WASHINGTON (AP) -- Livestock farmers and ranchers seeing their feed costs soar because of the worst drought in decades are demanding that the Environmental Protection Agency waive production requirements for corn-based ethanol.

The Obama administration sees no need for a waiver, siding with corn growers -- many of them in presidential election battleground states Iowa and Ohio -- who continue to support the requirement.

The livestock industry argues that at a time when supplies are precarious, the large share of the corn crop going to ethanol production is driving up prices and driving them out of business.

The Renewable Fuel Standard, enacted in 2005 and then significantly expanded in 2007, requires that 13.2 billion gallons of corn starch-derived biofuel be produced in 2012.