Animals won't spawn, even though on an older map they will

I fenced in 16 sheep on my map, and know there are no more animals spawning. I killed oned to see if that would do anything (a while ago), but that hasn't done anything. I've looked all over the map and havn't seen any animals spawn, so should I just kill the rest of my sheep and see if that does anything?

Solution 1:

As of Minecraft Version 1.3.2, The spawning algorithms have changed so that animals (passive mobs) are generated once per chunk, and do not despawn. Angered wolves and ocelots are the exception, as by definition they are not passive. Also, squids retain the previous 'spawn anywhere' code.

See the answer here: How does animal spawning work?

If you want more animals, you will need to breed them, or search further from your base in newly generated chunks to find more.

You can breed animals by feeding two of them food. They will then 'kiss' for a little bit, and a baby animal will be created. (which will eventually grow up). The food you need to feed them is as follows:

• Sheep: wheat
• Cows: wheat
• Pigs: carrots
• Chickens: seeds (wheat, pumpkin, melon, or nether wart)

Note this is also the food that (when held) will make the animal follow you around.