Doctoral student Krista McLennan of Britain’s Northampton University, who discovered the relationships, says that if these bonds were recognized and honored within dairies, it could improve milk yields.

During her research, cattle were penned on their own, with their best friend or with another cow they did not know for 30 minutes while their heart rates were measured at 15-second intervals.

Cortisol levels were also measured to determine how well the cows cope when isolated.

“When heifers have their preferred partner with them, their stress levels in terms of their heart rates are reduced compared with if they were with a random individual,” McLennan told reporters.

She also pointed out that modern farming practices often force cows to be separated for visits from the vet or as portions of the herds are moved around.

“We know re-grouping cows is a problem, because there’s a high level of stress among animals as they try to integrate into a new group,” McLennan said.

Photo: Dale Kimberling