Transcervical collection of equine conceptuses between 10 and 16 days after ovulation.

The research paper investigates a method for collecting equine conceptuses, early-stage embryos, from pregnant mares between 10-16 days after ovulation, with the use of a rigid catheter. The study also finds that this procedure has minimal impact on the mares’ subsequent fertility.

Research Methodology and Conceptus Recovery

• The research team performed 131 collections using a rigid catheter. The mares chosen were already confirmed to be pregnant through ultrasonography.
• The research spanned from Day 10.5 to Day 16.5 post-ovulation (Day 0 = ovulation day). A total of 139 conceptuses were collected, including 124 singles, six twin sets, and one triplet set.
• Out of the total conceptuses collected, 86% (or 120 embryos) remained intact after the collection process. About 10% were collapsed, and in about 4% of cases, collapsed trophoblastic membranes were surrounded by an intact capsule.

Recovery Rate and Collection Process

• The researchers noticed a variation in the recovery rate of intact conceptuses. The rate ranged from 99% for conceptuses collected between 10.5-12.5 days to 40% for conceptuses collected on Day 16.5.
• Further observations indicated that more uterine flushes per recovery were required to collect conceptuses on Day 14.5 than on Days 10.5 and 11.5. Similarly, the total volume of the flushing medium used was also significantly more on Day 14.5 than on previous days.

Impact on Subsequent Fertility of the Mares

• An essential aspect of this study was to analyze the impact of the collection process on the future fertility of the mares.
• Out of the 100 mares inseminated at their first estrus (a period of sexual receptivity) following the embryo collection, 70 became pregnant. This data suggests that the collection technique does not have a detrimental effect on subsequent fertility, making it a viable method for embryo collection in equine reproductive research or practical breeding.