Minecraft has a wide variety of meat products that you can eat. I like to eat all of them. If you want you can farm different animals in the same pit or in different pits if you want. If you eat your meat raw then it might make you sick. If you are sick you can drink milk to get rid of the sickness.Otherwise it will reduce you to having 1 health point until you regenerate the rest.
Mutton is a newer meat only put out in 1.9. You get mutton from sheep. Sheep is a great animal to farm because you can shear wool from it and you get meat so it is a win win situation. Mutton is 2 food points when raw but when you cook it in a furnace mutton becomes 6 food points.
This might be the most used meat in Minecraft because cows are really helpful. You can milk them with a bucket. And when you kill them you will get leather and beef. When you eat beef you will get 3 food points and when you cook beef you will get steak which is 8 food points.
This might be the least used meat in Minecraft because pigs only give you porkchops, nothing else. If you want them to follow you, you have to have a carrot in your hand. Porkchops give you 3 food points if raw and 8 food points if cooked.
While this isn’t exactly meat it is somewhere in that region. You get it from zombies when they die and isn’t really helpful. If you eat it you will probably get sick and you can’t cook the sickness out of it. One piece of rotting flesh is 4 food points
I hope that this helps you decide what you are going to farm animal wise.