In the event you're looking for good reason why we should avoid eating grains (or grain fed livestock):
From Corn Belt To Main Street: The Drought's Far-Reaching Grasp : NPR
^The 2012 draught has been officially declared in continuation by the USDA as of 1/9/13. Meaning less crops, less feed for livestock, farmers potentially having to sell of their stocks, etc. etc. etc. It does affect food prices but we don't see it hit as hard like it does overseas. More importantly, susceptibility to disease:
Farmers on the lookout for aflatoxin as drought continues
The allowable limit by independent farmers is usually even lower then the FDA's guidelines as to prevent crop destruction. In these days of GMO, if one plant is sick they all get sick because of lack of genetic variation. All said and done, it's just more evidence to the argument that man has no reason to be eating monocrops. With that being said, we really shouldnt be eating beef, pork, or poultry fed grains either.