Forsøksdyr: The effect of NSAIDS on the physiological and behavioural response to LPS in group-housed gilts

Godkjenningsdato 14.03.2018

The aims are to describe the effect of immune activation on brain physiology and social behavoiur in pigs and to test whether an NSAID will alleviate the sickness symptoms and the following changes in social dynamics. Lipopolysaccharide will be used to model a controlled, short-lived immune activation. We have experience with the strain and dose of LPS we apply for use of here. Within 6 hours, the immune parameters are back to baseline and the pigs resume their baseline behavioural time budget including eating.

Societal value: tail biting is a very important animal welfare challenge in commercial pig production.
The frequency is actually on the increase, also in Norway. The increase in the national average incidence of tail biting damage recorded at slaughterhouses has actually increased from about 2.5% to about 7% during the last 6 years. Most swine producing countries tail dock their pigs as an attempt to inhibit the behaviour. We know that health is a risk factor for tail biting, and this experiment is part of a larger body of work in which we try to understand the mechanisms behind the link between health and tail biting. By getting that understanding we might be able to better chose and evaluate methods to reduce the risk of tail biting outbreaks, such as a targeted use of NSAIDs (anti-inflammatory drugs with several licensed for use in pigs) in the case of disease outbreaks.

Scientific value: The immune system and the brain communicates, and we are starting to understand that immune activation can affect behaviour and emotions quite profoundly. This project will add knowledge of how brain and behaviour are influenced by a controlled immune activation.

We will apply for using 56 gilts in this experiment. They will be distributed on four different experimental groups and they will be euthanised by the end of the experiments. In addition, we will use 18 barrows as companion pigs. They will not be handled and will stay on the university farm until they are sold to a commercial farmer.

As this experiment is carried out mainly to increase our knowledge of tail biting in pigs, we cannot replace the pigs with non-animal models. The demands of a sufficient statistical power also prohibits the reduction of group sizes. However, we will refine the experiment by low-stress handling and sampling techniques and by keeping the pigs in stable social groups.