When some of the corn is replaced with other grain, the composition of the ration changes. A bushel of barley should weigh at least 45 to 47 pounds. Oats are much higher in protein and lower in energy than is corn. A bushel of oats should weigh at least 35 to 40 pounds. Rye is high in protein and lower in energy than is corn, but it is very expensive and not very palatable for horses.
Soft wheat is higher in protein and about the same as corn in energy.
Although a wide variety of other grains exist, most horsemen choose to feed oats. Good, heavy, plump oats that are bright in color are expensive and hard to find. Light oats with a lot of empty hulls provide no more energy than average grass hay. When good oats are used to replace some of the corn in the concentrate mixture, the protein level increases and the energy decreases. Increasing energy can be done by using vegetable oil.