CHILTON, Wis. — Lucky, a 7-year-old dairy cow, had been walking with a limp for several weeks when veterinarian Sara Gilbertson was called. Instead of prescribing painkillers, Gilbertson tried an unusual new therapy — a chiropractic adjustment that included a full-length spinal massage.

Gilbertson rubbed the Holstein’s spine by gently squeezing it from neck to tail, pausing to apply firm pressure to one hip and readjust several vertebrae. The cow stood in calm silence, moving only enough to reach another mouthful of hay. Later, as Lucky reclined on a bed of sand, Gilbertson noted with satisfaction how relaxed and comfortable the animal seemed.

Cow comfort has become a key concern for the nation’s farmers, who have known for generations that contented cows give more milk. The traditional techniques for keeping cows happy aren’t complicated — feed them well, keep the temperature comfortable and give them room to move around. But some dairy farmers are turning to a new array of creative options intended to keep cows as mellow — and productive — as possible.

Some farmers have installed waterbeds for their 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, all part of the effort to ensure maximum milk output.

Do the methods really work? There’s no sound scientific data to back up the claims, but dairy farmers say they can see the difference with their own eyes — cows are giving more milk, the milk quality is improving and the herds seem to be enjoying the indulgences.

“It’s kind of like how an athlete with a sprained ankle isn’t as productive,” said Larry Meyer, 36, whose parents own the dairy farm in Chilton, Wis., where Lucky and another 115 dairy cows live. “If you can get a cow healthy and back to normal, it makes a difference in their productivity.”

Cows can suffer injuries if they slip on a slick spot of concrete or get stepped on by another 1,500-pound bovine, and some calves get their necks kinked during the birthing process. The injuries can cause pain when the animals stand, making them reluctant to jostle for food and leading to compensatory injuries. That, in turn, leads to less milk production.

That’s why farmers are willing to spend about $75 per session for a chiropractic adjustment.

“The cows tolerate it incredibly well,” said Gilbertson, the veterinarian. “They may be apprehensive at first, until they figure out how good it feels.”

Meyer didn’t have specific figures on how much milk Lucky gave following her chiropractic treatments, but because her mother was the most productive cow in the herd, he wanted to make sure Lucky was in good shape.

While chiropractic care is reserved for injured cows, dairy farmers also are investing in healthy cows’ happiness.

Richard Conrad installed $70,000 waterbeds on his farm in Grafton, Ohio, about a year ago. It took the 220 dairy cows a few months to adjust to the softer surface but now they seem to enjoy it, he said.

“They were real skeptical at first because it was real jiggly,” said Conrad, 53, “but once they adapted they didn’t look back. They just jump on and stay there.”

The result has been milk with fewer impurities and in greater volume — cows that used to give about 80 pounds of milk per day now average about 90 pounds, Conrad said. However, he couldn’t credit the waterbeds with all the improvement; he also upgraded ventilation in his barns and installed misting technology to keep the herd cool.

Dairy farmers commonly adjust air, temperature and lighting to keep cows happy. Some have also installed large rotating brushes that gently scratch the cows’ backs and massage their faces and shoulders, said Marcia Endres, a University of Minnesota Extension dairy scientist.

And some dairy producers have employed even more unusual techniques, even in absence of scientific data that justifies their use. In Germany, for example, the Dortmund Concert Hall plays recordings of different classical pieces for specific cows. The hall then serves milk from the respective cows during live concerts featuring those same pieces.

“Which means you’ll now be able to both listen to and taste the musical highlights,” the hall says in one advertisement.

Dairy experts agree the concept is entertaining, if a bit of a logical stretch. They also agree that dairy farmers need to be careful about introducing new techniques — music, waterbeds, chiropractic care — into a herd that’s already relatively comfortable.

“Cows are creatures of habit. They like things to stay the same,” Endres said. “So many producers like to not introduce too much change. Cows just don’t like a lot of weird things happening to them.”