Urinary steroid evaluations to monitor ovarian function in exotic ungulates: I. Pregnanediol-3-glucuronide immunoreactivity in the okapi (Okapia johnstoni)

Immunoreactive pregnanediol-3-glucuronide was assessed in daily urine samples from five female okapis. Indexed by creatinine (CR), the resultant profiles accurately reflect ovulation and pregnancy in this species. The infertile cycle was approximately 14.5 days by this method with the preovulatory levels averaging less than 1 ng/mg CR (N = 88) for approximately eight days (N = 28). Postovulatory levels averaged 24 ng/mg CR (N = 55) in one female and 12 ng/mg CR (N = 27) in another for approximately six days (N = 26). Pregnancy is confidently detected by three weeks postcoition by elevated pregnanediol levels that remain significantly higher that luteal phase levels until weeks before parturition.