Horses are herbivores because they eat primary producers. Primary producers are organisms that are able to produce their own food using chemical energy or energy from the sun.
The digestive system of the horse was designed to process high-fiber foods. As a result, horses are able to eat grass, hay and grains. Some horse owners give their animals mineral supplements as well. Horses have small stomachs, so they eat small, frequent meals instead of large meals. If a horse consumes too much food in one sitting, there is a risk of stomach rupture.
Because horses eat primary producers, they are classified as primary consumers. Primary consumers play an important role in ensuring the survival of an ecosystem.