Usually this question is focused on dogs. Sheep are grazers so they might try and eat some especially if they are young. I don't know if sheep are poisoned by hops like dogs. Some cheap fencing might be a good investment. Maybe someone with sheep can help out more.
............Alright Brain, you don't like me, and I don't like you. But lets just do this, and I can get back to killing you with beer......~Homer