Kathleen Crandell, Ph.D., a nutritionist with Kentucky Equine Research, shared her extensive knowledge of feeding endurance horses with the audience at the 17th KER Nutrition Conference.
Crandell gave a brief overview of endurance riding before launching into the nutritional management of these equine athletes.
Forage is a major source of energy, and provides essential nutrients and bulk for the gastrointestinal tract. Most of the endurance horses in the United States are on pasture 24 hours a day, with free-choice access to forage. Another advantage of full-day turnout is the freedom of horses to move about as they choose, which is best for muscle and joint health.
The best hay for endurance horses is usually the best hay that is available, though for endurance horses grass hay is preferred. This is primarily because legume hays such as alfalfa often have too much protein and calcium, and there is a risk for enterolith (intestinal stone) formation. Other forage choices for horses are chaff (dried chopped forage), hay cubes, and hay pellets. Super fibers, specifically beet pulp and soy hulls, can supply a significant amount of calories to endurance horses.
Starch is more concentrated in energy than fiber, so it is often used to add calories to a ration. Starch is most often supplied by cereal grains. Cereal grains are not balanced for forages, so they often require a ration balancer for optimal nutrition. A ration balancer is a low-intake feed (1 to2 pounds per day) that provides vitamins and minerals not supplied in forages. Fortified concentrates (textured or pelleted feed) best complement forages for horses that require more calories.
Sugars such as molasses and honey are often used to improve palatability of both feeds and water. It is also used in competitions to allow for quick recovery from a drop in glucose.
Fat is often included in the rations of endurance horses. These include vegetable oils, powdered vegetable or animal fat, and rice bran, among others. Fat is a more concentrated energy source than starch, so it adds calories without increasing meal size. Fat cannot be the sole energy source for endurance horses, and rarely do endurance horse rations exceed 5% fat.
Protein is not a major source of energy for endurance horses, though it is an essential nutrient. The protein requirement for the average endurance horse is 8 to 10%, which can easily be supplied through good-quality forage. The highest requirement for protein is following a race when horses are rebuilding damaged body tissues.
Most endurance riders in the United States seek out high-fiber, high-fat, low-starch feeds.
The key to a successful ride is to keep endurance horses eating. Everything that will be fed at the ride should be fed in the weeks leading up to the race. Nothing new should be introduced into the diet on the day of the race as this can lead to gastrointestinal problems.