Comparative endocrinology of cycling and non-cycling Asian (Elephas maximus) and African (Loxodonta africana) elephants

Up to 14% of Asian and 29% of African elephants in captivity are not cycling normally or exhibit irregular cycles based on progestin profiles. To determine if ovarian acyclicity is related to other disruptions in endocrine activity, serum pituitary, thyroid, adrenal, and ovarian hormones in weekly samples collected for 6–25 months were compared between normal […]

Use of salivary steroid analyses to assess ovarian cycles in an Indian rhinoceros at the National Zoological Park

Abstract 10.1002/zoo.20028.abs Saliva samples were collected from a female Indian rhinoceros (Rhinoceros unicornis) housed at the National Zoological Park, and ether-extracted for analyses of androgen, estrogen, and progestin metabolites to assess ovarian cycles. Analyses of both salivary androgens and estrogens were found to reliably monitor follicular activity. Although the temporal patterns of the two steroids […]

Estrogen and LH dynamics during the follicular phase of the estrous cycle in the Asian elephant

Abstract 10.1002/zoo.10098.abs Pituitary and corpus luteum hormone patterns throughout the elephant estrous cycle have been well characterized. By contrast, analysis of follicular maturation by measurement of circulating estrogens has been uninformative. This study tested the ability of a urinary estradiol-3-glucuronide radioimmunoassay to noninvasively assess follicular development during the nonluteal phase of the elephant estrous cycle, […]

Endocrine monitoring and its application to the management of the giant panda

Abstract 10.1002/zoo.10108.abs Urinary estrogens (n=10) and progestins (n=4) were monitored in a total of 10 giant panda females. Estrogens were evaluated with two different immunoassays during the estrous period. The two different methodologies gave similar hormonal profiles, but different quantitative results due to differences in the crossreactivity of the different assay systems. High-pressure liquid chromatography […]

Hormonal and behavioral correlates of estrus in captive giant pandas

Abstract 10.1002/zoo.10047.abs Variability in female estrus expression has been identified as a barrier to captive panda reproduction [Lindburg and Millard, 1995]. In China, researchers have reported that 80% of female giant pandas in captivity exhibit “weak estrus,” or “the absence of overt estrous behavior” [Shuling et al., 1997]. Previous research on the reproductive endocrinology and […]

Characterization of reproductive cycles and adrenal activity in the black-footed ferret (Mustela nigripes) by fecal hormone analysis

Abstract 10.1002/zoo.10001.abs The reproductive cycle of the black-footed ferret (Mustela nigripes) was characterized by enzyme immunoassay (EIA) analysis of ovarian fecal steroids (estradiol, progestins) in 29 females over two consecutive breeding seasons. Estrous status was determined by measuring the vulva size and examining the percentage of superficial cells in vaginal lavages. Mean fecal estradiol concentrations […]