Officials in the GAO report said that up to 60% of corn grown in the United States before 2006 was used in beef, pork and dairy production. But by 2008, more than one third of corn in the United States was diverted to ethanol production plants concentrated in the Midwest where the majority of the corn is grown.
http://nationalhogfarmer.com/nutrition/1217-ethanol-doubled-feed-costs/