They have four parts to their stomachs. After swallowing large amounts of food, it passes to the first stomach. Later it is brought back up to be rechewed. It is then passed to the second stomach where it begins to be thoroughly digested. The even-toed noncud chewers are the pig and the hippopotamus.
Hoofed mammals can have horns.
The cow, ox and bison have hollow horns that they never shed. The deer, elk, caribou and moose have solid, large horns that they shed.