By Dr. Heather Beach

Proper feeding and nutrition is a key component for all performance horses and the same is true for breeding animals. Optimizing nutrition and body condition in the off season will ensure that your breeding stallion is in the proper condition for a healthy and productive breeding season. Most of this work needs to be done in advance of the breeding season and it is important to tailor the diet to the individual needs of your breeding stock rather than sticking to a “one size fits all” feeding program.

Optimizing Body Condition

Inadequate nutrition and over-conditioning can negatively affect fertility. In general, breeding stallions should be fed and managed so that they can maintain an overall body condition of around 5 or 6 before, during, and after the breeding season. Stallion managers need to consider many factors to maintain this ideal body weight over the season. The stallion with ideal body condition has ribs that are not visible but are easily felt. While stallions commonly have a prominent crest in their necks, they should not have excessive fat pads. The neck and the shoulder should show definition and they should not have excessive fat accumulation over the loins or by the tail head.

Stallion managers should deliberately evaluate body condition at least once or twice monthly, especially leading up to and during the active breeding season so that any needed adjustments to the diet can be made. Breeding stallions can be fed as any other performance horse–the general guideline of 1.5-2% of body weight in forage per day should provide the bulk of the horse’s nutritional needs. A commercial diet or ration balancer should be fed per company recommendations to provide additional energy and micronutrients as needed to balance the forage portion of the diet.

For Stallions

Breeding can be considered “work” so even for breeding stallions who are not also competing in sport, we have to consider an energy allocation for the work of breeding mares or being collected (most of this energy will be spent in activities outside the breeding shed as the breeding stallion tends to expend more nervous energy in general). This energy expenditure is typically the equivalent of “light work;” however, this will vary by stallion. A hard keeping stallion who tends to use a lot of energy during breeding season may need to be maintained at a body condition score of 6 or 7 heading into breeding season in order to maintain optimal weight and fertility.

Supplements for Stallions

As is the case with the overall equine supplement world, there is there is limited definitive scientific research into the effects of various supplements intended to boost stallion fertility. Vitamin C and Vitamin E both have antioxidant effects and some limited studies in humans have shown promising results in improving sperm quantity and motility. These results have not been consistently reproduced in the stallion, however. In the stallion, a combined supplement including vitamin E, zinc and selenium was studied and found to improve sperm quality. There is additionally good evidence suggesting that supplementation of stallions with DHA (docosahexaenoic acid) which is an Omega-3 fatty acid can improve semen motility of frozen or cooled semen, particularly for stallions with known motility issues when frozen or cooled. This supplementation needs to begin at least three months prior to the breeding season however, since the entire process of spermatogenesis (where the DHA supplementation will have an effect) takes approximately 65 days.

Beware Over Conditioning

Stallions who are not also pursuing athletic careers are especially susceptible to being over conditioned. Stallion managers, in an effort to make their stallions appear glamourous for advertising photos and videos, may add fat cover in place of true muscling. One of the downsides to this strategy, however, is that overweight stallions are more likely to have reduced libido. Older breeding stallions can also be at increased risk for sudden death immediately after breeding from aortic rupture. While the exact reason and risk factors for this condition are not well known, researchers theorize that the increased blood pressure from the act of breeding contributes, and possibly that unfit overweight stallions are more prone to this fatal condition. Whenever possible, breeding stallions should be kept in light work with special attention paid to maintaining suppleness, strength and comfort of their back and hindquarters. Back pain and hindlimb lameness can significantly impact stallion libido and being overweight and unfit can predispose them to injury or joint pain.