Barnyard (2006)

Otis is a mischievous, carefree Holstein cow who lives on a farm where, unbeknownst to humans, the animals are anthropomorphic. He prefers having fun with his best friends: Pip the mouse, Freddy the ferret, Peck the rooster, and Pig the pig - rather than following strict rules and accepting responsibility. But when his adoptive father is killed in a coyote attack, he has a heavy responsibility thrust upon him to become leader of his farm home's community.