Role of Carbohydrates in Equine Diets

A horse's overall health depends on a variety of factors, but perhaps the most important is its diet. To keep a horse in optimum condition, its diet needs to contain an ample supply of fiber-based carbohydrates.

  1. Importance of Carbohydrates

    • Horses require an abundance of energy, and most of a horse's energy comes from carbohydrates within its food. Horses get much of their required carbohydrates from fiber in hay or other types of forage. In fact, a horse's digestive system is geared toward a slow, continual intake of grass, hay and other types of forage. The horse has a large, highly developed colon that contains an array of microbes uniquely suited to ferment and break down large volumes of fiber.

    Sources of Carbohydrates

    • Forage, such as hay, is a horse's primary source of complex carbohydrates, such as cellulose, hemicellulose and lignin. Grains provide the animal with simple carbohydrates, which are important in providing a horse with energy. There are four types of carbohydrates in the typical equine diet: monosaccharides, such as glucose, fructose and galactose; disaccharides, such as lactose; oligosaccharides, such as raffinose and fructans; and polysaccharides, such as starch and cellulose.

    Carbohydrate Digestion

    • Although these different types of carbohydrates contain approximately the same amount of energy, the energy they provide after being broken down by the horse's digestive system can differ. This difference in usable energy --- called net energy --- occurs when energy is lost or used up during the metabolism process. Energy can be lost by producing heat and via urination and defecation. Carbohydrates that are absorbed as monosaccharides in the horse's small intestines will provide the most usable energy.

    Non-Fiber Carbohydrates

    • Horses will also get energy from carbohydrates contained in sources other than fiber, such as starch and sugar. Non-fiber carbohydrates are typically fed to a horse to facilitate weight gain or provide a burst of extra fuel for a race or other type of physical exertion. The horse's digestive tract, however, is not suited to processing large amounts of starch, and horse owners are cautioned to avoid equine diets that are high in sugar or starch, as this increases the risk of digestive disorders, such as colic and muscle spasms, commonly called "tying up."