Reproductive endocrine monitoring of elephants: An essential tool for assisting captive management

Considerable information now is available about the basic reproductive biology of elephants, especially females. However, as important as this knowledge is, it no longer is enough to simply compile it into a database. The potential exists for using endocrine monitoring techniques to solve real problems. This review summarizes our current knowledge of elephant endocrinology and […]

Reproductive endocrine responses to photoperiod and exogenous gonadotropins in the pallas’ cat (Otocolobus manul)

Abstract Fecal samples were collected for 14–26 months from three male and six female Pallas’ cats (Otocolobus manul) to examine gonadal steroidogenic activity in response to changes in photoperiod and treatment with exogenous gonadotropins. Females exhibited a seasonal anestrus from May–December, excreting consistently low concentrations of fecal estrogens (overall mean, 50.2±8.5 ng/g). During the breeding […]

Fecal androgen metabolite analysis for noninvasive monitoring of testicular steroidogenic activity in felids

Limited data are available on long-term, seasonal changes in testicular steroidogenic activity in nondomestic felids, primarily because of the difficulties associated with longitudinal blood sampling (e.g., handling, restraint, anesthesia). Therefore, a noninvasive approach for assessing testicular androgen production was developed using the domestic cat (Felis catus) as a model. Two adult males were injected i.m. […]

Stress-induced increase of testosterone: Contributions of social status and sympathetic reactivity

The vast number of studies in both human and animals confirm the inhibiting role of different stressors in the hormonal function of the testicles, decreasing the testosterone (T) level in the blood. However, there also are data suggesting that stress does not invariably inhibit the activity of the testicles. Moreover, the T level in blood […]