A deterministic simulation model for the evaluation of reproductive performance in Thoroughbred mares

Area of Science:

• Veterinary Science
• Animal Reproduction
• Equine Breeding

Background:

• Evaluating Thoroughbred mare reproductive efficiency is crucial for breeding programs.
• Deterministic simulation models offer a method to analyze complex reproductive dynamics.

Purpose of the Study:

• Develop a deterministic simulation model for Thoroughbred mare reproductive performance.
• Estimate herd-level asymptotic foaling percentage (AFP).
• Investigate the impact of early pregnancy loss and fetal loss.

Main Methods:

• Developed a deterministic simulation model for mare reproduction.
• Estimated steady-state distribution using a convergent method.
• Analyzed sensitivity of AFP to conception rate (CR), early pregnancy loss rate (EPLR), fetal loss rate (FLR), and postpartum mating interval (PMI).

Main Results:

• AFP was highly sensitive to EPLR, FLR, and CR.
• Mating during the first postpartum estrus cycle (foal heat) resulted in a higher AFP compared to mating during the subsequent cycle.
• Shortening the estrus cycle with PGF2α administration improved AFP, even without foal heat mating.

Conclusions:

• The simulation model provides valuable insights into Thoroughbred mare reproductive performance.
• Foal heat mating strategies can enhance herd-level foaling percentages.
• Interventions to optimize estrus cycles can significantly improve reproductive outcomes.