The uterine microbiome- key to equine infertility?

The University of Melbourne

  • Project code: PRJ-011248

  • Project stage: Closed

  • Project start date: Tuesday, October 2, 2018

  • Project completion date: Sunday, February 28, 2021

  • Journal Articles From Project: The equine uterine microbiome and its role in fertility Frontiers in Veterinary Science (Issue: TBD on 30/11/2021), The equine penile microbiome and its role in fertility Frontiers in Veterinary Science (Issue: TBD on 30/10/2021)

  • National Priority: HOR-Thoroughbred breeding


The expected outcomes are an improved understanding of the role of the bacterial microflora of the equinereproductive tract on equine fertility. Following on from this, novel diagnostic and treatment methods for equineinfertility will be developed. As outlined above there could be commercial applications for both. In addition, we planto formulate easy-to-use on-farm protocols for management and treatment that could significantly improvefertility outcomes. These might include alterations to how stallions are treated between breedings or how mares areprepared for breeding.
Another important outcome of this study will be the formulation and dissemination of current evidence-basedguidelines for treatment and prevention of endometritis and therefore an increased pregnancy rate in the mare.
The ultimate outcome of this research will be improved fertility rates for broodmares, as the causes of infertility in some older, chronically infertile mares are identified and effective treatment regimens are developed. These older mares have often already produced successful offspring and their reproductive success is of high genetic value to the industry. This, in turn, will increase the number of high quality foals born, and have important flow-on effects for the racing industry, as more of the foals that are born are likely to reach the racetrack


Thoroughbred Horses

Research Organisation

The University of Melbourne

Objective Summary

The objectives of this project are to:
1) identify differences in microflora between fertile and infertile mares.
The results may lead to new treatment options for mare infertility. Beneficial probiotic strains may be identified in fertile mares, which could be inoculated into the reproductive tract of subfertile mares.
2) compare traditional culture dependent methods of assessing the presence of bacteria in the equine uterus with novel culture-independent techniques.
These findings will be important to assess a potential need for new diagnostic procedures. Culture-independent methods allow the identification of a higher number of microorganisms and therefore potential candidate pathogens that can be linked to infertility. Additionally, the resistance gene profile of the isolated microorganisms may be used to identify mares at risk for infertility.
3) assess the microbiome in fertile and infertile mares at several time points.
Comparison of the microbiome at several different time points will enable an assessment of whether the bacterial population in the equine uterus is stable over time. Taking factors such as age, treatments at the time of breeding, stallion choice and reproductive status into account will allow correlation of these factors with any changes in the microbiome.
4) assess the microbiome of the stallion’s penis.
The assessment of the microbiome present on the stallion’s penis at different time points during the season will allow us to elucidate whether the stallion has a role in the transfer of microorganisms between mares. If this is found to be the case, changes to management recommendations might result.