Liquid disinfectant drips from the teat of a dairy cow before milking at the Hunter Haven Farms dairy farm in Pearl City, Illinois, U.S., on Friday, March 30, 2012. Photographer: Daniel Acker/Bloomberg
Dairy cows are milked at the Hunter Haven Farms dairy farm in Pearl City, Illinois, U.S., on Friday, March 30, 2012. Photographer: Daniel Acker/Bloomberg