DENVER - The mad cow scare has widened a division between some ranchers and meatpackers over a law set to take effect this fall that will require labels identifying U.S.-produced beef sold in grocery stores. Ranchers say it's more important than ever for their products to be labeled to bolster consumer confidence. Meatpackers, however, want a two-year delay in the law's implementation, contending it will require an expensive tracking system and may limit free trade without making meat any safer. Right now, consumers don't know the history of beef products in the grocery store freezer; beef produced in the...