Snocrash | Minecraft: Smarter Redstone-less Animal Cooker @sno_crash | Uploaded 10 years ago | Updated 7 hours ago
An alternative (redstoneless) design to an Xisumavoid smart cooker, which you can look at here: youtube.com/watch?v=LFpoHkzeHfc

Good solid design which has a low resource requirement.
For pigs and cows.

Enjoy.