In the absence of water and fat, protein makes up 80% of the horse’s body and is found in hair, hoof, skin, muscle and blood cells. Protein is also a major part of hormones and enzymes used to control many physiological processes.
The amount of protein required in a horse’s diet depends on the individual needs of the animal, the quality of protein being fed, and the amount of feed the horse is eating.
Protein requirements are highest for young horses due to growth and the fact they cannot eat large amounts of feed.
Protein requirements are the lowest for mature horses in maintenance situations, since they are not actively growing and have a large feed intake.