Individual play patterns stimulated by a familiar object are group-driven

Manja Zupan,Linda Keeling,Therese Rehn,Špela Malovrh,Daiana De Oliveira

doi:10.1038/s41598-019-42382-9

Manja Zupan, Linda Keeling + Show 3 more

Open Access

https://doi.org/10.1038/s41598-019-42382-9

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Abstract

This study investigates the dynamics of play behaviour within groups of four juvenile pigs and uses a novel clustering and statistical modelling approach to describe new details in how individuals play with a familiar object (toy rope). We examined complex state sequence data collected during a 30 min home pen play test, using the package TraMineR, where the states were defined as object play, locomotor/social play and no play. From behavioural observations, and based on the relative proportion of the different types of object play observed, each individual was later categorised as an initiator or joiner type of player. Initiators were found to be more solitary and to show more object play whereas joiners were more social and showed less object play. The majority of groups did not have an initiator type of player, yet on average they played more. Despite strong group and type of player effects, we identified three general individual play patterns. On a group level, our results demonstrate differences in how a period of playing develops, that playing with the object simultaneously occurs more often in groups than expected by chance and that the number of pigs playing together is stable over time.

Highlights

Animal welfare scientists agree that play is an important indicator of good animal welfare[1] and that promoting it may be a useful tool to improve housing conditions for captive animals such as chimpanzees[2] or commercial animals such as domestic pigs[3]
Pigs spent more than half of their time playing (56.6%) with most time being allocated to performing object play (ObjP; 49.2%; on the ground 39.0% and off the ground 10.2%)
The main finding of this study is that when given the opportunity to play with toys in a familiar environment for 30 min, play behaviour in pigs was group-driven despite the fact that each individual animal has its own specific pattern of play during this time

Summary

Introduction

Animal welfare scientists agree that play is an important indicator of good animal welfare[1] and that promoting it may be a useful tool to improve housing conditions for captive animals such as chimpanzees[2] or commercial animals such as domestic pigs[3]. Further it was emphasized that the complexity of social relationships was a crucial driver in the development of the primate brain[15] and that play contributes to the development of skills necessary to navigate social relationships as adults[16] This and other increasing evidence[17,18,19] for the adaptive benefits of play illustrate the function of social play, which is to promote complex socio-cognitive development (e.g., play-mediated learning) and behavioural flexibility. There are many details of how animals in groups play that are not yet described Improved understanding of these details could contribute to our understanding of the evolutionary significance of mammalian play and, perhaps, open up new avenues of how to stimulate play behaviour in commercial pigs. We hypothesized that individual play patterns are affected by group dynamics

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