Oink, oink: scientists decode pig emotions from their sounds

What does it mean when a pig oinks, shrieks or grunts?

The study suggests Orangutans use slang to show off their coolness.

Researchers from the University of Copenhagen, the French National Research Institute for Agriculture, Food and Environment, and the Swiss Federal Institute of Technology recorded 7,414 sounds from 411 pigs in different scenarios.

The pigs were then analysed to see if they were experiencing a positive or negative emotion.

The recordings were collected from situations encountered by commercial pigs. Behavior and heart rates were monitored by researchers.

Due to the impact of emotions on vocalization, the analysis of vocal expression of emotions is increasingly being considered as an important non-invasive tool to assess the affective aspects of animal welfare.

In the last decade, it has been shown that vocalizations of various animal species produced in specific emotional contexts and/or physiological states display specific acoustic characteristics.

Positive situations include when piglets suckle from their mothers. Separation, fights, castration and slaughter are negative situations.

The mock scenarios were designed to evoke more nuanced emotions. Such scenarios included an arena with toys or food, but without any stimuli. New and unfamiliar objects were introduced.

When pigs experience both positive and negative emotions, they vocalize high-frequency calls such as screams or shrieks, while low-frequency calls such as barks and grunts occur.

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

The calls are shorter in the positive situations. The grunts begin high and go lower in frequencies.

The calls can be categorized into 92% of them being the correct emotion.

Most modern animal welfare efforts focus on physical health.

Briefer said that they need someone who wants to develop an app that farmers can use to improve the welfare of their animals.