Question

What are the pros and cons of feeding whole corn and oats?

Answer

Cereal grains are an excellent source of calories for horses that require more digestible energy than can be supplied by a forage-only diet.

Calories supplied by cereal grains such as corn and oats are derived predominantly from starch. Oat starch is more digestible in the small intestine than corn starch, and this feature makes oats the safer feed choice when large amounts of cereal grain must be fed. Oat starch reduces the risk of hindgut acidosis, which is caused by starch entering the hindgut and undergoing rapid fermentation.

Corn processing (cracking, rolling, or steam-flaking) improves the digestibility of corn starch, whereas processing oats does not improve the digestibility significantly to warrant the additional cost. Corn is the more energy-dense cereal grain on an equal-weight basis due to oats having more low-quality fiber, namely the oat hull that is poorly digested by the horse.

The biggest downside to feeding either straight oats or straight corn is the inverted calcium and phosphorus ratio, and neither cereal grain provides complete nutrition. To correct these nutrient deficiencies, it is necessary to feed a ration balancer pellet in combination with the cereal grain.

When feeding straight corn it is important that you purchase good-quality corn from a reliable source that has had the corn screened for mycotoxins. The risk of mycotoxins is not as high with oats. When weighing the positives and negatives of feeding corn or oats, the price of the cereal grain based on your location may be a factor.

If you are feeding a high-level performance horse that requires a significant amount of calories, I would recommend selecting a commercially made performance feed over feeding straight oats or corn. Why? Feed manufacturers utilize a combination of high-quality ingredients that offer multiple energy sources including starch from cereal grains, fermentable fiber from ingredients such as soy hulls and beet pulp, and added dietary fat that benefit the horse and reduce the risk of digestive disturbances due to feeding a high-starch diet.