Feeding before you ride:
The rule of “never try out anything new at a ride” also applies to nutrition. Try not to provide more than a few pounds of any feed which is not routinely fed at home, as abrupt changes in feed, along with the stress and dehydration which often accompanies any competition, may contribute to incidence of colic. Begin nutritional preparation for a ride several days before leaving home. Encourage maximum intake of forages, especially beet pulp, as clinical trials have demonstrated that a combination of hay and beet pulp provides a significant reservoir of fluid and electrolytes in the hindgut to draw upon during exercise. As the movement of forages through the digestive tract takes several days, forages should be provided in abundance several days prior to the ride. Continue to provide forage free-choice during transport, as soon as you arrive at base camp and throughout the night. Long-stem hay is preferable over cubes or pellets as the added bulk will help maintain gut motility.
It is best not to feed large amounts of grain within four hours of the start of the ride, as the glucose peak produced during digestion of simple carbohydrates adversely affects the utilization of body fats needed during a long day of exercise. Providing a few pounds of grain for a day or two prior to the ride is more than sufficient to “top up” glycogen stores within the liver and muscles. However, adding a handful or two of grain for flavor to an overnight beet pulp mash will do no harm. The point is to avoid large grain meals immediately before exercise
Do not add fats immediately before or during the ride. Although it would seem like a good source of energy, a high fat ration tends to decrease forage intake needed to maintain motility and hydration. The relatively small amount of fat in commercial grain mixes (even “high fat” formulations) is not a concern.
Especially in hot, humid weather, significant amounts of electrolytes are lost in the sweat. Sodium, chloride and potassium are the primary ions lost, along with smaller amounts of calcium, magnesium and other trace minerals. Increasing scientific data indicates that supplementing during exercise, and thereby minimizing depletion, is beneficial in possibly averting metabolic problems such as thumps, tying-up, poor gut sounds and other symptoms associated with “exhausted horse syndrome.” The body does not store excess electrolytes against future need, therefore “pre-loading” several days before a ride will not replace supplementation during the ride itself. However, orally syringing a day or two before the ride (especially before and during transport) may help trigger a “thirst response” to encourage drinking. Likewise, supplementing throughout the day may encourage drinking as well as replace electrolytes lost through sweating.
As with every other feed supplied throughout an endurance ride, small and frequent amounts are usually preferable to large and infrequent. Electrolytes are often added to feed or water, but some horses may refuse too salty a flavor, and therefore also refuse much-needed food and water. Although horses do develop an appetite for needed salt to replace depleted stores, this is not an instantaneous response. Don’t rely on this mechanism during a ride! Oral syringing is a good alternative that has worked well for many horses and riders. Take advantage of the increasing body of scientific data and consider the use of research-based electrolytes formulated specifically for endurance horses
Feeding after you ride:
Once you’ve successfully crossed the finish line and received your final control check, don’t assume the energy demands of the day are over for your horse. Depending on the length and intensity of your ride, it can take days or even weeks to fully replace the fluids, calories and nutrients used during competition. Allow your horse plenty of opportunity to drink his fill to replace lost fluids, including during the trailer ride home. Provide plenty of forage free-choice. The “stress hormones” produced during exercise may continue to deplete the body of electrolytes for several days following the ride and continued supplementing with electrolytes may help ensure a quick recovery. Research has suggested that glycogen repletion is increased during the 24 hours following strenuous exercise and may help avoid sore or stiff muscles. Small amounts of grain every few hours—not exceeding his normal accustomed amounts—are helpful, as long as your horse is not unduly dehydrated or experiencing metabolic trouble. If you are in doubt about gut motility, check with the control judge or treatment vet before feeding anything other than forage and water.