Comparison of Ham’s F10 with CO2 or Hepes buffer for storage of equine embryos at 5 C for 24 H.

This research compared two different storage methods for horse embryos, finding that the use of Ham’s F10 medium in combination with CO2 proves more effective than Hepes buffer for storing these embryos at a cooled temperature for 24 hours.

Study Design and Materials

• The study used 40 horse embryos, which were collected seven days post-ovulation.
• The embryos were divided into two groups and stored at 5 degrees Celsius for 24 hours.
• Two different storage mediums were used: 1) Ham’s F10 + 10% heat-treated fetal calf serum buffered by CO2, O2, and N2 and 2) Ham’s F10 + 10% fetal calf serum with Hepes buffer.

Criteria of Evaluation and Metrics

• The quality of the embryos and change in their diameter were tracked as indicators of the success of the storage method.
• Embryos stored in the CO2 medium had a higher quality score and a larger average increase in diameter compared with those stored in Hepes buffered medium.
• Post-storage, the embryos were surgically transferred into recipient mares, who had ovulated within a three-day window of the original donor mare.
• Success of the storage mediums was then determined by measuring pregnancy rates in the recipient mares at 14 and 35 days post-transfer.

Findings and Conclusion

• Embyos stored in the Ham’s F10 + CO2 medium had a significantly higher pregnancy success rate (70% and 55% at 14 and 35 days, respectively) compared with the embryos stored in the Ham’s F10 + Hepes medium (20% and 15% at 14 and 35 days, respectively).
• As a control, 20 embryos were kept in Dulbecco’s phosphate buffered saline + 10% FCS and transferred under an hour after collection. The success rate of these control embryos was not significantly different from those stored in the CO2 medium at 14 days, but was higher at 35 days.
• The study concluded that using the Ham’s F10 in combination with CO2 as a storage medium was superior to using Hepes buffer for short-term storage of horse embryos. Furthermore, this method produced satisfactory pregnancy rates when the embryos were stored at 5 degrees Celsius for 24 hours.