Follicular dynamics in mares treated with an equine pituitary extract.

This research investigates the effects of an equine pituitary extract on the follicular development in mares. Increased growth and ovulation were observed in larger follicles, while smaller follicles decreased in number as larger follicles grew in response to the extract.

Follicular Dynamics and Pituitary Extract Treatment

The research focuses on studying the effects of equine pituitary extract on the follicular dynamics of 112 mares. The specific interest is in the growth and ovulation of follicles that are greater than 10mm in diameter at day 15 post-ovulation.

• This study found that the extract led to the growth and ovulation of larger follicles.
• Mares that showed a higher number of these larger follicles subsequently exhibited higher ovulation rates.

Observations on Smaller and Large Follicles

Interestingly, as the larger follicles increased, there was a corresponding decrease in the number of smaller follicles.

• The study recorded a decrease in the number of follicles less than 20mm in size.
• This shift aligns with the increase in the number of larger follicles, those with diameters at or above 20mm.

Single versus Multiple Ovulations

The research showed differences in how extract-treated mares ovulated, depending on the size difference of their largest follicles.

• Mares that had a larger size difference (in millimeters) between their largest and second largest follicle were more likely to have a single ovulation.
• In contrast, mares with a smaller size difference between these follicles had multiple ovulations.

Bilateral to Unilateral Multiple Ovulations

The ratio of bilateral to unilateral multiple ovulations didn’t significantly differ from the expected ratio, which is based on the assumption that ovulation side occurs independently.

• In observed vs expected cases, the ratio stood at 59:19 and 62:16, respectively.
• This suggests that the side of ovulation perhaps doesn’t directly influence the results.