Researchers say a major new study that found cows can communicate their feelings through their moos could have implications for farmers and animal welfare.
The research at the University of Sydney has shown that cows maintain individual voices in a variety of emotional situations and 'talk' to one another through their lowing, or moos.
Studying a herd of 18 Holstein-Friesian heifers over five months, PhD student Alexandra Green determined that the cows gave individual voice cues in a variety of positive and negative situations.
This helped them maintain contact with the herd and express excitement, arousal, engagement or distress, the research found.
The study, published in Scientific Reports, recorded 333 samples of cow vocalisations and analysed them using acoustic analyses programmes with assistance from colleagues in France and Italy.
The study concluded that farmers should use knowledge of individual cow voices in their daily farming practices.
"We found that cattle vocal individuality is relatively stable across different emotionally loaded farming contexts," said Green.
Positive contexts were during oestrus and anticipation of feeding.
Negative contexts were when cows were denied feed access and during physical and visual isolation from the rest of the herd.
Green said that by understanding these vocal characteristics, farmers would be able to recognise individual animals in the herd that might require individual attention.
"We hope that through gaining knowledge of these vocalisations, farmers will be able to tune into the emotional state of their cattle, improving animal welfare," she said.
It was previously known that cattle mothers and offspring could communicate by maintaining individuality in their lowing, however the new research confirms that cows maintain this individual voicing through their lives and across a herd.
"Ali's research is truly inspired. It is like she is building a Google translate for cows," said Associate Professor Cameron Clark, Green's academic supervisor.
"Cows are gregarious, social animals. In one sense it isn't surprising they assert their individual identity throughout their life and not just during mother-calf imprinting.
"But this is the first time we have been able to analyse voice to have conclusive evidence of this trait," said Green
Green travelled to Saint-Etienne, France, to work with some of the best bioacousticians in the world, including co-authors Professor David Reby and Dr Livio Favaro, to analyse the vocal traits of the cattle.
The study will be incorporated into her doctorate, which investigates cattle vocal communication and use in welfare assessment on dairy farms.