Commercial pigs are frequently exposed to tail mutilations in the form of preventive husbandry procedures (tail docking) or as a result of abnormal behaviour (tail biting). Although tissue and nerve injuries are well-described causes of pain hypersensitivity in humans and in rodent animal models, there is no information on the changes in local pain sensitivity induced by tail injuries in pigs. To determine the temporal profile of sensitisation, pigs were exposed to surgical tail resections and mechanical nociceptive thresholds (MNT) were measured in the acute (one week post-operatively) and in the long-term (either eight or sixteen weeks post-surgery) phase of recovery. The influence of the degree of amputation on MNTs was also evaluated by comparing three different tail-resection treatments (intact, ‘short tail’, ‘long tail’). A significant reduction in MNTs one week following surgery suggests the occurrence of acute sensitisation. Long-term hypersensitivity was also observed in tail-resected pigs at either two or four months following surgery. Tail amputation in pigs appears to evoke acute and sustained changes in peripheral mechanical sensitivity, which resemble features of neuropathic pain reported in humans and other species and provides new information on implications for the welfare of animals subjected to this type of injury.
“This guide aims to give practical advice to pig farmers surrounding the complex
issue of providing suitable environmental enrichment to pigs. It provides
useful information from the knowledge of farmers, researchers and scientific
literature on the different ways environmental enrichment can be provided for
differing types of housing and systems. The information is set out in sections
by housing type, and in each, the types of enrichments that are most suited
to each system are discussed, including their properties, how to present
the enrichment, quantities and practical considerations, such as ease of
installation, maintenance and costs.” (cited from the introduction in the guide).
The Tail Biting “WebHAT” (Web based Husbandry Advisory Tool) is a website designed to be an interactive resource providing information about the key risks for tail biting in pigs and practical suggestions to help reduce these risks on-farm.
Taking information from evidence-based sources and scientific literature, this WebHAT identifies a number of risks associated with tail biting (a key pig behaviour), and can be used to generate a report of prioritised, key tail-biting risks found on a farm and obtain suggestions to address the specific risks identified
Despite a long history of debate about negative affective states in animals, it was only in the last decades of the 20th century that the state of pain was mentioned in definitions of animal welfare, included in veterinary education, and became a target of scientific interest. Pain is a perceptional phenomenon built from information gathered by specialized sensory receptors for tissue damage and integrated into a discrete experience with a negative emotional valence in the brain. Based on knowledge about porcine neuroanatomy, physiology, and studies focusing on pig behavior and pathology, we review evidence for causes of pain in pigs, underlying biological mechanisms, as well as the possibility to quantify different types of indicators of pain states relevant to the welfare of the animals under production conditions. The presentation will primarily focus on pigs because of the dual purpose of this species as a meat producing as well as research animal species (the latter driven by the anatomical and physiological homologies with humans), making pigs unique among livestock. We will present methodologies and results from current research projects across Europe and North America targeting typical industry-related injuries (e.g., tail docking, lameness, and shoulder lesions) and aiming to understand the welfare consequences for the pigs. Throughout the talk, the emphasis will be put on future opportunities to link research outcomes with industry initiatives toward the improvement of animal welfare and production. In addition, possible future research efforts to help face current methodological limitations and favor a more comprehensive evaluation of animal pain as an overall experience will be discussed. This seeks to facilitate common future targeted research and enable us to overcome the paradoxical low level of knowledge about porcine pain and its alleviation under production conditions.
Tail biting constitutes a major welfare and health issue in commercial pig rearing, with significant negative economic consequences. Contrary to the aim of the EU directive (2001/93/EC), tail docking is still widely practiced in most EU countries as a measure to reduce the incidence of tail biting and concomitant pathologies. Mutilations are a general welfare concern in all species, and any efforts towards reducing the need for tail docking are important for the future sustainability of the EU pig sector. Sound policy making needs science-based risk assessment, including assessment of the severity of problems and effectiveness of solutions. The general objectives of the FareWellDock-project included estimation of the relative harms associated with tail docking and tail biting, and evaluation of the efficacy of some main preventive measures against tail biting, which could reduce the need for tail docking. The ultimate aim was to stimulate the development towards a non-docking policy in the EU.
