Mustang horses eat a varied vegetarian diet that includes grazing on grasses and forbs, and browsing on trees and shrubs. They also consume nutrients in areas of exposed soil where salt and mineral concentrations are high.
Grass is a horse’s favored food type. Mustangs primarily eat perennial grasses, such as galleta, deergrass, bluebunch wheatgrass, icegrass and Great Basin wild rye. The rangelands of plains and deserts are plentiful in these types of grasses. Bermuda and fescue are examples of invasive grasses that have been introduced to wild rangelands and are commonly found near altered pastureland and areas of human habitation. Although these plants not as abundant as grass, horses also graze on weeds known as forbs. Common types of forbs found on rangelands include thistle, sunflower, dandelion, clover, primrose and echinacea.
Mustangs mainly eat off the ground but can also reach upward for foods like tree branches and shrubs. They eat off of broadleaf trees, such as willow, apple or maple, and evergreens, such as pinyon and juniper. According to scientists who observe the feeding habits of horses, the animals consume substantial amounts of soil because it provides important nutrients not as abundant in the rangeland diet. Nutrient-rich soils contain magnesium, calcium, sodium and potassium.