[Postcoital uterine microbe colonization and endometritis in the mare].

This research aimed to investigate the impact of postcoital bacterial contamination and the resulting inflammatory response on the uterus of mares after natural breeding. The study found that mares who had bacterial and/or cellular changes post-breeding exhibited better foaling rates compared to others.

Methodology

• The researchers collected Utterine swabs for bacteriological and cytological examination from 80 mares.
• Each mare was sampled once between 4 and 69 hours postbreeding. For those that did not conceive, sampling was repeated at the following estrus.
• The results obtained were compared with those procured before breeding and then correlated with the breeding outcome.

Findings

• Bacteria were cultured from 72.5% of the swabs taken after coitus.
• The spectrum of organisms included species known to potentially cause endometritis – inflammation of the inner lining of the uterus.
• Neutrophilic granulocytes (a type of white blood cell) were found in 48.8% of the cases with varying concentration levels.
• In 16.3% of mares, both bacteriological and cytological examinations showed no changes after coitus.

Conclusion

• Interestingly, mares with bacteriological and/or cytological changes at the postcoital examination had better foaling rates compared to the other mares (p less than 0.05).
• The study couldn’t find any correlation between the postcoital findings and those of the prebreeding examination. It also didn’t find any link between the interval between breeding and sampling, or the different stallions used.

This critical piece of research has concluded that normal bacterial contamination post breeding, which could potentially cause inflammation, doesn’t necessarily lead to a negative breeding outcome for mares. In fact, in this study, it seemed to improve foaling rates.