Sheep or domestic sheep are domesticated, ruminant mammals typically kept as livestock, Although the term sheep can appley to other species in the genus Ovis, in everyday usage it almost always refers to dometicated sheep. Like all ruminants, sheep are members of the order Artiodactyla, the even toed ungulates the bighorn sheep (ovis canadensis) is a species of sheep native to North America. It is named for its large horns A pair of horns might weigh up to 14 kg (30 lb) the sheep typically weigh up to 143 kg (315 lb)