Transcervical embryo transfer in performance mares.

The research successfully demonstrates the feasibility of establishing pregnancies in recipient mares through the transcervical transfer of embryos from performance mares. The study shows that 65.7% of the single embryos transferred resulted in successful pregnancies, which were confirmed via ultrasonographic examination 23 days after the transfer.

Research Methodology

• The mares used in this study were split into two categories, 17 as donors and 43 as recipients. The study was conducted to ensure that estrus was synchronized in all mares.
• The donor mares were artificially bred when a follicle of at least 25 millimeters was detected and this process continued until the mares ovulated.
• The ovulation day was recorded and, seven days later, uterine flushes were performed on the donor mares which constituted 111 flushes in total.
• The recovered embryos from the flushes were transcervically transferred to recipient mares within two hours.

Results and Findings

• 40.5% of uterine flushes successfully resulted in recovered embryos. This indicates that the recovery rate is nearly half of all flushes performed.
• Out of all single embryos transferred, 65.7% had successfully established pregnancy. This conclusion was reached after conducting ultrasonographic examinations 23 days post-transfer.
• However, the success rate significantly reduced to 35.3% when twin embryos were transferred, showing that the success rate decreases when more than one embryo is involved.
• The research was conducted over a period of four years. The number of flushes and embryos retrieved, as well as the resulting pregnancies, varied each year. Nonetheless, the research established a consistent success rate with single embryos.

Conclusion

• The findings of this study prove that the procedure of transcervical embryo transfer from performance mares to recipient ones can successfully lead to pregnancy.
• Single embryos have a higher rate of successful pregnancies as compared to twin embryos, which is crucial knowledge for strategizing future breeding practices.