Study: Cows Grow Bigger, Give More Milk After Early Positive Human Interaction


A recent Austrian study has shown that stroking a calf on its neck during the first two weeks of its life has a positive impact on future growth and milk production. Rich LaSalle/Image Bank/Getty Images
A recent Austrian study has shown that stroking a calf on its neck during the first two weeks of its life has a positive impact on future growth and milk production. Rich LaSalle/Image Bank/Getty Images

Nineteen Holstein calves push their noses over waist-high fences around individual pens. They're milling about in a red barn the width of a soccer field. It is dinnertime, they're hungry, and they have just spotted their favorite person — a farmer pulling a green wagon loaded with bottles of warm milk.

He lifts the bottles and feeds each in turn, coaxing shy calves and hedging strong ones. As their tails whip and bellies fill, the farmer rubs their necks and backs, affectionately scratching behind an ear or two. 

A stereo plays classical music in the background, though its mellow tunes are temporarily eclipsed by the ruckus of the meal. In its place, the farmer offers a soothing monologue that settles over the calves' black and white coats.

"When you feed a calf a bottle of milk, and when you rub him on his neck or on his back, it makes him feel so much better," says Dean Patterson, loading empty bottles back onto his wagon and returning them to the milking parlor, which is housed in another barn. There, he'll wash the bottles and leave them prepped for the evening feeding, but will continue to check on the calves throughout the day.

Patterson, a 78-year-old fourth generation farmer, is building relationships with these calves in the same way he's done for a lifetime. At Patterson Family Farms, as at most conventional dairies, calves are separated from their mothers within a day or two of birth, then housed individually and in age-related groups where rely on people for sustenance and affection.

Developing Trust

This connection between calf and caretaker has been at the center of a research project by the Institute of Animal Husbandry and Animal Welfare at Vetmeduni Vienna, a university of veterinary medicine in Austria.

Stephanie Lurzel and her colleagues studied 104 Holstein-Friesian calves at a commercial dairy farm in Germany. From birth to Day 14, they stroked the necks of half the calves for three minutes a day and did not pet the other half of the group. By Day 90, the calves who had experienced neck rubs weighed more than the control group, pointing to the positive influence of gentle human interaction on animal weight gain.

Austrian researchers stroked some calves while ignoring others to study the effects on the human-animal relationship.
Austrian researchers stroked some calves while ignoring others to study the effects on the human-animal relationship.
Marc Decker

"The daily weight gain of the stroked calves in our study was about 3 percent higher than that of the control group," Lurzel said in a university press release.

Researchers also observed the quality of relationships between calves and caretakers through an avoidance distance test. The test, which measures the distance at which a calf will avoid a person who approaches it head on, revealed the stroked calves had a lower avoidance distance than the calves in the control group. In short, the calves who had been given special attention early on in their lives were less fearful and more welcoming when approached by people.

Good Moods, Good Milk

While these results may seem elementary to people who have worked with animals, studying the emotional impact of humans on animals in commercial production is an emerging field that could have a far-reaching impact on the animals' environments.

Previous studies have shown that when heifers gain weight more quickly, they go on to produce more milk. For the calves in the Vetmeduni Vienna study, their 3 percent weight gain could translate into 50 kilograms (110 pounds) more milk per cow per year, says Lurzel.

And in 2001, a pair of psychologists at England's University of Leicester demonstrated that playing soothing music to dairy cows increased their milk production. Strategies like this aren't new to the Patterson dairy, where classical music is played for cows and calves around the clock, says Deanna Lanier, who earned a bachelor's degree in animal science production management before returning to Patterson Family Farms to work alongside her grandfather, Dean Patterson, and her father and brother.

"There are a lot of things you can do to make cows more comfortable and show them you care for them. In turn, they will grow better, produce more milk and give higher quality milk," says Lanier, who chronicles farm life at The Milkmaid Times. "The more you care for them, the more you get out of that relationship."