Induction of ovulation and multiple ovulations in seasonally anovulatory and ovulatory mares with an equine pituitary extract.

This study examines the effects of equine pituitary ethanol extract (EE) on inducing ovulation in mares. The findings suggest that EE can effectively stimulate ovulation in seasonally anovulatory mares and can even stimulate multiple ovulations in seasonally ovulatory mares.

Objectives of the Study

• The research primarily aimed to understand the potential effects of a crude equine pituitary ethanol extract (EE) in inducing ovulation in pony mares that are seasonally anovulatory, with ages ranging between 3 to 15 years old.
• A secondary objective was to ascertain whether EE treatment can induce multiple ovulations in seasonally ovulatory mares. To validate this, the EE was used during both the mares’ diestrus and the first day of their estrus phase.

Methodology

• The study was carried out in two experiments. In the first experiment, 12 mares were daily treated with EE for a span of 14 days. Half of these EE-treated mares were treated with human chorionic gonadotropin (HCG), while the other half were injected with saline.
• In the second experiment, the research focused on determining if EE treatment could induce multiple ovulations in seasonally ovulatory mares. For this, 7 mares were treated during their diestrus phase, 7 mares were given treatment starting from the estrus onset, and 7 mares remained untreated.

Results

• The results from the first experiment confirmed that EE can induce ovulation in mares during their anovulatory season and that the ovulation timing can be enhanced with HCG treatment. Furthermore, the research found that the ova from induced ovulations are capable of fertilization.
• In the second experiment, results displayed that EE treatment can stimulate follicular activity and induce multiple ovulations during ovulation season in mares.

Conclusion

• The success of this research demonstrates the potential applicability of using equine pituitary ethanol extract (EE) as an effective solution to stimulate ovulation in mares who experience anovulatory seasons.
• In addition, administering EE during the ovulation period can potentially lead to multiple ovulations, which could benefit the equine reproduction industry.