Iowa Sen. Tom Harkin has asked the Government Accountability Office (GAO) to investigate USDA's plans for the National Animal Identification System (NAIS).

In a statement, the senator pointed out that after two years, USDA has yet to implement an animal ID program, and has failed to inform producers and state governments about the costs of such a system.

The goal of NAIS is to support state and federal animal disease monitoring and surveillance through rapid traceback of exposed animals during an outbreak.

As of early November, 147,205 premises have been registered in the national ID program.