Dairy cows eat in a barn at the Hunter Haven Farms dairy farm in Pearl City, Illinois, U.S., on Friday, March 30, 2012. Photographer: Daniel Acker/Bloomberg
Dairy cows stand in a barn at the Hunter Haven Farms dairy farm in Pearl City, Illinois, U.S., on Friday, March 30, 2012. Photographer: Daniel Acker/Bloomberg
Dairy cows stand in a containment area as they wait to be milked at the Hunter Haven Farms dairy farm in Pearl City, Illinois, U.S., on Friday, March 30, 2012. Photographer: Daniel Acker/Bloomberg