Keeping Horses Cool with Small Changes in Diet

Other than purchasing portable misting fans or hiring a loin cloth-clad individual to fan your horses with palm leaves, what other strategies can be used to keep horses cool in warm weather? Small tweaks to your horse’s diet can reduce his internal combustion.

Some horse feeds produce more heat than others while being digested. For example, cereal hays and chaff produce much more heat during fermentation in a horse’s hindgut than barley, oats, or corn being digested in the small intestine. In addition, protein digestion produces as much as six times more heat than starches (like corn and barley). Fat, on the other hand, produces very little heat because enzymes break fat down in the small intestine (rather than being fermented in the hindgut, like hay).

What can be done to help horses stay cooler in the heat? Small changes in the diet can make a big difference. For healthy horses that maintain optimal body condition, consider the following suggestions:

1. Offer several smaller meals instead of one or two larger feedings.

2. Decrease the amount of forage to 1% body weight. (This may require supplemental grain to maintain the horse’s caloric intake.)

3. Choose a hay or combination of hays that contain no more than 7-10% protein. Many hays naturally contain higher percentages of protein, which will generate unnecessary heat (for example, alfalfa (lucerne) contains up to 20% crude protein).

4. Use oils and fats to provide additional energy (calories) as needed.

Other hot weather-related factors to consider are location, hydration, sweating, and electrolytes such as Restore® SR from Kentucky Equine Research. Feed horses in shady places and offer drinking water with a temperature between 45° and 65° F (7° to 18° C) for maximal consumption. Hydration can also be encouraged by moistening foods. If horses are sweating heavily in the heat, consider supplementing with electrolytes. Finally, horses kept in optimal condition (rather than being overweight) are more comfortable in the heat.

As always, be certain to make transitions in the diet slowly (over 2-3 weeks) to minimize any potentially deleterious effects on the digestive system.