Investigating the reward cycle of play in pigs (Sus scrofa)

Lidfors, Lena (author), Farhadi, Negar (author), Anderson, Claes (author), Zupan Šemrov, Manja (author)

Observations of play in animals have been suggested as a promising indicator of positive emotions and thus of positive animal welfare. However, if play can follow the proposed reward cycle concept where animals estimate and value reward differently in different phases of the cycle (anticipation, consummation and post-consummation) is unclear. To investigate if a reward cycle for play exists in growing pigs, we carried out an exploratory study where pigs were tested when they were naïve to a reward cycle test (first occasion) against when they were accustomed to going through the test after having the access to an open play arena with objects. Forty undocked pigs were housed in a weaner stable with two castrated males and two females per pen. Within each litter, we randomly selected and tested one male and one female test pig, each being tested as naïve or accustomed to the testing environment. The first week the pigs (n = 20) were tested four times and regarded as naïve during the first day. After that they were regarded as accustomed, and were tested twice a week for 3 weeks. We observed the behavior of the tested pairs in three subsequent stages: (1) in a holding pen 3 min, (2) in a play arena 15 min, and (3) in their home pen 10 min. When accustomed, pigs showed more locomotor play, social interactions and standing, and a tendency of more orientation toward the play arena and exploring bars facing the play arena (i.e., reward-seeking behavior) in the holding pen than when they were naïve, suggesting an anticipation to enter the play arena. Performing high numbers of object play in all sessions, and for accustomed pigs more exploration and social interaction, but less locomotor play and walking in the play arena may suggest consumption of play and exploration. Finding more lying and sitting in accustomed pigs, but less standing and walking in the home pen is in line with the previous hypothesis of the post-consummatory behaviors. Our study showed mixed results for the existence of a reward cycle for play in pigs and generated questions for future research.

• Language: English
• Keywords: fattening pigs, anticipation, consumption, relaxation, locomotor play, object play, social interactions, exploration
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty
• Publication status: Published
• Publication version: Version of Record
• Year: 2021
• Number of pages: Str. 1-14
• Numbering: Vol. 2, art. 740778
• PID: 20.500.12556/RUL-133695
• UDC: 636.4:591.5
• ISSN on article: 2673-6225
• DOI: 10.3389/fanim.2021.740778
• COBISS.SI-ID: 87419139
• Publication date in RUL: 09.12.2021

Record is a part of a journal

• Title: Frontiers in animal science
• Shortened title: Front. anim. sci.
• Publisher: Frontiers Media SA
• ISSN: 2673-6225
• COBISS.SI-ID: 34583299

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.
• Licensing start date: 18.11.2021

Secondary language

• Language: Slovenian
• Keywords: prašiči, pitanci, etologija, obnašanje živali, igra, dobrobit živali

Projects

• Funder: Other - Other funder or multiple funders
• Project number: Formas, Grant Number 221-2010-35