Few issues are more frustrating for a stud than a stallion with unexplained subfertility. The financial implications, management pressure, reputational impact, and disruption of an entire breeding season can be substantial.
What can be even more challenging is when standard semen analysis appears ‘normal’. Progressive motility is good, morphology is acceptable, sperm counts are adequate, and sperm viability is good- yet conception rates remain disappointingly low.
In these situations, it can be easy to attribute the issue to mares, timing, or management. However, when poor pregnancy rates persist despite careful mare selection, intensive reproductive management, and thorough veterinary oversight, it is generally indicative that the fertility issue lies with the stallion. These cases seem to have no clear answer, and the stallion is subsequently categorised as having ‘poor fertility’, which is deemed idiopathic.
Yet, there are answers. And for Thoroughbred stallions in particular, one factor which historically hasn’t been easy to identify is impaired acrosome exocytosis (IAE). This results in sperm failing to release necessary enzymes to properly fertilise a mare’s egg, despite sperm appearing normal on routine semen evaluation.
While this diagnosis can initially sound concerning, it also provides valuable direction for studs who are struggling with these stallions. There is much which can be done with judicious use of specific therapeutic nutrients, herbal medicines and dietary interventions to help these stallions and improve their fertility and conception rates.
Stallion fertility and breeding performance can be supported at any stage of the year. While the ideal time to investigate unexplained fertility concerns and proactively optimise reproductive health is several months before the breeding season, valuable improvements and practical support can still be achieved immediately prior to, or during the breeding season itself. If you are managing a stallion with suboptimal fertility, unexplained poor conception rates, or would like to explore integrative reproductive support strategies ahead of the season, please feel free to contact Optim Equine directly for a confidential discussion.
FREE Fertility eBook
Enter your email below and learn about five ways you may be inadvertently harming your stallion’s fertility and what you can do to about it.
Your FREE eBook will be emailed to you shortly after submitting your email.
Camilla Whishaw is a highly regarded, experienced horsewoman and naturopath, helping to holistically treat and manage a broad range of equine health conditions and injuries, with a passion for mare and stallion fertility.
As a world-renowned practitioner, presenter, author, and consultant in the field of Equine Naturopathy, Camilla shares her knowledge through keynote presentations, interviews, lectures, panel sessions, and workshop training.
