Four Main Types of Essential Nutrients of Horse Feed

Water

• The average, non-working horse drinks 10 to 12 gallons of water daily; that amount will increase with exercise. This necessitates that horses have fresh, clean drinking water available to them at all times to keep them properly hydrated. A dehydrated animal is more likely to colic with fecal impaction, a potentially deadly problem, because the horse's intestinal tract requires large amounts of water to function normally. Hot, sweating horses lose electrolytes (sodium, chloride and potassium) as well as water--resulting in conditions where the pH levels in the blood become higher than normal and the animal's muscle and organ functions are affected. A full water supply plus mineral supplements should supply all the electrolytes needed by the average horse.

Protein

• Protein requirements in horses will vary according to the needs of the individual horse and the quality and digestibility of the feed. Adult working horses, pregnant mares and foals call for more protein than do older "pasture pets." Composed of amino acids, proteins form a large part of body mass, including all cell membranes, connective tissues, hormones, muscles and blood. A typical working horse needs at least 12 percent protein in feed and forage to maintain stasis (normal cell function). A deficiency of dietary protein in a foal results in small, disease-prone animals. In adult horses, the lack of protein shows in poor hair coat, tissue wasting and unhealthy hooves.

Carbohydrates and Fats

• Carbohydrates found in forage and grain provide the equine body with its primary source of energy. The horse's liver breaks down some ingested carbohydrates into starch, maltose and sucrose, which are then used for energy or converted into necessary enzymes and biochemicals. Glycogen carbohydrates stored in the liver function as catalysts for muscle contractions and movement. The remaining carbohydrates of cellulose and hemicellulose carry out fermentation in the horse's gut, releasing fatty acids that convert into energy.

  Adding fats to the horse's diet increases performance and preserves body condition by utilizing energy that does not draw on the horse's stored body fat. A concentrated form of energy, dietary fat contains "2.25 times more energy per unit of weight than do carbohydrates or proteins," says Rick Parker in his book "Equine Science." Owners of working horses often maintain weight and energy levels by adding corn oil to the animal's normal rations.

Vitamins and Minerals

• Horses require a variety of vitamins depending on their age, muscular activity and overall health. A diet of high-quality pasture grass plus grain feed and adequate water usually provides the necessary nutrients. Fat-soluble vitamins A, D, E and K are needed for optimal vision, mineral absorption, a competent immune system and blood clotting. The water-soluble vitamins of thiamine, riboflavin, niacin, biotin, pantothenic acid, choline, ascorbic acid (vitamin C) and vitamin B-12 can be found in the horse's feed, but are also synthesized by healthy flora in the animal's intestines. These vitamins metabolize energy and function in the horse's body as cellular enzymes.

  Classification of minerals in the equine body depends on the amount required. The seven macrominerals include calcium, potassium, sodium, phosphorus, chloride, magnesium and sulfur. Copper, iodine, iron, selenium, cobalt, manganese, fluorine and zinc comprise the eight microminerals (trace minerals). Horses use minerals at a cellular level to metabolize energy, build muscle and bone, maintain fluid and acid-base balance, and provide adequate absorption of oxygen in the animal's blood.