I know this HAS been submitted previously (at least once MC-19969) however it is showing as resolved - it is not.

Baby chickens will turn to raw chicken when they are due to grow to full size chickens if they are too close to a wall.

This is essentially the same thing that happened to full size animals if they were pushed into walls for long enough. This full size issue has been resolved in snapshot 1.6.2, this one has not.

I placed a bunch of full size chickens into a 4x4 space surrounded by dirt and bred 5 baby chicks, only 1 died but it was the only one near a wall.