My best friend has two mini donkeys in with Babydoll and Jacob sheep and a goat. They seem to do well together. The field isn't huge. I'm guessing maybe half an acre but I'm not a good judge of that stuff. The only prob she has had since she got them last Fall was ringworm around their eyes. Also she bought two and was told they do better in pairs. she has two males and recently had them gelded. They are really sweet and easy to manage.