[Ben Ficklin]

"cattle's primary food source"

That would be grass, not corn.

They feed them corn at the feed lot to add fat to the meat so that they can sell them as choice or prime. The article begins by saying select beef, which was not fed corn, is going up.

[Yosemitest]

Wrong>
Commercial raised beef are penned and fed dried corn grain, under a roof, to speed up putting on weight, and preferably Iowa Grain corn.