| Abstract: | Food additives made of placenta tissues of healthy cattle, included in the diet of cows 23–38 days before calving and/or in different intervals of the postpartum period, stimulated the resumption of ovary activity and the manifestation of normal estrus cycles (with ovulation) in cows. The cow fertilization rates during 80 days after calving was 50–80%. These values increased more than twofold in comparison with the fertility level of cows fed a normal diet. The level of fertilization after inclusion of placenta‐containing additives in the diet of cows 5 days before ovulation, in estrus cycles that took place during 6 months after calving, increased 38 % on average, in comparison with that of cows fed a normal diet. |
