Updated

Dairy farmers have known for generations that contented cows give more milk. Now they're coming up with creative, new options to help keep their cows as happy as possible.

Some farmers are installing waterbeds for cows to rest on, while others play classical music. And some hire animal chiropractors to give older cows a tuneup and correct minor issues in calves. It's all part of the effort to ensure maximum milk output.

Do the methods work? There's no sound scientific data to back up the claims, but dairy farmers say they believe they're seeing improved productivity.

Veterinarian Sara Gilbertson recently did a chiropractic adjustment in Chilton, Wis., for a dairy cow that developed a limp. She says cows are only apprehensive about treatment until they discover how good it feels.