Researchers interviewed 516 farmers.
Happy cows produce more milk, according to researchers at Newcastle University.
Cattle that are named and treated with a "more personal touch" can increase milk yields by up to 500 pints a year.
The study, by the university's School of Agriculture, Food and Rural Development, involved 516 farmers across the UK.
Published in the journal Anthrozoos, the study found farmers who named their cows gained a higher yield than the 54% that did not give their cattle names.
Dairy farmer Dennis Gibb, who co-owns Eachwick Red House Farm outside Newcastle with his brother Richard, said he believed treating every cow as an individual was "vitally important".
"They aren't just our livelihood, they're part of the family," he said.
"We love our cows here at Eachwick and every one of them has a name.
"Collectively we refer to them as 'our ladies' but we know every one of them and each one has her own personality."
Dr Catherine Douglas, who led the research, said: "What our study shows is what many good, caring farmers have long since believed.
"Our data suggests that, on the whole, UK dairy farmers regard their cows as intelligent beings capable of experiencing a range of emotions.
"Placing more importance on knowing the individual animals and calling them by name can, at no extra cost to the farmer, also significantly increase milk production."