Synchronization of estrus in the mare following intramuscular injection of prostaglandin F2α
1976 Volume 21 Issue 4 Pages 154-159
Details
1976 Volume 21 Issue 4 Pages 154-159
Synchronization of the estrous cycle with prostaglandin F2α in mares was examined between March and May 1974 on Breton and Percheron mares except one Anglo-arab in the National Tokachi Livestock Breeding Farm, Hokkaido. All mares were given 4 or 5mg of prostaglandin F2α intramus-cularly, on day 3 to 11 after previous ovulation.
Results obtained were summarized as follows:
1. Fourteen out of 17 mares (82.3%) came into estrus on day 2 to 5 and ovulation were confirm-ed by rectal palpations on day 10 following treatment in the 14 mares.
2. Serum progesterone concentrations of 5 mares determined by radioimmunoassay, decreased abruptly on the first day of treatment in 4 mares, declining below 1.0 ng/ml on day 3 after treatment and estrus were observed at this time.
In the 14 mares showed estrus with prostaglandin F2α injection, side effects such as profuse sweating, rises in vermicural intestinal movements and slight colitis were observed temporarily, whereas no side effects were observed in 3 mares failed to induce estrus.
