Cows and their calves communicate using calls that are individualised in a similar way to human names, scientists have discovered.
Researchers found it was possible to identify particular cows and calves from the exclusive sounds they made.
The British team spent ten months studying the ways cows talked to their young.
They identified two distinct maternal calls: low sounds when a mother was close to her calf, and louder, higher pitched calls when they were out of visual contact.
Calves, in return, called out to their mothers when they wanted to start suckling.
But the most important finding was that all three calls were individualised - reserved for a particular cow and calf so that each recognised the other.
The team studied two herds of free-range cattle on a farm in Radcliffe-on-Trent, Nottinghamshire.
Recordings were made using highly sensitive equipment that gathered enough data to study for a year.
Further work may reveal vocal indicators of well-being or distress in cows, which could influence animal care policies, say the researchers, whose findings appear in the journal Applied Animal Behaviour Science.
Dr Alan McElligott at Queen Mary University of London said it is the first time that complex cattle calls have been analysed using the latest and best techniques.
He said: "Our results provide an excellent foundation for investigating vocal indicators of cattle welfare.
"By investigating vocalisations in behavioural contexts outside of mother-offspring communication, further research could reveal vocal indicators of welfare - and influence change in animal care policies."
