Evaluation of simplified Folltropin-V^® (FSH) protocol on follicular turnover in Yankasa ewes

Abstract

The study was conducted to evaluate the effects of simplifying pFSH (Folltropin-V^®) protocol on ovarian follicular turnover in Yankasa ewes. Fifteen Ewes were synchronized for estrus with double injections of 10 mg Dinoprost tromethamine (Lutalyse^®) on day 0 and day 10 and randomly allocated to 3 groups. {Cn; control (n= 5, No FSH treatment), F1 (n=5 received FSH once daily) and F2 (n=5, received FSH twice daily at 12 hr. interval)}. Folltropin-V^® treatments commenced on Day 8 (equivalent to 80 mg, in decreasing doses over 3 days). Blood samples were collected an hour before and after 1st injection of FSH, then every 12 h over the course of treatment, and then every day till end of estrus. Serum was extracted and assayed for estradiol-17β. Ultrasonic scanning of the ovaries was conducted on day 11. Follicles were counted, measured and classified. Onset of estrus was earlier in F₂ than F₁ being 16.8 ± 5.0 h and 27.6 ± 4.0 h, respectively. Duration of estrus was shortest for F₁ (39.2 ± 11.8 h) and F₂ (47.6 ±10.6 h). Estradiol-17β concentrations were elevated in the F₁ than F₂ 1 h after 1st FSH administration, but it was not significant (P > 0.05). Estradiol-17β in F₂ (2.7 ± 0.52 pg/ml) was higher than F₁ (1.64 ± 0.48 pg/ml) and this was not significant (P > 0.05). A significantly higher number (P < 0.05) of small follicles < 2 mm were observed in F₂ (3.6 ± 3.4) than F₁ (0.6 ± 0.9). Medium sized follicles 3 mm - 4.5 mm was higher (P > 0.05) in F₂ (2.4 ± 2.6) than F₁ (0.6 ± 0.9). Number of large follicles >4.5 mm were similar (P > 0.05) being 2.4 ± 2.3 and 1.4 ± 1.2 in F₂ and F₁ respectively. Both single and double daily FSH protocols were equally efficient in inducing multiple follicular developments.

Keywords: Estradiol-17β, Simplified FSH protocol, Superovulation, Ultrasonography, Yankasa ewes