Farm animals are being fixed, since the bug was finally identified.
1) some ranges are in xml, some are harcoded. I can tell you out of my head that plants look for water in a 7 block radius, and NPCs look for food either inside their own inventory or in a 16 block radius, give it or take it... It's a good idea not to have too many fridges near survivors, since they will look for the closest one, and it's harder to keep multiple fridges with the correct supplies... Also remember they don't need direct access to it, like the animals, so they may find one on a different room and try to use that one... I will review this procedure when possible.
2) there are a few way actually: find the farmer npc and finish the quest, be lucky enough to loot one (VERY rare and only drops on one place), or be lucky enough to get one on Pacco's slot machines. Quest can only be done once, but you can loot more then one... They are not currently breedable, but since Tormentedemu is making nice stuff with mounts, who knows

maybe they'll get to be a lot more useful in the future.
IMPORTANT NOTE TO EVERYONE: next patch will bring weather seasons. It will all be configurable via xml, so that server managers or individual players can opt out of it or configure their own season distribution. The patch is not far away, so I thought I would give a heads up to let you guys discuss that with your groups to make a decision before it drops.