, such as sapropel, is an important trend in animal husbandry. The aim of the study was to study the effectiveness of the use of a complex feed additive based on sapropel in feeding cattle. The scientific and economic experiment was carried out on fullaged cows in the conditions of the training and experimental farm of the Federal State Budgetary Educational Institution of Higher Education of the State Agrarian University of the Northern Trans-Urals. Conventional zootechnical and statistical research methods were used. According to the results of scientific and economic experience, it was revealed that according to morphological and biochemical studies of the blood of animals, all indicators were within the physiological norm. The use of feed additives based on sapropel had a positive effect on the milk productivity of cows. So, the milk yield for the period of the experiment was higher in the cows of the first experimental group by 11.5 %, and in the second experimental group by 7 % compared to the control. There was also a significant change in the qualitative composition of milk, so the mass fraction of fat increased in the second experimental by 0.26 %, and in the first experimental by 0.22 %, the mass fraction of protein changed slightly, on average by 0.05 % in relation to the control.
