Evaluation of a scheme to identify risks for tail biting in pigs.

BackgroundTail biting is a common and serious welfare problem in pig production, causing large economical losses. Tail docking is performed routinely in most EU countries to reduce the tail biting risk. However, tail docking is painful, and does not prevent tail biting totally. The risk factors behind tail docking are multifactorial and most analyses are based on studies using biological or epidemiological approaches. There is very little information available on how producers deal with tail biting on-farm. There are also no studies on the attitude of producers towards tail docking and tail biting in systems with long-tailed pigs. We aimed to study how farmers rate the efficiency of different measures for preventing and intervening with tail biting, when tail docking is not allowed. Furthermore, we investigated the attitudes of Finnish farmers to tail docking and tail biting.ResultsRespondents scored feeding-related issues to be most important for prevention of tail biting, identifying and removing the biting pig as most important intervention measures, and straw as the most important manipulable material when preventing tail biting. Tail biting was not perceived as a very serious problem by over 70 % of the respondents, even though docking is not allowed, and was reported to occur close to a level which was also considered acceptable by the respondents. Most respondents did not think it is probable they would raise tail docked pigs if it were possible, but about 21 % probably would.ConclusionsIn comparison with other authors’ findings, the ranking of importance of risk factors for tail biting differs between scientists and farmers, and between farmers in different cultures of pig production. In addition, the attitude towards tail biting and tail docking appears to be very different in producers with different experiences of tail docking. These results indicate that a scientist-farmer dialogue, as well as international communication is important when trying to reduce the risk of tail biting, and subsequently the need for tail docking.

Decision support system with semantic model to assess the risk of tail biting in pigs1. Modelling

Tail biting (TB) is a major health and welfare challenge in commercial pig production. Diet is one of the six major risk factors proposed by the European commission (Commission, 2016). Research during the last decade has revealed a complex, bidirectional communication between gut microbiota, intestinal health and the brain, affecting mood and behaviour via the so-called microbiota-gut-brain axis (MGBA). This axis is affected by various factors of which diet plays a major role and thus may provide insight in the complex aetiology of TB. Individual differences in the balance of the MGBA may explain why certain risk factors lead to TB in some farms/pens but not in others. This review aims to connect the current research on the MGBA with known and proposed dietary risk factors for TB. The links are still largely unproven but can provide basis for future studies aiming for dietary interventions to mitigate TB. This review suggests that diet-related risk factors for TB are under- and oversupply of protein (incl. tryptophan), lack of satiation, fine feed particle size, low dietary fibre content and a limited number of feeder spaces. We hypothesise that these factors can cause social stress, gastric ulcers, dysbiosis of the gut microbiota, disruption of the intestinal epithelium and affect the animal’s stress sensitivity via the MGBA, which might cumulatively lead to TB. Major suggested pathways are via gut microbial metabolites inducing cytokine-induced sickness behaviour (i.e. immune activation) or shifting of the tryptophan-serotonin metabolism (associated with anxiety and depression). We further hypothesise that adequate amino acid levels incl. tryptophan and the inclusion of certain dietary fibres in the diet exceeding levels in standard diets, may stimulate establishment of a beneficial gut microbiota (e.g. microbial diversity and short-chain fatty acid producing bacteria) that protect against inflammation and increase stress resilience. While treatment with antibiotics is a useful tool to combat the presence of potential specific bacteria that pose a risk of TB, it can at the same time disturb the gut microbial balance, which in turn increases the risk of TB. In conclusion, while TB is multifactorial, we suggest that an imbalance in the MGBA, modulated via the diet, should be considered as a pathway for the development of TB, but needs more research. We suggest a whole-animal approach, including considerations on gut health, satiety, a beneficial gut microbiota and an adequate feed supply avoiding social stress to mitigate TB.

