Circumventing the natural, frequent oestrogen waves of the female cheetah (Acinonyx jubatus) using oral progestin (Altrenogest)

• Published in: Reproduction fertility and development Vol. 29; no. 8; p. 1486
• Main Authors: Crosier, Adrienne E, Comizzoli, Pierre, Koester, Diana C, Wildt, David E
• Format: Journal Article
• Language: English
• Published: Australia 01-08-2017
• Subjects: Acinonyx; Animals; Estradiol - blood; Female; Oocytes - drug effects; Oocytes - metabolism; Ovary - drug effects; Ovary - metabolism; Ovulation - drug effects; Ovulation Induction - methods; Ovulation Induction - veterinary; Progestins - pharmacology; Trenbolone Acetate - analogs & derivatives; Trenbolone Acetate - pharmacology
• ISSN: 1031-3613
• DOI: 10.1071/RD16007

Cheetah are induced ovulators, experiencing short, variable oestrogen waves year-round. Exogenous gonadotrophin administration induces ovulation, but success is variable and often improves if ovaries are quiescent. After affirming the presence of short-term oestrogenic waves, we examined the effect of the timing of administration of exogenous equine and human chorionic gonadotrophins (eCG-hCG) within the oestrogen concentration pattern on subsequent follicle development and oocyte and corpus luteum quality. We also investigated ovarian suppression using an oral progestin (Altrenogest, 7 days) and assessed whether Altrenogest moderated adrenal activity by reducing glucocorticoid metabolites. All cheetahs exhibited short (every ~7-10 days), sporadic, year-round increases in faecal oestradiol punctuated by unpredictable periods (4-10 weeks) of baseline oestradiol (anoestrous). Gonadotrophin (eCG-hCG) efficacy was not affected by oestradiol 'wave' pattern if administered ≥3 days after an oestrogen peak. Such cheetahs produced normative faecal progestagen patterns and higher numbers (P<0.06) of mature oocytes than females given gonadotrophins ≤2 days after an oestradiol peak. Altrenogest supplementation expanded the interval between oestradiol peaks to 12.9 days compared with 7.3 days without progestin pretreatment. Altrenogest-fed females excreted less (P<0.05) glucocorticoid metabolites than non-supplemented counterparts. Results show that Altrenogest is effective for suppressing follicular activity, may contribute to reduced glucocorticoid production and may result in more effective ovulation induction via gonadotrophin therapy.