Soils in the Vladimir region are poorly represented by mobile forms of cobalt and zinc, below average they are provided with boron and manganese. Accordingly, there is a need for the administration of preparations containing trace elements to replenish deficient feed rations. The use of the preparation «Polysalts of microelements» leads to an increase in the level of copper, zinc, cobalt and manganese in the blood serum of cattle, restoring the physiological norm. The optimal dose of the preparation «Polysalts of microelements» has been selected. It is 300 mg daily for 20–30 days in infertile animals, or daily at a dose of 270–300 mg in the last third of pregnancy before the expected calving When using «Polysalt of microelements» for 30 days at a dose of 300 mg, 100% of the cows came to hunt. The period from calving to full libido averaged 30,9±2,39 days; the service period was 79,5±2,47 days, and the insemination index was 1,6±0,14.