Endometritis, salpingitis and fertilisation rates after mating mares with a history of intrauterine lumenal fluid accumulation.

This research article investigates the occurrence of uterine and oviductal inflammation, and fertilisation rates in mares after mating, especially those with a history of intrauterine lumenal fluid accumulation. The study discovered an increased incidence of endometritis in inseminated mares with or without pre-existing uterine fluid but no significant difference between these two groups. Fertilisation rates and oviductal oocyte recovery remained equivalent in groups with or without pre-existing uterine fluid. Meanwhile, mares inseminated with semen after 1% glycogen treatment showed no higher incidence of endometritis than those receiving semen alone, but had a lower fertilisation rate.

Study Design and Methodology

• The researchers carried out two experiments, primarily monitoring the post-ovulation inflammation condition and the fertilisation rates in different groups of mares.
• In the first experiment, they investigated mares that had previously exhibited intrauterine lumenal fluid during a dioestrus phase.
• The second experiment involved infusing 1% glycogen to induce acute endometritis in mares.
• Endometritis was evaluated using uterine cytology and histology. Oviductal inflammation was measured histologically as well.
• Fertilisation rates were established by calculating the percentage of cleaved ova recovered through retrograde flushing of the oviducts.

Key Findings

• Mares that were inseminated regardless of having pre-existing uterine fluid showed a higher incidence of endometritis.
• However, the prevalence of endometritis was not higher in mares with uterine fluid than in mares without uterine fluid, suggesting the pre-existence of uterine fluid does not affect subsequent endometritis rate.
• Equivalence in fertilisation rates and oviductal oocyte recovery was found in groups with or without pre-existing uterine fluid accumulation.
• Mares receiving semen plus 1% glycogen infusion didn’t exhibit an elevated endometritis incidence compared to those getting semen alone.
• The fertilisation rate was found to be lower in mares receiving semen with 1% glycogen treatment than in those receiving semen alone, suggesting the glycogen treatment negatively affects the fertilisation process.
• All inseminated groups consistently displayed a higher incidence of endometritis relative to salpingitis.

Conclusion

• This study implies that the history of intrauterine lumenal fluid or infusion of 1% glycogen does not significantly affect the chance of endometritis after insemination. Still, the role of 1% glycogen treatment in lowering fertilisation rates in mares requires further exploration.