US orders testing of milk supply for bird flu

The U.S. issued a federal order on Friday mandating that the national milk supply be tested for bird flu, Agriculture Secretary Tom Vilsack told Reuters, as authorities seek to grapple with rapid spread of the virus among dairy herds. Bird flu has infected more than 500 dairy herds in top milk state California, and more than 700 nationwide since March, according to the U.S. Department of Agriculture, raising concerns of the impact to farmers and the milk supply as well as the risk to human health from ongoing spread.