Behavioural lateralization in domestic pigs (Sus scrofa)—variations between motor functions and individuals

ABSTRACT

Motor lateralization is hypothesized to depend on the complexity of the motor function, but it might at the same time reflect hemispheric dominance within an individual across motor functions. We investigated possible motor lateralization patterns in four motor functions of different complexity (snout use in a manipulative task, foot use in two-stepping tasks and tail curling) in the domestic pig, a tetrapod species relevant as farm animal but also as a model in human neuroscience. A significant majority of our sample showed individual biases for manipulation with their snout and for curling their tail. Interestingly, the tail curling was lateralized towards the right at the population level and showed stronger lateralization patterns than the snout. Using a cluster analysis with combined tail and snout laterality, we identified groups of individuals with different lateralization patterns across motor functions that potentially reflect the individuals’ hemispheric dominance. To conclude, our results suggest that pigs show lateralization patterns that depend on the motor function and on the individual. Such individual lateralization patterns might have broader implications for animal personality and welfare. Our study lays the methodological groundwork for future research on laterality in pigs.

KEYWORDS:

• Task complexity
• motor lateralization
• foot
• snout
• tail curling

Acknowledgements

The authors would like to thank Evelin Normann, Heinz Deike, Katrin Siebert and Jenny Stracke for technical support in the execution of experiments and analysis of the data and Christian Nawroth for helpful comments on the manuscript. We would also like to thank the staff of the Experimental Facility for Pigs (EAS) of the Leibniz Institute for Farm Animal Biology for taking care of the animals and for all of their help during the execution of the experiments.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was supported by the Deutsche Forschungsgemeinschaft, DFG [grant numbers LE 3421/1-1 and DU 1526/1-1]. The publication of this article was partially funded by the Open Access Fund of the Leibniz Institute for Farm Animal Biology (FBN).