The future of state laws that regulate everything from the size of a hen’s cage to the safe consumption of Gulf oysters may be at stake as farm bill negotiators work to resolve a long-simmering fight between agriculture and animal welfare interests. The House Agriculture Committee added language to its version of the farm bill earlier this year that says a state cannot impose certain production standards on agricultural products sold in interstate commerce. The provision, authored by Rep. Steve King, R-Iowa, is aimed at a California law that will require all eggs sold in the state to come from...