Tail biting in pigs is a widespread problem in intensive pig farming. The tendency to develop this damaging behaviour has been suggested to relate to serotonergic functioning and personality characteristics of pigs. We investigated whether tail biting in pigs can be associated with blood serotonin and with their behavioural and physiological responses to novelty. Pigs (n = 480) were born in conventional farrowing pens and after weaning at four weeks of age they were either housed barren (B) or in straw-enriched (E) pens. Individual pigs were exposed to a back test and novel environment test before weaning, and after weaning to a novel object (i.e. bucket) test in an unfamiliar arena. A Principal Component Analysis on behaviours during the tests and salivary cortisol (novel object test only) revealed five factors for both housing systems, labeled ‘Early life exploration’, ‘Near bucket’, ‘Cortisol’, ‘Vocalizations & standing alert’, and ‘Back test activity’. Blood samples were taken at 8, 9 and 22 weeks of age to determine blood platelet serotonin. In different phases of life, pigs were classified as tail biter/non-tail biter based on tail biting behaviour, and as victim/non-victim based on tail wounds. A combination of both classifications resulted in four pig types: biters, victims, biter/victims, and neutrals. Generally, only in phases of life during which pigs were classified as tail biters, they seemed to have lower blood platelet serotonin storage and higher blood platelet uptake velocities. Victims also seemed to have lower blood serotonin storage. Additionally, in B housing, tail biters seemed to consistently have lower scores of the factor ‘Near bucket’, possibly indicating a higher fearfulness in tail biters. Further research is needed to elucidate the nature of the relationship between peripheral 5-HT, fearfulness and tail biting, and to develop successful strategies and interventions to prevent and reduce tail biting.

Most of the piglets get their tails docked during the first days of living in order to prevent or at least minimize the occurrence of tail biting in pigs. This routine practice of docking is not in accordance with the provisions of the EU and the German Animal Protection Act. Furthermore, the underlying causes of tail injuries are not eliminated by docking the tails. If tail biting occurs, an animal welfare problem will often result, combined with economical disadvantages for the pig farmer. Consequently solutions are needed in order to abdicate the routine tail docking of piglets quickly. In the present study potential reasons of tail biting of pigs should be narrowed and solutions in accordance with animal welfare should be invented for use in practice in order to escape from tail docking step by step. On the basis of the present study it gets obvious that even though possible preventative measures are used, the occurrence of tail biting of pigs can never be fully eliminated. Therefore an intensive and aware observation of the pigs by the farmer seems to be necessary to recognize an incipient occurrence of tail biting and to act appropriate. It remains to be said that keeping undocked pigs represents a challenging task, nevertheless a step-by-step abdication of the routine docking of the pig tails seems possible.

BackgroundEuropean legislation dictates that pig tail docking is not allowed to be performed routinely (European Union. Council Directive 2008/120/EC of 18 December 2008 laying down minimum standards for the protection of pigs. OJ L 47, 18.2.2009). Nevertheless, tail docking is still practiced routinely in many European countries, while four countries stopped routine tail docking completely. Tail docking is also practiced in many countries outside Europe.The Federation of Veterinarians of Europe (FVE), the European Association of Porcine Health Management (EAPHM) together with the European Commission carried out an online survey to investigate the situation regarding the practice of pig tail docking and the provision of enrichment material across 24 European countries. It also focuses on the role of the veterinary profession and gives an overview on published literature regarding the challenges and possibilities related to the raising of pigs with intact tails.ResultsFifty-seven (57) usable survey responses from 24 countries were received. On average 77% (median = 95%) of pigs are routinely tail-docked. In Finland, Norway, Sweden, Switzerland, less than 5% of the pigs are tail-docked. According to the respondents, 67% of pigs (median = 76%) across the 24 EU countries surveyed are given suitable enrichment materials. Training of veterinary practitioners, their role in advising the producer and undertaking a risk assessment of tail biting were more positively valued in countries that stopped routine tail docking than in countries that had not stopped routine tail docking. Initiatives such as training from national authorities to encourage abandoning tail docking and routine recording of tail biting at the slaughterhouse were identified as two successful items to promote the raising of pigs with entire tails.ConclusionIn many European countries the majority of the pigs are still routinely tail-docked, which is a violation of the European legislation. To stop routine tail docking it is necessary to raise the awareness and education about risk factors to prevent tail biting. The growing knowledge about the reasons for failing voluntary national initiatives as well as about successful measures taken by some countries to make pig production with intact tails feasible should be distributed throughout the EU pig producing community. The veterinary profession has a significant role to play in raising awareness, facilitate knowledge transfer and to identify risk factors and solutions on farm level for the benefit of pig health and welfare.

