Ovarian activity in the mare between latitude 15 degrees and 22 degrees N.

The research focused on exploring the ovarian activity in mares living between latitudes 15 and 22 degrees N. This was done by studying the presence of different size follicles and other ovarian structures over a year, using post-mortem specimens, and found a seasonal reproductive pattern in the mares.

Methodology and Findings

• The study examined the ovarian activity, identified by the presence of follicles of various sizes and both corpora haemorrhagica and corpora lutea, in a total of 3584 ovaries. The data was collected over a span of one year from post-mortem specimens.
• Significant correlations were found between the occurrence of ovulated follicles (ovulations), large and medium follicles, and the average number of small follicles per mare with the season.
• The yearly averages of ovulated, large and medium follicles were reported to be 30.1%, 13.9% and 73.9%, respectively. In addition, the average number of small follicles per mare was recorded to be 2.0.

Ovary Inactivity and Multiple Ovulations

• The study reported that on average, 21.2% of the ovaries remained inactive throughout the year.
• The research revealed that the percentage incidence of multiple ovulations was 11.9% during the study period.

Seasonal Fluctuations

• The research found that the adjusted sinusoidal curves remained above the yearly average during certain months depending on the ovaries structure. For instance, ovulations were seen from April to October, large follicles from March to September, medium follicles from February to September and small follicles from January to July.
• Similarly, the inactivity in ovaries was below the annual average from March to September.

Ovarian Activity in Right and Left Ovaries

• The study didn’t find any significant differences in activity between the right and left ovaries, suggesting similar reproductive behavior in both.

Conclusion

• The research concluded that there exists a seasonal reproductive pattern for mares living near the equator in the northern tropical zone. This information can be highlighted to better understand the reproductive habits of mares and plan breeding accordingly.