[Use of gravohormone to increase conception and fertility in cows]

Tested was the gravohormone preparation (produced in USSR and Bulgaria) to shorten the period from calving to impregnation and raise the conception rate and the fertility in cows. The experiments were carried out with a total of 84 cows (34 of the Bulgarian Red breed and 51 of the Bulgarian Brown breed) under productional conditions. The animals of the first group were injected on the 25th-28th day following calving, singly, i/m, using the Soviet made gravohormone at the rate of 10 IU per kg body weight. The cows of the second group were additionally injected with 1500 IU of the preparation (produced in 0ulgaria) on the 3rd and 6th day following insemination. It was found that the single application of 4000 IU of gravohormone between the 25th and the 28th day after calving shortened the time from calving up to the first insemination by 7.29 days, on an average, and the time from calving to impregnation--by 13.57 days, raising the conception rate at first insemination by 13.50%. The additional twofold injection with 1500 IU each time raised the rate of fertility in cows by 23.58% as against the controls.