Nutraceuticals to Enhance Stallion Fertility?

Do you ever wish you could give your breeding stallion a magic supplement to enhance his fertility? Science isn't there yet, but according to an equine reproduction specialist, some supplements and diet changes might help, as research has shown that some dietary alterations really do have a beneficial effect on semen quality and stallion fertility.

"A number of supplements have recently been studied that show real promise for improving the breeding performance of stallions," said Steve Brinsko, DVM, PhD, Dipl. ACT, professor and chief of theriogenology in Texas A&M University's Department of Large Animal Clinical Sciences. Brinsko presented on the topic at the 2011 Florida Association of Equine Practitioner's Annual Promoting Excellence in the Southeast Convention, held Sept. 29 - Oct. 2 in Amelia Island, Fla.

"These supplements include ingredients such as omega-3 fatty acids, the polyamines spermine and spermidine, vitamins C and E, and other antioxidants such as L-carnitine," continued Brinsko, who is also president of the American College of Veterinary Theriogenologists.

Of all of the different supplements touted to improve semen quality (ergo stallion fertility), the most recent research has focused on altering the fatty acid component of a stallion's diet, he said.

"Semen contains large amounts of lipids, which are important for the motility and fertilizing capacity of the sperm as well as their sensitivity to cold," explained Brinsko.

Two of the most common lipids in semen are docosahexaenoic acid (DHA), an omega-3 fatty acid, and docosapentaenoic acid (DPA), an omega-6 fatty acid. Studies have found that the more DHA there is in semen compared to the amount of DPA, the better.

Brinsko explained, "High DPA to DHA ratios in semen are not desirable as they are associated with reduced sperm quality and fertility."

Unfortunately, most equine diets (which are corn- and soybean-based) favor the production of DPA over DHA. Brinsko suggested one way to turn the tables is to supplement a stallion's diet with DHA and/or to alter the diet's fat content so it favors the production of DHA over DPA. This approach can result in a threefold increase in semen DHA levels, increased semen motility, concentration, and percentage of live sperm, he noted.

"It is important to note that these improvements were most noticeable in stallions that initially had poorest semen quality," cautioned Brinsko. "Supplementing the diet of highly fertile stallions does not appear warranted at this time."

Additional information about the conference and Brinsko's presentation is available online.

Disclaimer: Seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy.