I play a server on the snapshot with an automatic chicken farm. I logged in with the new shapshot (14w06a), and near all the chickens have escaped. The container they are in is made out of glass, which my be the bug. The container has an opening at the top but it's too high for them to reach.
MC-47530
Chicken Through Glass
Resolved
Duplicate
0
Given this and MC-47518 (and others), I'm thinking some of the clipping logic has changed in 14w06a that is causing either a) escapes, b) deaths, or c) insane clipping glitches (that is me with a high-efficiency cow breeder).