The U.S. government will tap an additional $330 million in emergency funds to cover farmer claims related to the fast-spreading bird flu outbreak and other efforts to contain the disease, U.S. Agriculture Department sources told Reuters on Tuesday.

The money comes after U.S. Agriculture Secretary Tom Vilsack requested that the federal Office of Management and Budget (OMB) grant the agency's bid to tap emergency funds.

The additional funds, added to the $84.5 million previously set aside by USDA for the outbreak, bring the federal costs so far to at least $414.5 million. That amount is one of the largest sums the federal government has spent on a livestock disease outbreak, according to government data.