Determination of steroid hormones in wild bighorn sheep feces cimarrón (Ovis canadensis Shaw) in Baja California Mexico.

Escobar-Flores, Jonathan G.; Salame-Méndez, Arturo; Sandoval, Sarahi; Martínez-Gallardo, Roberto†

Objective: Determine steroid hormones in wild bighorn sheep feces cimarrón (Ovis canadensis) using a non-invasive method. Design/methodology/approach: Progestogens, androgens and estradiol were measured in the feces of wild bighorn sheep living in the Sierra San Felipe mountains in Baja California in the winter, spring and summer of 2007. The steroids were quantified by immunoassay, carried out in a microtiter plate. Results: The hormonal profile showed that 96 samples were feces from males and 65 from females. The concentration of progestogens in feces of females varied by season, with the highest concentrations in spring (280 ng/g). The concentrations of progestogens and estrogens in females increased as environmental conditions improved from winter to spring, coinciding with the increase in androgens in males, which averaged 23.78 ng/g. Limitations/implications of the study: With this method it was not possible to identify the sex of samples from juvenile individuals. It is recommended that fresh stool samples be analyzed in order to relate hormone concentrations to seasonal reproductive events. Findings/conclusions: The springtime increase in progestogen and estrogen concentrations in the feces of females and of androgens in males suggests the initiation of reproductive activity. The concentrations of these hormones in both sexes during the summer are very low (5 ng/g), which suggests low reproductive activity.

BAJA California (Mexico : State); MEXICO; BIGHORN sheep; STEROID hormones; FECES; PROGESTATIONAL hormones; MICROPLATES; SEX hormones

Agro Productividad, 2019, Vol 12, Issue 6, p43

2448-7546

Academic Journal

10.32854/agrop.v0i0.1380