Feeding behaviour: The missing link between pig welfare and pig nutrition research

Summary

Domesticated pigs in a natural environment spend more than 50% of their active time with foraging, exploring and feeding. The expression of this behavioural complex is very species-specific and pigs are highly motivated to display it. The inability to do so may result in damaging behaviour such as tail biting. While feeding behaviour is central for the pigs’ welfare, it has been neglected both in animal welfare as well as in animal nutrition research. These two disciplines differ in the used methodology, their understanding of welfare and also the part of the behavioural complex of feeding they are dealing with. In animal welfare research the appetitive part is in the focus. The appetitive part includes foraging, rooting and exploring. Animal welfare researchers investigate enrichment materials such as straw or artifical tools that are supposed to satisfy the behavioural needs of pigs in this respect. The actual interaction with the provided feed itself and the suitability of the feed to satisfy behavioural needs is usually not targeted in this field. Studies originating from the animal nutrition discipline, on the other hand, deal with the very last part of the behavioural complex, the consummatory part. The focus here is on nutrient and energy intake, and thus performance, efficiency and health. The approach is based on a concept of animals that prioritizes physiological and anatomical functions over emotional or behavioural aspects. The missing overlap between these two disciplines has had consequences for the developments that have been achieved in these fields but also for the advances in animal welfare in general. Feed composition, processing and presentation in commercial pig feeding are usually optimized for efficiency and health purposes but not to meet behavioural, species-specific needs.
Integrating the pigs behavioural ecology into considerations how to improve pig feeding has thus great potential to advance pig welfare in commercial settings. During the conference presentation we will provide evidence for the missing link and show options how to increase the overlap.