Effect of oxytocin and indomethacin on the estrous cycle of goats.

The effect of oxytocin and indomethacin on luteal function during the estrous cycle in goats was investigated. Daily subcutaneous administration of oxytocin given on days 12-15 of the estrous cycle had no effect on length of the cycle or concentrations of progesterone and estradiol-17 beta. Oxytocin given on days 3-6 shortened the cycle and decreased concentrations of progesterone, but increased the estradiol-17 beta to levels similar to seen at estrus. These changes caused by oxytocin were prevented by indomethacin, a prostaglandin synthetase inhibitor, although indomethacin given alone did not affect luteal function. These results suggest that luteal function affected by prostaglandin in the early luteal phase of goats may be different from that in cattle.