Effects of synthetic LH-RH on ovulation in the cow

2. Observation of induced ovulation by endoscopy

Abstract

Ovulation inducing experiments in the cow by administration of a synthetic LH-RH analog were performed. The ovarian reactions to LH-RH were observed and photographed by endoscopy with the aid of a fiberscope.
Three cyclic cows and 2 anestrous cows with quiescent ovaries were given a single intramuscular injection of 1, 0004, 000 IU of PMS for causing multiple follicular developments. The preliminary treatments were followed by intramuscular injections with 600 μg and 300 μg or 300 μg and 200 μg at 90 minutes interval within 14 days when some follicular developments were noticed by rectal palpation (Table 1). The endoscopy revealed that 38 ovulations were induced 12 days after the LH-RH analog injection as shown in Fig. 15 and Plate: Fig. 613. From these results, the ovulation inducing effects of the LH-RH analog on the cow observed in the previous report were confirmed experimentally.