Both laying hens and pigs show damaging behaviour towards conspecifics, e.g. feather pecking and tail biting. These forms of damaging behaviour are remarkably similar in both species and are in both cases related to frustration of normal exploratory behaviour.
Keep in mind that in the wild, both pigs and chickens are highly explorative omnivores, a trait which seems to have been conserved through decades of domestication. What is also striking is the relationship between damaging behaviour and health. When we select for animals that show less damaging, we also see changes in the immune system and related stress physiology. In laying hens, we have also seen that we can trigger feather pecking by challenging the immune system.
Recently, we have started to investigate the role of the microbiota-gut-brain axis in damaging behaviour, as evidence is increasing that the composition of the microbiota of laying hens and pigs plays a key-role in shaping their behaviour. These research approaches yield important scientific knowledge, but also potentially have a large impact in commercial practice.
In 2018, beak trimming of laying hens will be prohibited in The Netherlands and discussions on prohibiting tail docking are ongoing. Both procedures were introduced to prevent damage and mortality in group-housed animals. Therefore, real solutions to reduce damaging behaviour through adaptations in breeding, housing or management are needed by the livestock industry.
Speakers: Bas Rodenburg and Inonge Reimert