Pigs express their emotions through grunts, study reveals

Mohsina Dodhiya8th March 20228th March 2022News, Vegan Activism

“The study demonstrates that animal sounds provide great insight into their emotions.”

In a first of its kind research, scientists have decoded a way to translate pig grunts into actual emotions across an extended number of conditions and life stages.

With the help of artificial intelligence, an international team of researchers has developed a pig translator, which turns oinks, snuffles, grunts and squeals into emotions.

The 16-member research team from Denmark, Switzerland, France, Germany, Norway and the Czech Republic has been led by the University of Copenhagen, the ETH Zurich and France’s National Research Institute for Agriculture, Food and Environment (INRAE).

The findings have been published in the journal Scientific Reports in which the team states that the translator can be developed into an app that can help farmers to automatically monitor animal well being and pave the way for better livestock treatment.

Study

Researchers designed an algorithm to interpret whether an individual pig is ‘happy’ or ‘excited’ (positive emotion), or ‘scared’ or ‘stressed’ (negative emotion) or somewhere in between.

The algorithm was applied to around 7,414 pig calls recorded from more than 400 animals.

The recordings were collected across a spectrum of conditions encountered by commercial pigs from when they are born until their deaths.

While most of the recordings came from farms and other commercial settings, others came from experimental set ups where pigs were given toys, food and other objects to explore.

The developed algorithm helped distinguish the noises into positive and negative emotions.

Researchers found that positive situations such as huddling with littermates, suckling their mothers, running about and being reunited with the family elicited characteristic noises while negative circumstances ranging from piglet fights, crushing, castration and waiting in the abattoir gave rise to specific calls.

For instance, high-pitched squeals and screams were prominent in negative situations.

Low-pitched grunts and barks were heard across the board, regardless of their situation but a short grunt was generally an indication of the animal’s contentment.

‘Important step towards improved animal welfare’

Dr Elodie Briefer, an animal communication expert and co-lead of the research 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.”

According to Briefer, the algorithm correctly classified 92% of the calls as positive or negative emotions. Interestingly, the recordings also exhibited a pattern that revealed what the pigs experienced in certain situations in great detail.

“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,” she said.

Although, the study of animal emotions is relatively new – with the interest peaking in the last 20 years – it is widely accepted that the mental health of livestock is important for their overall well-being.

Yet, today’s animal welfare focuses primarily on the physical health of livestock and several mechanisms are already in place to automatically assess an animal’s physical health for a farmer.

The researchers hope this algorithm will pave the way for a new platform for farmers to monitor their animals’ psychological well-being.

Moreover, with enough data to train the algorithm, the method could also be used to better understand the emotions of other mammals.

“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,” Briefer concluded.