Induction of multiple follicular development and ovulation in Cross-Bred Ewes using Flugestone acetate and Follicle stimulating hormone (FSH)

Abstract

The objectives of this study were to induce multiple follicular growths and determine timing of ovulation in ewes treated with flugestone acetate and FSH. Cross-bred non pregnant ewes (n=8; 10 months of age) were intravaginaly inserted with flugestone acetate for 14 days and were intramuacularly injected with FSH twice daily for 3 days, starting on day 12 after flugestone acetate insertion. Ewes underwent laparotomy at 48 and 72 h after flugestone acetate removal (day 0) to count corpora hemorrhagica (CH) and at 192 h to count corpora lutea (CL). Blood samples were taken to determine plasma progesterone (P4) concentrations on day 0, 2, 3 and 8. Ovulation rates (numbers of CH expressed as a percentage of the total number of CL) increased (P < 0.01) from 37.0 % at 48 h, to 56.5 % at 72 h. Plasma P4 concentrations were high on day 0, and remained high on day 2, but increased (P < 0.05) on day 3 and greatest to 4.09 ng/ml on day 8, after formation of the mature CL. These results indicate that synchronization with flugestone acetate and FSH can be an effective protocol in ewes to induce multiple follicular development and ovulation in order to achieve successful embryo transfer programs or the development of reproductive technologies in farm animal species.