As part of the Food Safety Modernization Act, the FDA has proposed extensive regulations governing use of spent grain for animal feed. The Brewers Association recently issued a statement on the FDA animal feed proposal.
via Brewers Association http://www.brewersassociation.org/pages/media/press-releases/show?title=statement-from-the-brewers-association-on-fda-proposed-rulemaking-on-spent-grain