A study focused on conventional dairy farming has found that calves can only develop a good relationship with humans if their caretakers have regular and gentle interactions like stroking lower part of their neck.
Calves are generally separated from their mothers on the day of their birth. They are then usually kept in single pens for a period of time before being housed in groups.
In the study involving 104 Holstein calves at a commercial dairy farm in Germany, first author Stephanie Lurzel and her colleagues from the Institute of Animal Husbandry and Animal Welfare at the Vetmeduni Vienna found that stroking the animals three minutes a day for 14 days after their birth improved the human-animal relationship.
The researchers examined the quality of the human-animal relationship using the so-called avoidance distance test, which measures the distance at which a calf avoids a person approaching it from the front.
Animals with less fear of humans show a lower avoidance distance. In animals that are afraid of people, the avoidance distance is higher.
The experiments showed that stroked calves do not avoid people as quickly as animals from the control group. The avoidance distance was lower among the stroked animals.
Stroked calves also gained weight more quickly.
About 90 days after their birth, stroked calves weighed more than the control group. The gentle contact with humans therefore appears to have a direct influence on the animals' weight gain.
"In earlier studies our team found out that cows especially enjoy being stroked at this spot. The animals' heart rates even fall during stroking," Lurzel said.
"A study from the year 2013 shows that cows that gained weight more quickly before weaning produce more milk. The daily weight gain of the stroked calves in our study was about 3 percent higher than that of the control group. This would translate into around 50 kg more milk per cow per year," Lurzel added.
The study was published recently in the journal Applied Animal Behaviour Science.
