Relationships between intrauterine infusion of N-acetylcysteine, equine endometrial pathology, neutrophil function, post-breeding therapy, and reproductive performance.

The research article explores the effect of N-acetylcysteine (NAC), an agent that reduces mucus and inflammation, on the fertility of mares suffering from a condition called endometritis. Through a series of studies, the research confirmed that NAC doesn’t harm horse uterine tissues, reduces mucus production, slows down neutrophil activity, and enhances fertility rates when accompanied with a regimented post mating treatment.

Study Methodology

In the research, three connected studies were performed:

• Study 1 evaluated biopsy samples of the uterine lining from mares treated with saline solution, as a control group, and a form of NAC.
• Study 2 observed the phagocytic (the process of cells eating bacteria) activity of neutrophils in blood serum after NAC application.
• Study 3 recorded the fertility rates of several groups of mares before and after treatment with NAC and supplementary therapies.

Research Findings

The findings from the research were promising:

• NAC did not cause any harm to the uterine lining of the mares.
• In the NAC-treated group, there was significant reduction in the thickness and staining intensity of extracellular mucus.
• Neutrophil function was found to be reduced by 3% of NAC, whereas reduction was not seen at a concentration of 0.5% .
• The first-attempt pregnancy rates after the NAC treatment were found to be 77% for mares who were repeat breeders, 74% for the reproductively normal mares, and 56% for mares who were treated for bacterial endometritis in the previous cycle.
• The pregnancy rate was 89% for the mares which were given post-coital treatment with uterine lavage and oxytocin; an increase when compared to 60% for those treated with uterine lavage and a gram of ceftiofur.

Conclusion

The researchers concluded that intrauterine infusion of N-acetylcysteine had a positive effect on the fertility rates of mares. Importantly, intrauterine treatments using a 3.3% solution of NAC were not irritating and reduced neutrophil (cells that fight bacteria) activity. The fertility of mares, especially those experiencing mucus overproduction without any uterine pathogens, significantly improved with NAC treatment. Post mating treatments such as uterine lavage and oxytocin also positively contributed to the increased rates of pregnancy.