Hoof is a hard growth on the feet of many mammals. These mammals are sometimes called ungulates. They include pigs, zebras, horses, and the horned mammals. A hoof is made of horn, a substance developed from the epidermis (outer layer of skin). The hoof differs from a nail or claw because it is blunt and it encases the toe or foot. Hoofed mammals may be divided into those with even and odd numbers of toes.
The horse’s hoof developed on a single toe. It almost completely circles the bottom of the foot. Asses and zebras also have single toes. The even-toed animals never have more than four toes. Usually, the two middle toes form a cleft (divided) hoof. This group includes deer, antelope, sheep, goats, cattle, pigs, and the hippopotamus. Hoofs give the animal a firm footing and protect its feet. Some animals can use their hoofs to defend themselves.
