Tyson Foods Inc. and Pilgrim's Pride Corp said they were substituting some corn with wheat in rations in the east, where corn prices have risen the most due to tight supplies.
"It's pretty rare. Usually you have to have some kind of super harvest in wheat and a bad harvest in corn. There just has to be some unusual line-up of the stars for this to happen," said economist Paul Aho at consultancy Poultry Perspective.
A National Chicken Council spokesman said that some additives would have to be added to the feed in order to maintain the same nutritional aspects as corn feed, but the taste of the meat would not be affected.
"Tyson is currently using limited amounts of wheat. We would like to use more but supplies are tight," Tyson spokesman Gary Mickelson said.
Pilgrim's Pride, the No. 2 U.S. chicken producer, said it had started feeding small amounts of wheat to chickens at certain locations in the eastern United States.
"We have recently begun incorporating some small amounts of wheat into our feed formulations in selected locations in the east, not the entire company, to help save money," Pilgrim's Pride spokesman Gary Rhodes said in an email.
Pilgrim's Pride also is using distillers' dried grains, a corn byproduct of ethanol production. Sanderson Farms said that it is currently not using wheat, but it is evaluating its use.