Effect of the Interval From Prostaglandin F2alpha Treatment to Ovulation on Reproductive Efficiency Rates in a Commercial Equine Embryo Transfer Program.
Authors: Pietrani Melina, Losinno Luis, Cuervo Arango Juan
Journal: Journal of equine veterinary science
Summary
Optimising the interval between prostaglandin F2α administration and ovulation (ITO) represents a practical lever for improving embryo recovery in commercial transfer programmes, as demonstrated by this Argentine analysis of over 2,200 cycles from 180 Polo mares. Researchers tracked embryo recovery rates, embryo yields per flush, multiple ovulation incidence, and recipient pregnancy outcomes across different ITOs, with mares inseminated using fresh semen and embryos recovered 7–8 days post-ovulation. Embryo recovery rates showed marked improvement with longer ITOs—increasing from just 30.7% when ovulation occurred within 4 days of prostaglandin treatment to 78.3% at 10 days—whilst multiple ovulation rates and embryo numbers per flush similarly increased across the interval spectrum. Interestingly, recipient pregnancy rates remained robust (74.6–81.4%) regardless of the donor mare's ITO, suggesting that embryo quality isn't substantially compromised by delayed ovulation. For practitioners managing donor mares, these findings suggest that allowing sufficient time between prostaglandin administration and breeding may significantly enhance recovery prospects without sacrificing recipient outcomes, though the mechanisms driving improved embryo availability warrant further investigation.
Read the full abstract on PubMed
Practical Takeaways
- •Allow at least 10 days between prostaglandin F2α treatment and ovulation in donor mares to maximize embryo recovery rates from 30.7% to 78.3%
- •Shorter intervals (<4 days) between prostaglandin treatment and ovulation significantly compromise embryo recovery in commercial embryo transfer programs
- •Recipient mare pregnancy rates are unaffected by donor mare ITO, so optimizing ITO improves overall program efficiency without compromising outcomes in recipients
Key Findings
- •Embryo recovery rate increased significantly with interval from prostaglandin F2α treatment to ovulation (ITO), ranging from 30.7% at <4 days to 78.3% at 10 days (P=0.01)
- •Number of embryos per flushing and multiple ovulation rate increased gradually with longer ITO (P<0.05)
- •Pregnancy rate in recipient mares was not significantly affected by donor mare ITO, with rates of 74.6%, 81.4%, and 77.3% for intervals <6, 6-10, and >10 days respectively
- •Optimal ITO of 10 days resulted in substantially higher embryo recovery compared to shorter intervals (<4 days)