ERA NET ANIHWA FareWellDock: Ending tail docking and tail biting in the EU - a pig welfare problem

The catheter experiment (Nordgreen et al 2017c) showed that a low dose of LPS caused an increase in the classical pro-inflammatory cytokines (TNF-alfa, IL-6 and IL-1beta) during the first two to three hours post inject. This happened alongside a marked increase in cortisol. Following this, IL-12 increased and this cytokine stimulated white blood cells (NK-cells) that produce the cytokine IFN-gamma. This latter cytokine was found in increased levels in frontal cortex of LPS-injected pigs at 72 hours after injection. Interestingly, IFN-gamma is known to stimulate an enzyme that metabolises tryptophan to kynurenine. The result is that there is an increase in molecules that can stimulate glutamatergic signalling while less tryptophan is made available for serotonin production. This finding is the basis of a new internally funded PhD project starting in the end of 2017. Another interesting and unexpected finding in the brain samples was a markedly lower concentration of the neurotransmitter noradrenaline in the frontal cortex, hippocampus and hypothalamus of the LPS pigs compared to the controls 72 hours after LPS injection. The consequences of this are not clear, but it is possible that these pigs will be at risk to develop a depression-like condition as noradrenaline is regarded as protective against depression which may induce aberrant behaviour, targeting these pigs as potential victims. This finding will also be looked into further in the above-mentioned new project. In the social experiment (Munsterhjelm et al 2017d) we housed pigs in triplets and injected one per triplet with LPS and the others with saline. In the period 73-80 hours after injection (i.e. the same period in which the catheter pigs had shown a decrease in noradrenaline levels in the brain) the control pigs directed more social activity towards the LPS than the control pigs, and the LPS pigs tended to be less active. In addition to this the LPS-treated pigs were observed to direct more behaviour towards the ears and tails of penmates during the second day after LPS injection. Thus, when we combine the results from the catheterized pigs and the socially housed pigs, it seems that LPS induces behavioural changes that outlast the overt symptoms of illness and that coincides with changes in brain cytokine and neurotransmitter levels, and that might change the social dynamics in a small group of pigs. In most of the literature, LPS injected pigs are kept for a maximum of 12 hours. This cutoff means that longer-lasting changes are missed and also that one is only able to measure effects mediated by the innate immune system, as the adaptive immune system takes longer to become activated. One of the novel things in the current project is that we followed the pigs for 72 hours, allowing us to detect an increase in white blood cells (indicating that the adaptive part of the immune system became activated) and also changes in neurotransmitter levels and behaviour. In the field experiment (Munsterhjelm/Nordgreen et al 2017a), we compared social behaviour and cytokine-levels in pigs from several categories. These included healthy controls with low osteochondrosis scores from computer tomography (CT) scanning, pigs diagnosed with respiratory disease, pigs diagnosed with osteochondrosis based on clinical signs and pigs with high osteochondrosis scores from CT scans. The level of cytokines did not differ between the groups. There were, however, correlations between IL-12 (a pro-inflammatory cytokine) and IL1-ra (an anti-inflammatory cytokine), and several categories of behaviour. IL-12 correlated positively with inactive sitting, with receiving attacks in the pen and with receiving sniffs towards the body and tail at the feeder. IL1-ra correlated positively with sitting, with sniffing and biting the tails of other pigs, and with receiving tail sniffs at the feeder. In both the field experiment and the experiment in which the pigs were fitted with catheters and housed individually, we have measured the levels of 13 cytokines in the blood. To our knowledge, this is the first time data on this many cytokines have been published for pigs. The project thus contributes to general knowledge about the immune response of the pigs and the level of the different cytokines in young gilts and intact boars. In the questionnaire (Kallio et al 2017b) we collected data on feeding, diet, housing and management for 78 Finnish farms that did not practice tail amputation to compare farms with or without a history of tail biting. Slatted floors, increasing number of animals at the farm, the absence of bedding material, liquid feeding and larger group size were associated with an increased risk of tail biting outbreaks. This project has formed the basis for new projects COST Action GroupHouseNet http://www.grouphousenet.eu/ (2016-2020), with Andrew M Janczak at NMBU as prosject leader, as well as an NMBU-funded PhD project (2017-2020) lead by Janicke Nordgreen.

Tail biting is a major health and welfare hazard in the EU pig industry, and efficient tools to control the problem are lacking. Contrary to the aim of EU directive (2001/93/EC), tail docking is widely used in most countries. This proposal focuses on the interface between animal health and welfare, the development of animal-based indicators, the assessment of pain and suffering, and the improvement of management practices. The aims are to support quantitative risk assessment and a shift towards a non-do cking policy and practice. Tail docking is painful, and should be avoided, but tail biting is undesirable as well. Tail docking decreases the tail biting prevalence but it does not solve the underlying welfare problems, and a move towards adapting the env ironment to the pigs instead of vice versa is ethically justified. A more detailed hazard characterization is needed of the relative harms associated with tail docking and tail biting, as is further exposure assessment of the risks of tail biting, esp. in undocked pigs. We will provide this information and examine the efficiency of preventive measures to reduce the need for tail docking. Even though tail biting has a multifactorial background, this project focuses on the three most important related welf are hazards, namely tail docking, inadequate enrichment and poor health. The project includes studies on short- and long-term effects of tail docking and tail biting on pig welfare (WP1), tail biting and enrichment (WP2) and identification of individual a nd group characteristics predisposing pigs to tail biting, which can aid management of undocked animals (WP3). In this way the project aims to provide the scientific basis needed to reduce tail docking and tail biting, and thereby significantly improve pi g welfare in the EU.