A study was undertaken to identify urinary estrogen and progesterone metabolites in the female Indian rhinoceros (Rhinoceros unicornis). Measurements of these metabolites were then used to monitor ovarian function and establish normal levels and patterns of steroid excretion during the estrous cycle and pregnancy. Urine samples were analyzed for estrone sulfate and pregnanediol-3-glucuronide (PDG) by direct radioimmunoassays. Both hormones produced discrete profiles reflecting ovarian activity in nonconceptive cycles. The estrous cycle was observed to be 48 days (range 39-64) with a mean follicular phase of 14.8 days (range 13-19), followed by a mean luteal phase of 19 days (range 17-21). Of the single gestation monitored, PDG levels rose above luteal phase levels by the third month after breeding and remained elevated throughout gestation. The combined estrogen and progesterone metabolite profiles present a complete evaluation of ovarian steriod production in the mature female Indian rhinoceros.

Urine samples were obtained from free-ranging African elephants that were considered to be in and out of musth. Testosterone concentrations, measured by radioimmunoassay were significantly greater in males that were in or around the time of behavioural musth. This study supports a correlation between the observed behavioural characteristics of musth and urinary testosterone levels.

Urine samples were collected daily during ten nonfertile and four fertile ovarian cycles of four adult female lion-tailed macaques (Macaca silenus). Urine was analyzed for concentrations of total immunoreactive estrogen (Et), estrone conjugates, and bioactive luteinizing hormones (LH). The estrone conjugates of selected samples were separated by high-performance liquid chromatography (HPLC) to evaluate the relative proportions of estrone glucuronide (E1 G) to estrone sulfate (E1 S) contributing to the sum total of the conjugate measured in the samples. The estrone conjugate profile was found to accurately reflect the preovulatory estrogen peak in both nonfertile and fertile cycles as well as the early pregnancy increase which was found to be statistically significant on Day + 14 postovulation (P = 0.003). Estrone conjugate levels rose in the early follicular phase from 126.00 +/- 24.07 (SEM) ng/mg creatinine to a preovulatory peak of 471.90 +/- 62.95 ng/mg creatinine. Fertile cycles exhibited a postovulatory climb to a peak of 515.00 +/- 38.00 ng/mg creatinine on Day + 19, in contrast to the secondary rise observed in nonfertile cycles that peaked at 148.11 +/- 13.80 ng/mg creatinine on Day + 10. Bioactive LH evaluations confirmed ovulation and, in the fertile cycles, reflected the subsequent elevation of chorionic gonadotropin on Day + 18. The estrone conjugate profile of fertile cycles and early pregnancy compared favorably to the Et profile: both showed the same time course and increases in estrogen excretion.

A study of female black rhinoceros (Diceros bicomis) urinary steroid and steroid metabolite excretion was performed to determine if techniques useful for monitoring reproductive events in the Indian rhinoceros (Rhinoceros unicornis) could be utilized to evaluate the black rhinoceros. Urine samples from 19 zoo-held black rhinoceros were analyzed for estrogen, estrone conjugates (EC), and pregnanediol-3-glucuronide (PDG) content by direct radioimmunoassays. Estrogen analysis revealed that > 95 % of the estrogens present in female black rhinoceros urine are conjugated, with estrone and estradiol accounting for virtually all of these estrogens. There is no observable difference in the amount of estrogen present in estrus; postestrus; and early-, mid-, and late-gestation urine samples. Analysis of serial urine samples for EC failed to reveal any discernible levels or patterns which reflected reproductive status. Neither nonpregnant nor early-gestational female black rhinoceros' urine samples contained detectable amounts of PDG. Urinary PDG concentrations became measurable in midgestation (9-12 months prior to parturition) and rose steadily throughout the remainder of gestation. PDG levels declined sharply and became nondetectable 1 day postpartum. Though a wide range in PDG levels was observed among individual pregnant animals, each female consistently excreted increasing amounts of PDG through latter pregnancy.

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