Well been trying this out in my SP Lan server...
This is pretty slick, but a couple of suggestions (maybe they have been mentioned)...
Animals still don't seem to stay penned up in the game reliably (especially chickens in a coop). A way to locate your roaming animals would be nice. Even a way to "recall" them from afar.
Maybe some way be able to tell who the owner is of a roaming pet.
Very Nice job here!