Hypothesis and Theory ARTICLE
A proposed role for pro-inflammatory cytokines in damaging behaviour in pigs
- 1Department of Paraclinical Sciences, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Norway
- 2School of Natural and Environmental Sciences, Newcastle University, United Kingdom
- 3Pig Development Department, Teagasc Animal and Grassland Research and Innovation Centre, Ireland
- 4Adaptation Physiology Group, Wageningen University and Research, Netherlands
- 5Department of Production Animal Clinical Sciences, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Norway
- 6National Institute for Research and Development for Biology and Animal Nutrition, Romania
- 7Agricultural Institute, Bulgaria
- 8Research Centre for Animal Welfare, Department of Production Animal Medicine, University of Helsinki, Finland
Sickness can change our mood for the worse, leaving us sad, lethargic, grumpy and less socially inclined. This mood change is part of a set of behavioural symptoms called sickness behaviour and has features in common with core symptoms of depression. Therefore, the physiological changes induced by immune activation, for example following infection, are in the spotlight for explaining mechanisms behind mental health challenges such as depression. While humans may take a day off and isolate themselves until they feel better, farm animals housed in groups have only limited possibilities for social withdrawal. We suggest that immune activation could be a major factor influencing social interactions in farm animals, with outbreaks of damaging behaviour such as tail biting as a possible result. The hypothesis presented here is that the effects of several known risk factors for tail biting are mediated by pro-inflammatory cytokines, proteins produced by the immune system, and their effect on neurotransmitter systems. We describe the background for and implications of this hypothesis.
Keywords: Cytokines, pig, Social Behavior, Tail biting, Health - clinical
Received: 20 May 2020;
Accepted: 10 Aug 2020.
Copyright: © 2020 Nordgreen, Edwards, Boyle, Bolhuis, Veit, Sayyari, Marin, Dimitrov, Janczak and Valros. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: PhD. Janicke Nordgreen, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Department of Paraclinical Sciences, Oslo, 0102, Oslo, Norway, email@example.com