Hastened transport of equine embryos through the oviduct of the mare.

This research study aimed to understand whether placing rabbit embryos in a mare’s uterus or infusing fluid into the uterus would speed up equine embryo transport, and if this could disrupt pregnancy. Results showed that infusing fluid can indeed hasten the transport, but it may also negatively affect future pregnancy.

Hypothesis and Test Method

• The experiment set out to test two hypotheses related to equine embryo transport within the mare’s uterus.
• The first hypothesis was that introducing rabbit embryos into the mare’s uterus would speed up the oviduct transport of equine embryos. On Day 4 of the equine menstrual cycle, some mares were given rabbit embryos, while others were not. The idea was to see whether the presence of rabbit embryos would affect the transport and recovery of equine embryos on Day 5.
• The second part of the experiment investigated if the introduction of fluid into the mare’s uterus on Day 4 and/or Day 5 would disrupt the mare’s subsequent pregnancy. This was measured in terms of the pregnancy rate on Day 14.

Results and Findings

• Contrary to the first hypothesis, the study found no significant increase in the recovery of equine embryos on Day 5 in mares that had received rabbit embryos on Day 4. This suggests that rabbit embryos did not influence the speed of oviduct transport for equine embryos.
• Regarding the fluid infusion, the study showed that mares given this infusion on Day 4 had a higher recovery rate of equine embryos on Day 5 compared to those either receiving rabbit embryos or no uterine intervention. This supports the concept that fluid infusion can accelerate the transport of equine embryos.
• However, mares that had fluid infused into their uterus on either Day 4, Day 5, or both had significantly lower pregnancy rates on Day 14 compared to those mares with no uterine intervention. This suggests that while fluid infusion can speed up embryo transport, it may also harm the mare’s chance of getting pregnant after.

Conclusion

• Overall, the study determined that introducing fluid into the mare’s uterus can hasten the transport of equine embryos, but does not appear beneficial as it may interfere with future pregnancies.
• The introduction of rabbit embryos, on the other hand, does not influence the oviduct transport of equine embryos and therefore seems irrelevant to the process.