At any given time, a pig farm in southwestern Ontario sniffs around 12,500 Duroc hogs around the barnyards of Emani Farms.
The farm pen is a cocofony of trembling, screaming, bark and grunts, in which each voice telegraphs a different feeling or need. According to Stuart Skinner, 38, co-owner of the farm, pigs are expressive animals with a wide range of sounds. Interpreting their calls can occasionally stump even experienced farmers.
“I’ve often joked that this job would be a lot easier if we could talk pigs,” Mr. Said Skinner.
Decoding the emotions behind those onyx may soon become a little easier. Researchers in Europe have developed an algorithm that evaluates the emotional state of pigs based on animal sounds.
“Animal welfare today is widely accepted to be based not only on the physical health of animals, but also on their mental health,” said Elody Briffer, an associate professor of biology at the University of Copenhagen and author of the study published this week. Journal Scientific Reports. The sooner a farmer can discern whether an animal is happy or sad, the sooner any problems in the animal’s environment that may affect its health can be resolved.
Pigs are more sensitive to domestic animals, producing a wider range of noises than relatively obscure goats, sheep and cows. To crack the Pig communication code, scientists at five research laboratories across Europe used a hand-held microphone to receive approximately 7,400 different calls from 411 individual pigs. Calls were recorded during the pig’s lifetime, from birth to slaughter.
The researchers then assigned a positive or negative emotional value to each sound based on what the paper calls an “intuitive guess”. In other words, the researchers made an educated guess as to how the pig would have felt about the event at which the sound was recorded (i.e. feeding, good; castration, bad).
After the first hearing, most people do a little better than the chance to guess his feelings based on the pig’s voice. Listen closely enough to pig calls, though, and the pattern emerges.
The grunts associated with positive emotions – the sounds that pigs make when they are separated from their mothers or littermates when feeding, running or rejoining – are short, and have a one-note consistency in tone.
Surprisingly, an unhappy pig looks horrible. Crisis-causing situations include maternal vag (common risk for piglets), slaughter, hunger, fights, and the unwelcome surprise of strange people or objects in their pens, inadvertently being crushed. The screaming, screaming, and barking of animals experiencing fear or pain are both longer and more changeable in tone than sounds of satisfaction.
When taught to listen to these simple differences, humans do a much better job of accurately interpreting the emotional state of the animal, Drs. Briefer said. But artificial intelligence did its best. The researchers’ algorithm, designed by co-author Sierra Seiford, correctly identified animal emotions 92 percent of the time as positive or negative.
The study is the product of Soundwell, a project sponsored by the European Union to improve the health and well-being of animals. Researchers with the project are now considering partnering with an engineer who can incorporate their data into an app or other tool that farmers can use to interpret their animals’ calls and emotional states in real time. Briefer said.
Understanding the feelings of animals has practical and legal consequences. Animal law laws, such as the current British Parliament, emphasize that animals are capable of thought and emotion, and that their welfare should be taken into account when formulating policies that may affect the government. The European Union recognized animal emotions in 2009.
Mr. Said Skinner.
“The ability to identify problems as early as possible is one of the most important factors in the success of treatment,” said Mr. Said Skinner. “Any tool that is adaptable to the pantry settings that will enhance the understanding of what individual animals experience will be valuable.”