Longitudinal fecal hormone analysis for monitoring reproductive activity in the female polar bear (Ursus maritimus).
Theriogenology
; 78(9): 1977-86, 2012 Dec.
Article
en En
| MEDLINE
| ID: mdl-23040062
ABSTRACT
The objective was to identify suitable enzyme immunoassays to monitor gonadal and placental function in the female polar bear. Immunoreactive progesterone, progesterone metabolite (PdG), estrogen, and androgen metabolite (T) concentrations were measured in fecal samples collected over 24 mo from captive female bears (N = 20). Whereas fecal extracts produced displacement curves parallel to the standard curve for each respective steroid, T and PdG more accurately reflected reproductive events. Concentrations of fecal T increased (P < 0.05) during the breeding season, and brief spikes were associated with estrus and mating. A postovulatory increase in PdG was not always detected, but sustained baseline T after mating appeared consistent with ovulation. Parturient bears excreted higher PdG concentrations (P < 0.05) during expected time of embryo implantation in Fall, and a late gestational rise in fecal T occurred 30 days prepartum. Many nonparturient bears also had a PdG rise in the Fall, suggesting they experienced either pregnancy loss or a pseudopregnancy. Differentiating pregnant and pseudopregnant states was not achieved using fecal PdG alone, but when combined with fecal T, comprehensive diagnoses could be made. Nonparturient bears demonstrated elevated (P < 0.05) fecal T during summer months, whereas parturient bears did not. In summary, noninvasive hormone monitoring techniques were established for the female polar bear. Although this study was directed at facilitating management and breeding efforts of captive polar bears, the methods could be applied to studies of reproductive function in wild populations.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Progesterona
/
Testosterona
/
Ursidae
/
Técnicas para Inmunoenzimas
/
Estrógenos
/
Heces
Tipo de estudio:
Prognostic_studies
/
Risk_factors_studies
Límite:
Animals
/
Pregnancy
Idioma:
En
Revista:
Theriogenology
Año:
2012
Tipo del documento:
Article
País de afiliación:
Estados Unidos