Will Bessie make more milk if you call her by name? British ag specialists say she will.

Dairy farmers who address their cows by name reported 68-gallon (258-liter) higher milk yields over the animals’ 10-month lactation period than those who didn't, according to new research published today in Anthrozoos, a British journal dedicated to the "interactions of animals and people."

British researchers compared production from the country's National Milk Records with the survey responses of 516 dairy farmers to see if there was an association between yield and cow naming. Dairy farmers who reported calling their cows by name got 2,105 gallons (7,938 liters) out of their cows, compared with 2,029 gallons (7,680 liters) per 10-month lactation cycle. The results held regardless of the size of the farm or how much the cows were fed. (Some 46 percent of the farmers named their cows.)

"It was quite a revelation and quite encouraging, actually," says study co-author Catherine Douglas of Newcastle University in northeast England and a former dairy industry advisor. She tells ScientificAmerican.com the reason for the link is unclear, but speculates it may have a soothing effect on cows, which tend to fear people and get nervous when led into the milking parlor.

"If cows are slightly fearful of humans, they could produce [the hormone] cortisol, which suppresses milk production," Douglas says. Farmers who have named their cows, she adds, "probably have a better relationship with them. They're less fearful, more relaxed and less stressed, so that could have an effect on milk yield."

But Marcia Endres, an associate professor of dairy science at the University of Minnesota, wasn't impressed.  "Individual care is important and could make a difference in health and productivity," Endres says. "But I would not necessarily say that just giving cows a name would be a foolproof indicator of better care."

Named or otherwise, cows make six times more milk today than they did in the 1990s, according to a 2007 piece in The Scientist. One reason is growth hormone that many U.S. farmers now inject their cows with to increase their milk output; another is milking practices that extend farther into cows' pregnancies, according to the article. Selective breeding also makes for lots of lactation.

Douglas notes that England doesn’t allow dairy cows to be fed hormones. The European Union and Canada have banned the use of recombinant bovine growth hormone (rGBH), which increases cases of an infection called mastitis that requires the animals to be treated with antibiotics, some of which can make their way into our refrigerators. rGBH-treated cows also have elevated levels of the hormone insulin-like growth factor 1 (IGF1), according to the Center for Food Safety, which may be associated with cancer in humans.

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