Iowa, Alabama, Kentucky, Nebraska and Oklahoma say they will join a lawsuit filed by Missouri's Attorney General against the state of California over hen-housing regulations. California's lawmakers passed legislation requiring all eggs sold in the state to meet larger hen cage requirements established by a 2008 ballot measure by 2015. The six egg-producing states currently involved in the suit argue the California law violates the Interstate Commerce Clause of the Constitution, and could serve as the basis for expansion into similar legislation regarding livestock and other agricultural products.