Know more

About cookies

What is a "cookie"?

A "cookie" is a piece of information, usually small and identified by a name, which may be sent to your browser by a website you are visiting. Your web browser will store it for a period of time, and send it back to the web server each time you log on again.

Different types of cookies are placed on the sites:

  • Cookies strictly necessary for the proper functioning of the site
  • Cookies deposited by third party sites to improve the interactivity of the site, to collect statistics

Learn more about cookies and how they work

The different types of cookies used on this site

Cookies strictly necessary for the site to function

These cookies allow the main services of the site to function optimally. You can technically block them using your browser settings but your experience on the site may be degraded.

Furthermore, you have the possibility of opposing the use of audience measurement tracers strictly necessary for the functioning and current administration of the website in the cookie management window accessible via the link located in the footer of the site.

Technical cookies

Name of the cookie


Shelf life

CAS and PHP session cookies

Login credentials, session security



Saving your cookie consent choices

12 months

Audience measurement cookies (AT Internet)

Name of the cookie


Shelf life


Trace the visitor's route in order to establish visit statistics.

13 months


Store the anonymous ID of the visitor who starts the first time he visits the site

13 months


Identify the numbers (unique identifiers of a site) seen by the visitor and store the visitor's identifiers.

13 months

About the AT Internet audience measurement tool :

AT Internet's audience measurement tool Analytics is deployed on this site in order to obtain information on visitors' navigation and to improve its use.

The French data protection authority (CNIL) has granted an exemption to AT Internet's Web Analytics cookie. This tool is thus exempt from the collection of the Internet user's consent with regard to the deposit of analytics cookies. However, you can refuse the deposit of these cookies via the cookie management panel.

Good to know:

  • The data collected are not cross-checked with other processing operations
  • The deposited cookie is only used to produce anonymous statistics
  • The cookie does not allow the user's navigation on other sites to be tracked.

Third party cookies to improve the interactivity of the site

This site relies on certain services provided by third parties which allow :

  • to offer interactive content;
  • improve usability and facilitate the sharing of content on social networks;
  • view videos and animated presentations directly on our website;
  • protect form entries from robots;
  • monitor the performance of the site.

These third parties will collect and use your browsing data for their own purposes.

How to accept or reject cookies

When you start browsing an eZpublish site, the appearance of the "cookies" banner allows you to accept or refuse all the cookies we use. This banner will be displayed as long as you have not made a choice, even if you are browsing on another page of the site.

You can change your choices at any time by clicking on the "Cookie Management" link.

You can manage these cookies in your browser. Here are the procedures to follow: Firefox; Chrome; Explorer; Safari; Opera

For more information about the cookies we use, you can contact INRAE's Data Protection Officer by email at or by post at :


24, chemin de Borde Rouge -Auzeville - CS52627 31326 Castanet Tolosan cedex - France

Last update: May 2021

Menu Logo Principal Institut Agro Rennes-Angers

Home page

What piglets tell us

2020.12.17 - What piglets tell us
Toward a better understanding of the links between vocal expression and emotional states in pigs

We have investigated the vocalisation structure (frequency, duration and energy repartition) and its relationship with emotional states in pigs, especially through the human-animal relationship. These studies were part of a European Eranet project called Soundwel and have given encouraging results, as they may allow the development of automated software to monitor animal welfare using real time recording of vocalisations in farms.

Pigs are social animals and communicate using a large variety of call types (Tallet et al, 2020). Since 2016, Peagase UMR have coordinated the European project called Soundwel, aiming at better understanding of the links between vocal expression and emotional states. The acoustic structure of vocalisations depends on the perception of the environment by the animal, and especially their perception of humans. One part of the project was to use vocalisation structure to better understand the perception that piglets had of a human.

Vocal expression and emotional state

In the first study, we compared vocal responses to conspecifics (pen mates) or humans (one familiar human, providing additional positive contacts to the piglets), after piglets were trained to anticipate both types of partner. Piglets produced grunts at a higher rate when anticipating the arrival of their pen mates than when anticipating ‘their human’. Grunts were noisier (spectral noise) when piglets expected to meet with their conspecifics, whereas they were longer and higher pitched when they expected to meet with the human. These characteristics indicate a positive perception of the anticipation of conspecifics and a state close to frustration before meeting with the human. This study demonstrates for the first time that vocal expression of anticipation in piglets is specific to the type of expected event. In addition, tamed piglets have a different vocal expression from non-tamed piglets, suggesting a long term effect of the human-animal relationship on vocal communication.


Figure 1 : Vocal expression of anticipation of conspecifics or a familiar human. A: Experimental set up and room. B: Procedure of the conditioning. Piglets learnt to anticipate the arrival of two conspecifics or a familiar human, during twelve repeats per (pseudo)social partner. An audio visual stimulus announced the entrance of the partner. The duration of the visual stimulus was progressively increased to generate an anticipation phase. For the last trial, the entrance of the partner was delayed to trigger frustration. After acoustic analysis of grunts, we can see the effect of the anticipation and frustration on (C) the duration of grunts and (D) their spectral composition.

Vocalisation structure and perception of enrichments and humans

In a second study, after a two week familiarization of piglets with both a human, providing additional positive contacts, and an object, known as enrichment, we tested the impact of a reunion with each of the stimuli after a social isolation (known to be stressful).
Vocal expression showed that the human triggered a positive state (shorter grunts than during isolation), indicating reassurance for piglets, whereas the object did not.
Piglets’ emotional state and their proximity to conspecifics and humans is reflected in the structure of their vocalisations, especially their grunts (duration, spectral noise and frequency band), revealing the mental representation that piglets build toward humans.


Figure 2 : Effect of a post isolation reunion with an object, a familiar human or nothing on (A) behaviour of piglets, (C) duration of grunts produced during the test and (B) their spectral composition.
These results provide a useful acoustic basis for the development of automated software to classify and detect emotions in pigs’ vocalisations.

Further reading

  • Céline Tallet, Lisette M C Leliveld, E.F. Briefer. Vocalizations. Pigs welfare in practice, 5M Publishing, pp.56, 2020, Animal Welfare in Practice, 978-1-7891-8-1050. ⟨
  • Avelyne Villain, Azélie Hazard, Margot Danglot, Carole Guérin, Alain Boissy, et al.. Piglets vocally express the anticipation of pseudo-social contexts in their grunts. Scientific Reports, Nature Publishing Group, 2020, 10 (1), pp.18496. ⟨10.1038/s41598-020-75378-x⟩. ⟨
  • Avelyne Villain, Mathilde Lanthony, Carole Guérin, Céline Tallet. Manipulable object and human contact: preference and modulation of emotional states in weaned pigs. Frontiers in Veterinary Science, Frontiers Media, 2020, 7, ⟨10.3389/fvets.2020.577433⟩. ⟨
  • Data available on Data Inrae :