From the Summary: "Many animal producers support establishment of a nationwide identification (ID) system capable of quickly tracking animals from birth to slaughter. While they believe such a system is needed to better deal with animal diseases or meet foreign market specifications, some consumer groups and others believe it also would be useful for food safety or retail informational purposes -- and that the program should be able to trace meat products through processing and consumption. However, despite years of effort on at least an animal ID program for disease purposes, many contentious issues remain unresolved. For example, should it be mandatory or voluntary? What types of information should be collected, on what animal species, and who should hold it, government or private entities? How much will it cost, and who should pay? Following the first U.S. report of a cow with BSE (bovine spongiform encephalopathy or 'mad cow disease') in late December 2003, the Secretary of Agriculture promised to take the lead in implementing an animal ID program capable of identifying all animals of interest within 48 hours of a disease discovery (BSE or other). The U.S. Department of Agriculture (USDA) has committed, through FY2006, $85 million to this effort, and all states now have systems for registering animal premises."
CRS Report for Congress, RL32012
National Agriculture Law Center: http://www.nationalaglawcenter.org/