Marion Nestle, I think Michael Pollan would disagree with you.
There are a host of problems with industrial farming, including environmental pollution, says Nestle, but eating animals raised on corn diets is not one of them. "It would be too bad if this adds to public fears about corn," she says.
Cows are ruminants. They are not supposed to eat corn. It makes their meat more fatty (which makes people that eat it more fatty), and adds to the terrible corn monoculture that has taken over the midwest.
Article:
http://health.msn.com/nutrition/articlepage.aspx?cp-documentid=100220333&page=1