Effects of melatonin and progesterone administered to ewes in spring and summer.

@article{Wheaton1990EffectsOM,
  title={Effects of melatonin and progesterone administered to ewes in spring and summer.},
  author={Jonathan E Wheaton and Herbert A. Pohl and H F Windels},
  journal={Journal of animal science},
  year={1990},
  volume={68 4},
  pages={
          923-30
        }
}
Melatonin (MEL) was evaluated for effects on LH, prolactin (PRL) and fertility in spring (Exp. 1, 2) and summer (Exp. 3 to 5). In Exp. 1, 17 ovariectomized ewes bearing estradiol implants were fed 3 mg MEL or vehicle for 44 d beginning May 1. Melatonin decreased (P less than .001) PRL levels but had no effect on LH secretion and response to GnRH. In Exp. 2, 12 ewes each received a 40-d MEL ear implant or a sham implant on March 31. Progesterone-releasing pessaries (CIDR) were applied for 12 d… CONTINUE READING