Quote from bluevein
hmm.. not much need to breed sheep now. All you need is 1 of every color and you can shear them any time they are woolly... I hope sheep need to eat Tall Grass to grow wool (not normal grass block like in inDev) so you have to at least bonemeal the ground to make it grassy or migrate them to get more wool. There should be some kind of farming element to it imo.
Also: Make killing sheep give you bones
Make cows refill their milk by eating grass
Make chickens only lay eggs after they've eaten grass
Pigs would still need an additional function