WASHINGTON - Investigators may never figure out where the Alabama cow with mad cow disease was born and raised, in part because the U.S. lacks a livestock tracking system the Bush administration promised two years ago. After the first case of mad cow disease in December 2003, the government pledged to get a nationwide program into place quickly so officials could track cows, pigs and chickens from their birth to the dinner table. Today, however, the system is a long way off. Alabama officials saw the need firsthand last week as they tried to discover where the infected cow came...