At the National Association of State Departments of Agriculture (NASDA) winter policy conference in Washington this week, animal welfare was among the topics covered. In particular, the California ban on battery cages for egg layers. Back in 2008, California voters passed Proposition 2, which prohibits the confinement of certain farm animals in a manner that does not allow them to turn around freely, lie down, stand up and fully extend their limbs. The measure deals with three types of confinement: veal crates, sow gestation crates and, most prominently, battery cages (California is a significant player in egg production). Implementing the statute has been a difficult task for California. To protect its own producers, the Golden State has...