Serum testosterone in captive male rhinoceros: Effects of season, age, stress, and sociosexual environment

All rhinoceros species are in some degree of endangerment. Understanding the reproductive physiology of rhinoceros species will help in management decisions with both free-ranging and captive populations. In mammalian species studied, testosterone plays a key role in spermatogenesis and libido. Testosterone concentrations, depending on the species, may vary according to age, season, social status, stress […]

Standardization and validation of a simple, sensitive, second antibody format enzyme immunoassay for growth hormone determination in mithun (Bos frontalis) plasma

Abstract 10.1002/zoo.20069.abs To facilitate research into the action of growth hormone (GH) in mithun (Bos frontalis), we standardized and validated a simple and highly sensitive enzyme immunoassay (EIA) for GH determination in mithun blood plasma on microtiter plates using biotin-streptavidin amplification system and the second antibody coating technique. Biotin was coupled to GH and used […]

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 […]

Annual fecal glucocorticoid metabolite concentrations in pregnant and pseudopregnant polar bears (Ursus maritimus) in North American zoos

Polar bears face a tenuous existence in the wild due to climate change and in North American zoos due to a shrinking population and low reproductive success.  A non-invasive diagnostic test that distinguishes pregnant from pseudopregnant bears is necessary to pinpoint when reproductive failure is occurring. However, fecal hormone metabolite patterns commonly used to determine […]