Where Does the Horse Get Its Energy?

Horse owners tend to think that grain is the best source of dietary energy for horses. However, the most natural food for horses—pasture grass—actually contributes an enormous amount of energy for everyday use.

When forage is fermented through the action of bacteria in the horse’s hindgut, this digestive process produces short chain fatty acids such as acetate, propionate, and butyrate. These acids are absorbed from the horse’s cecum and colon and provide as much as 70% of the horse’s energy.

Horses asked to perform moderate or high levels of exercise will usually need more energy than what can be provided by forage. Grain meals provide hydrolysable carbohydrates from starch that is digested in the small intestine. This starch is transformed to glucose and transported across the intestinal membrane into the horse’s bloodstream, which then carries this fuel to working muscles.