Pig grunts have been decoded in a breakthrough which could help farmers monitor the emotional welfare of their droves and, in time, other animals too.
A team of international scientists made thousands of sound recordings from 400 pigs when they were involved in everyday activities such as nursing their young, huddling together or investigating an unusual object.
They then designed an algorithm to decode the noises and discovered that their sounds changed consistently depending on what was going on – with happy and excited pigs tending to make short confident noises, while scared or stressed pigs made longer and shakier sounds.
Running and being reunited with their mother produced the shortest most contented sounds, while physical restraint changed their cries to a long, rattling blare.
It's the first study in the world to translate the squeals and grunts of pigs into distinct emotions, and the researchers are hoping the algorithm can be turned into a programme which farmers can use to monitor the welfare of their pigs.
“We have trained the algorithm to decode pig grunts. Now, we need someone who wants to develop the algorithm into an app that farmers can use to improve the welfare of their animals,” says Dr Briefer, associate professor of the University of Copenhagen’s Department of Biology, who co-led the study.
There are already programmes which can remotely monitor the physical health of animals, but so far nothing has been created which can keep track of emotional changes.
The team believes that the system could be used to better understand the emotions of other mammals.
The research was published in the journal Scientific Reports.