Horses are superbly adapted herbivores. From their wide flat molars–designed for grinding tough, gritty stems–to their gastrointestinal tracts–which process the nutrition bound in fibrous plants–they are equipped to get the maximum benefit out of food sources that many animals reject. Evolution also has provided horses with a talent for speed, equipped them with eyes set high on the sides of the head (the better to see approaching predators while grazing), and given them a preference for a herd lifestyle, to help survival while wandering the open grasslands that are their chief foraging habitat.

Our domestic horses don’t, as a rule, have the luxury of roaming for hundreds of miles in search of choice grazing. Confined to stalls and paddocks, they rely on us to provide the forage they need. For a good part of the year, when sufficient pasture is not available in many parts of North America, that means we give them hay–grasses and/or legumes that have been sun-cured, dried, and baled for convenience.

Defining Forage

Forage is loosely defined as feed with a minimum fiber content of 18% and a relatively low dietary energy, or DE, content, made up of the stems, leaves, and stalks of plants. Forage is the most natural, least expensive, and safest feed for horses, and it should be the basis of all horse feeding programs. It provides the bulk of nutrients horses require for their everyday maintenance metabolism, and stimulates the muscle tone and the activity of the gastrointestinal tract. Horses with inadequate amounts of forage in their diets run the risk of colic and founder, as well as developing stable vices derived from having too little on which to chew