Relevance. The importance of dairy cattle breeding is determined by the main results — the production of milk and dairy products. Therefore, an urgent area of research is to improve the conditions of maintenance and feeding in the cultivation of dairy cows.Methods. The research was conducted in 2023–2024 in one of the peasant farms (KFH) of the dairy sector of the Novgorod region. For the experiment, groups of cows-analogues of the black-and-white breed were formed. In addition to the main diet, the experimental group was fed G-500 feed concentrate consisting of a complex of Lactobacillus, Bacillus subtilis, Lactobacillus plantarum, Bacillus licheniformis bacteria at a concentration of 1 × 1010 CFU/g and a mineral feed additive Na6(FlO2)6(SiO2)30x24H2O produced by JSC NPF “Nov”. 14 days after the end of feeding, control milking and blood tests were performed to detectthe aftereffect of the drugs. Before and during the experiment, the litter and the barn premises were also treated with powder and a solution of thermophilic bacteria “Multi-25”. The resulting milk was analyzed for compliance with GOST 31499-2013 Raw cow’s milk. Statistical data processing was performed in the Microsoft Office Excel program.Results. As a result of the conducted scientific and economic experience to improve the conditions of maintenance and feeding, the experimental group exceeded the control group by 2.65 liters in average daily milk yield; the fat and protein content in the milk of experimental cows were higher, respectively, by 0.8% and 5.97% compared with the control. The shelf life of milk has increased.The metabolic processes of the cows improved: the blood of the experimental animals had 5.4% higher total protein content, 17.4% higher creatinine, and aspartate aminotransferase — 16% higher compared to the animals of the control group. The higher level of immune protection of the cows of the experimental group confirms the excess of the “albumin — globulin” ratio (by 6.8%) in them.