(Reuters) – Hard-hit livestock and poultry producers petitioned the government on Monday to reduce or cancel the required use of ethanol in gasoline for a year, asking for “a little help” to ride out the worst drought in 56 years.

The request for a first-ever waiver from the federal Environmental Protection Agency’s mandate, which in essence requires that more than a third of the U.S. corn harvest be converted into ethanol, comes as grain prices have surged to record highs, driving up feed costs and squeezing profits for producers.

“We are having trouble buying corn… it’s really putting a burden on our operations and many others across the nation,” says J.D. Alexander, president of the National Cattlemen’s Beef Association, whose Nebraska feedlot is about half full of cattle. “It’s time to wean the ethanol industry and let it stand on its own.”

The EPA has not granted a waiver since the Renewable Fuels Standard (RFS) was enacted in 2007. The policy has enjoyed years of staunch bipartisan support, boosting income for U.S. farmers and helping reduce the country’s dependence on foreign oil. But it is now coming under renewed attack.

Matt Hartwig, a spokesman for the Renewable Fuels Association, said the move by the  beef, chicken, pork and turkey trade groups “is not an official waiver request — and did not trigger EPA to begin the process.”

The only groups that can petition the EPA for a waiver are oil refineries or blenders, a state or the EPA itself.

Corn prices have risen 60 percent over the past six weeks.

About 35 percent of the U.S. corn supply is now used to produce ethanol — about the same amount that is used as animal feed, according to the U.S. Agriculture Department.

Two-thirds of the country is suffering from moderate to exceptional drought.

(Additional reporting by Christine Stebbins in Chicago.; Editing by Dale Hudson, Bob Burgdorfer and Andrew Hay)