Meclofenamic acid extends donor-recipient asynchrony in equine embryo transfer.

This research article studies the effect of meclofenamic acid on extending the acceptable asynchrony window in an equine embryo transfer process, thereby potentially improving pregnancy rates.

Study Objective

• The main purpose of this study was to discover the influence of meclofenamic acid, a prostaglandin synthetase inhibitor, on the allochronous recipient mares. It investigates if administering this drug could widen the acceptable window of asynchrony for equine embryo transfers.

Methods & Experimentation

• The researchers used 72 Grade 1 horse embryos, which were transferred non-surgically into the uteri of recipient mares. These mares had ovulated 2, 3, 4 or 5 days prior to the donor.
• Half of the mares in each group were given 1g of oral meclofenamic acid treatment, which began on Day 9 after ovulation and continued for 7 days post the embryo transfer.

Result Analysis & Comparisons

• The results varied depending on the degree of asynchrony between donor and recipient mares.
• For an asynchrony of +2 days, both the treated and untreated group had similar pregnancy rates – 9/10 pregnancies and 8/10 pregnancies respectively.
• When asynchrony was increased to +3 days, the treated group showed significantly better results with 8/10 pregnancies compared to 2/10 in the untreated group.
• The difference was less pronounced for +4 days and +5 days asynchrony, indicating diminishing effects of the treatment with greater asynchrony.

Conclusions

• Meclofenamic acid played a role in aiding the establishment of pregnancy in recipient mares that ovulated prior to the donors, but it rather seemed to do so through a mechanism other than suppressing luteolysis as they had hypothesized. Luteolysis in most of the mares, treated or otherwise, occurred normally.
• The treated mares that ovulated three days before the donor showed a significantly higher rate of pregnancy, indicating the potential application of meclofenamic acid in improving the efficacy of equine embryo transfer procedures in certain situations.