Progesterone Device Use Improves Ovum Pick-Up Efficiency in Acyclic Donors

Area of Science:

• Reproductive biology
• Veterinary science
• Animal reproduction

Background:

• Seasonal anestrus affects equine reproductive cycles.
• Ovum pick-up (OPU) is a key technique in equine assisted reproduction.
• Progesterone's role in follicular dynamics during anestrus requires further investigation.

Purpose of the Study:

• To assess follicular dynamics and OPU efficacy in mares.
• To compare outcomes with and without intravaginal progesterone (P4) devices.
• To evaluate P4 effects during acyclic (anestrus) and cyclic (breeding) seasons.

Main Methods:

• Six mares (5 years old) underwent OPU every 14 days.
• Procedures were conducted with and without P4 devices during acyclic and cyclic phases.
• Follicular dynamics were monitored via ultrasound; oocyte recovery rates were recorded.

Main Results:

• Higher follicle numbers were observed during anestrus, irrespective of treatment.
• The P4 group showed smaller follicle diameters from the 2nd to 5th post-OPU evaluation.
• Oocyte recovery percentage was higher in the acyclic phase for mares treated with P4.

Conclusions:

• Intravaginal P4 devices reduce follicle diameter during anestrus.
• P4 treatment enhances OPU efficacy in mares during the acyclic phase.
• Progesterone supplementation may improve assisted reproductive outcomes in anestrus mares.