CEPS/Veterinary Extension
2938 Vet. Med. Basic Sciences Bldg.
2001 S. Lincoln Ave.
Urbana, Illinois 61802
Phone: 217/333-2907

By Kimberly Meenen
Information Specialist
University of Illinois
College of Veterinary Medicine

By providing your breeding stallion with basic horse health care and special reproduction attention, you'll be doing your best to ensure that he performs at his maximum reproductive capacity.

According to Dr. Ted Lock, an equine veterinarian at the University of Illinois College of Veterinary Medicine at Urbana, good nutrition and a sound, preventative health program designed by you and your veterinarian are important to breeding soundness.

A maintenance ration such as you would put any horse on is also adequate for your stallion. It should include pasture or good quality hay at 1.0 to 1.5 percent of the animal's body weight, grain as needed to maintain good body condition, trace mineralized salt, and fresh water.

"Stallions used heavily during the breeding season may need extra nutrition," says Dr. Lock. "Monitor your particular stallion's condition closely since there can be a great deal of variation between breeds and individuals." Supplements probably aren't necessary if the animal is on a balanced diet with appropriate energy intake. Obesity should also be avoided since it may affect mating ability and libido (the stallion's response to a mare in heat), he says.

Provide the animal with controlled exercise as needed to prevent boredom and stall vices, or to make some aggressive stallions more manageable. However, Dr. Lock notes that stallions with decreased libido may benefit from reduction or elimination of daily exercise. He suggests doing what is best for your particular stallion.

Dr. Lock advises that breeding stallions be put on the same basic vaccination program as other horses on the farm. Ask your veterinarian about which vaccines and intervals are appropriate for your area and situation.

"Finally, institute a complete parasite control program designed to fit the needs of your farm," he says. "Besides regular dewormings, it should also include good pasture management and monitoring the effectiveness of the program through fecal checks."

Now that your stallion's basic health needs have been met, you can begin to think about his reproductive soundness.

Stallions need appropriate management and health care from birth in order to be reproductively sound, says Dr. Lock. Recognize that certain things can be done to an animal when it is young to enhance its athletic performance or "centerfold" look that can be detrimental to its breeding capabilities that a prospective buyer isn't going to know about. That is why you absolutely need to have a breeding soundness exam (BSE) performed by a veterinarian before a stallion is purchased.

When a BSE is performed as part of a pre-purchase exam, keep in mind that the stallion to a certain extent exhibits seasonality just like the mare, so the stallion's lowest sperm output will be during the off-season (fall and winter). Likewise, schedule an annual BSE just prior to the breeding season.

Dr. Lock considers an annual BSE to be worthwhile, even though a stallion's breeding soundness is really evaluated during the breeding season by the number of mares conceiving.

The BSE consists of a general physical exam and history, looking for lamenesses or the presence of heritable conditions which may affect the stallion's breeding ability or desirability as a sire. Previous libido, mating ability, and fertility should be noted. Next, the external and internal genitalia are evaluated, and semen is collected with an AV (artificial vagina) so that volume, concentration, morphology (shape), and motility can be measured. Dr. Lock reminds stallion owners and prospective stallion purchasers that there are limitations to the BSE. That is, it is possible to have good semen quality but obtain low fertility.

In order to ensure adequate fertility in their stallion, owners should try to book no more than 40 to 50 mares per breeding season. If you find your stallion's book is well in excess of that number or your stallion is breeding mares as well as actively performing, you may want to consider AI (artificial insemination). Check with your
breed association to find out if this technology is approved for your breed.