Postpartum ovarian activity and serum estradiol-17beta level in Thai crossbred native mares.

The research is about the postpartum ovarian activities in Thai crossbred native mares, specifically the timing of the first postpartum estrus and ovulation, as well as changes in estradiol-17beta (E2) levels. The results could help improve breeding management and foal production.

Methods

• Twenty-five Thai crossbred native mares were chosen and observed following parturition or childbirth.
• Methods used for observation include estrous detection, transrectal palpation, and reproductive ultrasonography. These techniques were designed to study the mares’ postbirth reproductive activities.
• Blood samples were also drawn from the mares for analysis of E2, a form of estrogens often associated with reproductive health in female mammals.

Findings

• Out of the 25 mares, 23 (or 92%) had their first ovulation within 20 days after giving birth.
• The mean time from birth to the first estrus and ovulation were 10.3 and 13.4 days respectively, both with acceptable standard deviations (a measure of variability).
• The mares’ serum E2 levels increased from an average of 7.0 to a peak of 10.8 pg/ml, roughly 2 days before ovulation.

Conclusion and Implications

• The study suggests that breeding management for postpartum mares should commence around day 10 after birth.
• Observance of the mares’ ovarian activities using the mentioned methods can aid in this management.
• However, the condition of the uterus should also be considered in conjunction with the ovarian activities after birth. Doing so may lead to better breeding performance and increased foal production.