Check out the link below.  It indicates that the primary health problem with beef consumptions is not the beef, but the fact that most of the beef is raised primarily with corn.  Grass fattened beef appears to be very healthy.

Perhaps Iowa agriculture in the future instead of being primarily corn and soybeans,  could contain a healthy dose of well managed pasture lands, probably the most environmentally benign use, short of native prairie.

http://www.eatwild.com/benefits.html