The biologically active preparation under the symbolic name "Bison" was administered to pregnant cows for a period of 150 days (60 days before calving and 90 days after calving) 20 ml/head/day. As a result of the research it was found that the cows in the experimental group had no complications in calving, the first estrus manifested after 27.3 days, each cow was seeded as a result in the first estrus, spending only 2 doses of frozen semen, while in the cows from the control group, which did not receive the preparation "Bison", the first estrus manifested after 36.2 days, each cow was inoculated 1.75 times, spending on average 3.5 doses of M.S.C. for a gestation of a cow. Fertility was 2 times lower in the control group (50%) than in the experimental group (100%). Thus, the administration of the nominated preparation, cows in the last 2 months of gestation and the first 3 months after calving, in the amount of 20 ml/head/day, led to a decrease in the number of artificial inseminations for a gestation by 0.75 units, to a decrease in semen costs by 1.5 doses/cow, and to an increase in fertility by 50%.