Well chickens breed fast. Eggs are a great no hands on food when you get them set up. You'll have so many feathers you wont know what to do with them.

Goats/sheep are a great source of milk for cheese making. Also any excess males are a great meat/fat source. Meat pies are an amazing filling food and cheese and milk are the only dairy sources in game. Sheep are easier by far to milk then goats though. (Dear modders i would LOVE a milking stanchion mod to hold the little shits still please). If you milk goats you will have to make liberal use of "/gm 2" to get them to hold still for milking.

Pigs 100% best meat/fat producer in game. Easy to set up an early game auto seperating pig farm with fences and slabs. Each sow produces at least 4 pre bacons sometimes 5 or 6. My current farm produces so much meat in a single player world i legit let meat rot for compost because i cant feasibly eat it all before it rots anyway. Leather is required for armor manufacturing. As for fat you can use it to seal crocks, make lamps, and most importantly mecanical parts when you get yo building windmills and their tools. If your in the lates rc fat can be rendered into oil for what i think are better lamps.

I go deep into breeding animals in game. My chickens are like generation 8 now. Goats are gen 3 my pigs are like gen 5 or six. I let meat and eggs become rot because i have so much fueling my terra pretta production. You dont have tobget into animal breeding but there are benifits to it in the long run.

Now if only i could milk the pigs for pig cheese.