How scientists learned how to accurately decode pigs’ emotions

By Joe Morgan via SWNS

The "language'"of pigs has been decoded after scientists went through recordings of more than 7,000 pig grunts to decipher the animals' emotions.

It is hoped it can be turned into an app so that farmers and pet owners can decipher how their pig really feels such as whether they are happy, excited, scared or stressed.

Using the audio recordings, researchers designed an algorithm that can decode the emotions of a pig from birth until death.

Pigs are highly intelligent animals, with complex emotions, and are on par with dogs.

The researchers recorded pig sounds in both standard and experimental scenarios, such as being reunited with family, piglets suckling from mothers, fights between piglets, and playing with toys.

These included an arena with toys or food and a corresponding arena without any stimuli.

The researchers also placed new and unfamiliar objects in the arena for the pigs to interact with.

Along the way, the pigs' calls, behavior and heart rates were monitored and recorded when possible.

Short grunts signified happiness, which was recorded such as when they were freely running or nursing, while lots of vocalizations showed they were scared or upset, such as when they recorded waiting in the slaughterhouse.

Typical signs of negative emotions in pigs are that they stand still, emit a lot of vocalizations, and try to escape, while positive ones include exploring their surroundings and having their ears postured forward.

The algorithm, based on a total of 7414 sounds from 411 pigs, was able to classify 92 percent of the calls to the correct emotion.

The international team of researchers now hope app developers take an interest and build something for farmers to use to keep track of their livestock.

Dr. Elodie Briefer, associate professor at the University of Copenhagen, said: "With this study, we demonstrate that animal sounds provide great insight into their emotions.

"We also prove that an algorithm can be used to decode and understand the emotions of pigs, which is an important step towards improved animal welfare for livestock.

"There are clear differences in pig calls when we look at positive and negative situations.

"In the positive situations, the calls are far shorter, with minor fluctuations in amplitude.

"Grunts, more specifically, begin high and gradually go lower in frequency. By training an algorithm to recognize these sounds, we can classify 92% of the calls to the correct emotion."

The findings from 16 researchers from Denmark, Switzerland, France, Germany, Norway, and the Czech Republic were published in the journal Scientific Reports.