Corn is a low-cost feed choice for energy and weight gain in horses. In feed it is usually cracked, but can be fed on the cob, or as whole shelled corn. Actually, cracking corn is economically wasteful. Because of the size of the kernel of corn, a horse will chew the grain before swallowing. If a horse is passing many whole kernels in the feces, he either is bolting his feed or may need to have his teeth floated because sharp points are preventing normal chewing. Feed corn carefully to prevent colic from the high-energy, low-fiber content.
Corn is about 10 percent protein, but as with all grains, the protein quality is relatively poor. Corn contains more energy than an equal volume of oats. As stated by the University of Missouri Extension approximately 15 percent less corn is equal to a given weight of oats in energy value.
Corn is rich in vitamin B, especially thiamin and niacin. Thiamin is vital for cognitive function and maintaining nerve health. Niacin is broken down in the cecum and colon, although there is no dietary need for niacin in the horse’s diet. Corn is also an adequate source of pantothenic acid, a vitamin needed to metabolize carbohydrates, proteins and lipids in the body. The kernels of corn are rich in vitamin E, a natural antioxidant essential for growth.
Fats are easily turned into usable energy when consumed by the horse. In addition, fats in a horse’s diet help to improve coat condition and facilitate the absorption of fat-soluble vitamins. Corn contains 3.6 percent fat, thereby supplying the necessary amount in the horse’s diet.
Corn contains an abundant amount of phosphorus, magnesium, manganese, zinc, iron and copper. It also contains trace minerals such as selenium, sodium and sulfur. Phosphorus is essential for maintenance of normal growth and kidney functioning. Magnesium is necessary for heart health and bone strength.
Corn, like other vegetables, contains a high percentage of complex carbohydrates. The digestibility of corn increases by 5 percent to 10 percent when the corn is cracked or rolled. Energy values of grains are generally expressed in terms of total digestible nutrients (TDN), with corn having a score of 80 TDN.