Originally posted by DaTo:

Update for everyone.
After experimenting a bit, I conclude that the boars's AI was probably tweaked so that now they won't clip to each other when turning their bodies.
This makes current boar spawner design obsolete because the boars are packed so tight that they cannot turn their bodies to eat food . Even putting food right in front of them doesn't work.

Well, that means we need a new design for the boar industry.

Yes quite true, walls of 2x2, 2x4, or even 3x3 won't work. i've been experimenting a lot and looks like i found a solution for this problem. although not that efficient compared to previous designs, but this one is working.