BackgroundTail biting is a common problem in intensive pig farming, affecting both welfare and production. Although routine tail docking is banned within the EU, it remains a common practice to prevent tail biting. Straw as environmental enrichment has been proposed as an alternative to tail docking, but its effectiveness against tail biting and function in manure handling systems have to be considered. The aim of the study was to survey how pigs with intact tails are raised and how tail biting is handled in Sweden, where tail docking is banned through national legislation. The study emphasises straw usage and its association with tail biting pigs and problems in the manure handling system. The expectation is that this information could be conveyed to the rest of the EU to reduce the need for tail docking.ResultsIn a telephone survey of randomly selected Swedish pig farmers (46 nursery and 43 finishing pig units) with at least 50 sows or 300 finishing places, it was found that straw was used by 98% of the farmers. The median daily straw ration provided was 29 g/pig for nursery and 50 g/pig for finishing pigs in systems with partly slatted flooring. The reported prevalence of tail biting was 1.6% at slaughter. The majority of farmers reported that they never had manure handling problems caused by straw (56% of nursery units and 81% of finishing pig units). A proportion of farmers (37%) also provided with additional material apart from straw on some occasions, which may have affected tail biting prevalence and manure handling problems.ConclusionsSwedish farmers rear undocked pigs without large problems with tail biting. Straw is the main manipulable material used, and additional manipulable material is used to various extents. The low incidence of straw obstructing the manure handling systems implies that it is indeed possible to use straw in partly slatted flooring systems, reducing the need for tail docking. The impact of using additional manipulable material is unknown and requires more investigation to separate the impact of such material from the impact of straw.Electronic supplementary materialThe online version of this article (doi:10.1186/s13028-016-0266-8) contains supplementary material, which is available to authorized users.

Research on low‐protein diets in pig production has focused on improving protein retention efficiency and reducing nitrogen waste. However, these diets have been shown to increase the risk of damaging behaviours like tail biting—a major welfare and performance issue in commercial farms. Current strategies to reduce tail biting include preventive measures such as tail docking and management approaches like environmental enrichment. Since tail docking is already banned by the EU as a routine practice, new non-invasive measures need to be investigated and integrated with existing ones in a multifactorial approach.In Chapter 2, an experiment conducted on a commercial farm examined the effects of amino acid (AA) supplementation and environmental enrichment on pigs fed an AA-deficient low-protein diet. Pigs on this diet exhibited lower growth performance, increased activity compared to pigs fed a normal protein or AA-supplemented diet, and increased tail biting. Although extra environmental enrichment initially reduced tail biting, its effectiveness diminished over time, even though it consistently reduced ear biting. In contrast, supplementation of AA to meet the requirements for maximal growth reduced tail biting compared to the AA-deficient low-protein diet. This confirms that AA deficiency contributes to damaging behaviours, and AA supplementation counteracts these effects more effectively than enrichment.Further studies explored the ability of pigs to self-supplement AA under standard conditions or conditions known to increase AA requirements. In Chapter 3, pigs given the choice between two and four diets achieved the same feed intake and body weight gain as animals provided with an AA-adequate diet. When offered a supplemented diet containing a combination of three AA at higher concentrations, pigs proportionally decreased consumption of the supplemented diet. However, when given a choice among individually AA-supplemented diets, pigs proportionally decreased consumption of a diet with high valine concentration, showed no aversion for a diet with high threonine concentration, and exhibited a strong preference for a diet with high tryptophan concentration. The resulting AA intake differed from that required for maximal body weight gain, indicating that pigs might choose AA to prioritize other physiological processes over growth.In Chapters 4 and 5, a second choice-feeding experiment investigated whether the self-supplementation of AA to compensate for an AA-deficient diet differed for piglets kept under different sanitary conditions. Low sanitary conditions negatively affected piglets’ growth, immune status, and neurotransmitter levels. Contrary to expectations, piglets increased their preference for an AA-supplemented diet over time under high sanitary conditions but not under low sanitary conditions. Furthermore, low sanitary conditions led to reductions in plasma and brain tryptophan concentrations, platelet serotonin, neurotransmitter concentrations in the hippocampus and prefrontal cortex, and play behaviour compared to piglets under high sanitary conditions. Although offering dietary choices slightly reduced aggressive behaviours, sanitary conditions had a stronger influence on piglet welfare than diet alone.Overall, these findings support a necessary shift in the conception of the ideal AA profile, from a static model determined by the human objective of maximising growth, to a more dynamic pig-centred approach that accommodates variable requirements for diverse functions and priorities.

