Estradiol and progesterone metabolite concentration in white-tailed deer (Odocoileus virginianus) feces

Assays of reproductive hormone metabolites require validation in each anima l species. For validation of methodology in white-tailed deer (Odocoileus v irginianus), fecal samples were collected from females that had been inject ed by blowgun with estradiol, progesterone, or a control substance. Analysi s by radioimmunoassay revealed that estradiol and pregnanediol were more ab undant fecal metabolites of estrogens and progestins than were estrone or p rogesterone. Peak excretion rates of estradiol and pregnanediol occurred wi thin 12 and 24 hr of injection, respectively. Ovulation time was estimated by measuring the frequency of occurrence of eight behavior patterns, includ ing copulation. Profiles were compiled for three deer over the course of es trus and early pregnancy for estradiol, estrone, progesterone, and pregnane diol using radioimmunoassay. Pregnanediol was excreted at concentrations ab out 1,000 times higher than those of the other three fecal steroid metaboli tes, anal pregnanediol differed in concentration during estrus, the luteal phase, and early pregnancy. Consequently, a simpler enzyme immunoassay was adapted and used to measure pregnanediol levels over the course of estrus a nd early pregnancy for seven deer. Measurement of fecal pregnanediol is use ful for monitoring reproductive events in female white-tailed deer.