Near the Danish city of Ikast, some 1,500 spectators gathered on Apr. 19 to celebrate what has become something of a national holiday at organic dairy farms around Denmark. Courtesy of Organic Denmark hide caption

itoggle caption Courtesy of Organic Denmark

A cow walks away from an icy pond after firefighters rescued it and one other cow that had fallen through the ice. Darin Anstine/AP hide caption

itoggle caption Darin Anstine/AP

The Ingenues, an all-girl band and vaudeville act, serenade the cows in the University of Wisconsin, Madison's dairy barn in 1930. The show was apparently part of an experiment to see whether the soothing strains of music boosted the cows' milk production. Angus B. McVicar/Wisconsin Historical Society hide caption

itoggle caption Angus B. McVicar/Wisconsin Historical Society