Tail biting in pigs Hunter, E. J., Jones, T. A., Guise, H. J., Penny, R. H. C. & Hoste, S. (2001) The relationship between tail biting in pigs, docking procedure...

Tail Biting in Pigs

The long and short of it: A review of tail docking in farm animals

Tail biting is a major welfare and economic problem for indoor pig producers worldwide. Low tail posture is an early warning sign which could reduce tail biting unpredictability. Taking a precision livestock farming approach, we used Time-of-flight 3D cameras, processing data with machine vision algorithms, to automate the measurement of pig tail posture. Validation of the 3D algorithm found an accuracy of 73.9% at detecting low vs. not low tails (Sensitivity 88.4%, Specificity 66.8%). Twenty-three groups of 29 pigs per group were reared with intact (not docked) tails under typical commercial conditions over 8 batches. 15 groups had tail biting outbreaks, following which enrichment was added to pens and biters and/or victims were removed and treated. 3D data from outbreak groups showed the proportion of low tail detections increased pre-outbreak and declined post-outbreak. Pre-outbreak, the increase in low tails occurred at an increasing rate over time, and the proportion of low tails was higher one week pre-outbreak (-1) than 2 weeks pre-outbreak (-2). Within each batch, an outbreak and a non-outbreak control group were identified. Outbreak groups had more 3D low tail detections in weeks -1, +1 and +2 than their matched controls. Comparing 3D tail posture and tail injury scoring data, a greater proportion of low tails was associated with more injured pigs. Low tails might indicate more than just tail biting as tail posture varied between groups and over time and the proportion of low tails increased when pigs were moved to a new pen. Our findings demonstrate the potential for a 3D machine vision system to automate tail posture detection and provide early warning of tail biting on farm.

Tail biting is a common issue within commercial pig production. It is mainly an indicator of inadequate housing environment and results in reduced health welfare and production. To reduce the impact of tail biting, pigs are commonly tail docked, without pain relief, within the first week of life. EU Council Directive 2008/120/EC prohibits routine tail docking, but the practice is still widely used in many Member States. Sweden has banned tail docking since 1988 and all pigs have intact tails, yet tail biting is a minor problem. This paper summarises and synthesises experimental findings and practical expertise in production of undocked pigs in Sweden and describes solutions to facilitate a transition to producing pigs with intact tails within intensive pig production in the EU. Swedish pig housing conditions and management differ in many aspects from those in other EU Member States. Swedish experiences show that lower stocking density, provision of sufficient feeding space, no fully slatted flooring, strict maximum levels for noxious gases and regular provision of litter material are crucial for success when rearing pigs with intact tails. To prevent tail biting and to eliminate the need for tail docking, we strongly recommend that EU legislation should more clearly match the biological needs of pigs, as is done in Swedish legislation.

Effect of pen design on tail biting and tail-directed behaviour of finishing pigs with intact tails

Which is the most preventive measure against tail damage in finisher pigs: tail docking, straw provision or lowered stocking density?