The first objective of WP1 was to evaluate measures of acute and chronic pain in relation to tail damage. This included assessment of the short (acute trauma), medium (post trauma inflammation) and long term (traumatic neuroma formation) pain associated with tail docking in neonatal piglets, and the possible consequences for longer term fear of humans. In addition, the studies assessed the effects of tail-damage in more mature pigs to provide a basis for assessing the pain associated with being tail bitten in later life. Finally, studies were conducted to assess the effects of an NSAID analgesic on the short term responses to neonatal tail docking.
Experimental studies confirmed that piglets do experience pain when tail docked, and that pain relief treatment, such as meloxicam, can lessen but not abolish the physiological stress reaction to docking. Piglets which have been tail docked seem more fearful of people afterwards than undocked animals. In docked tails, no difference in pain sensitivity of the tail (as measured by behavioural withdrawal) is detected after 8 weeks, but changes in the functioning of the sensory nerves from the tail can still be measured after 4 months, which suggests that the possibility for longer term pain exists. When the tail is damaged later in life, as happens with tail biting, changes in both tail stump sensitivity and nerve functioning can last for at least 4 months, and possibly beyond.
WP2 focused on the role of manipulable material when reducing the need for tail docking. The aim was to develop and validate ways to assess if on-farm use of manipulable material is sufficient to reduce tail biting. Further, the aim was to describe suitable methods for implementing the use of straw under commercial farming conditions and to investigate, in on-farm conditions, the efficiency of tail docking vs. enrichment given in sufficient quantity to reduce the occurrence of tail lesions.
A screening method to assess the appropriateness of the level of enrichment on-farm was developed and includes scoring of the amount of unsoiled straw, the behaviour, and ear, tail and flank lesions of the pigs. AMI (animal-material interaction) sensors were used e.g. to show that pigs in biter pens were more interested in novel ropes than pigs in control pens, that environmental enrichment may reduce exploratory behaviour of point-source objects, and that sick pigs, experimentally infected with streptococcus spp, were less interested in chain manipulation. The sensors appear to be a promising tool to assess the use of manipulable material by pigs. In countries (SE and FI) where tail docking is not done, farmers report using on average of 30 to 50 g of straw/pig/ day, equivalent to about 0.5 L/pig/day. A survey in SE revealed fewer injurious tail biting outbreaks on farms using larger amounts of straw. Larger amounts of straw were mainly used on farms having scrapers in the slurry channels. A large experimental study showed that a moderate amount of straw (150 gr/pig/day) reduced injurious tail-biting outbreak in finisher pigs by more than 50%, while docking seemed to be more effective as it reduced tail biting by more than four-fold. The effect of both measures was additive, i.e. docking and straw reduced tail biting 9 fold. Further, it was shown that increasing the amount of straw from 10 to up to 400 gr/pig/day had multiple positive effects by progressively reducing the occurrence of tail injuries and stomach ulcers, increasing growth rate, increasing straw-directed behaviour, and reducing redirected behaviours towards other pigs.
In WP3 the aim was to clarify the role of poor health in the causation of tail biting and victimization, and the aim was study early identification of tail-biting outbreaks. In addition, the aim to develop automated systems for early warning of tail biting outbreaks.
The results of experimental and on-farm studies showed that the social behaviour of sick pigs differs from healthy pen mates, as pigs with osteochondrosis received more sniffing and tail bites from their pen mates than healthy pigs, while pigs with mild respiratory disease tended to bite more at the ears and tails of pen mates than healthy pigs did. In addition, studies of cytokines suggest that low-grade inflammation may decrease activity and increase receiving sniffs and attacks from other pigs. Studies on data sets from commercial pig farms indicated that changes in feeding behaviour may be an important sign of an increased risk for tail biting to occur: Future tail bitten individuals showed a reduced feed intake already 2-3 weeks before tail damage became evident. Furthermore, feeding behaviour in groups which develop tail biting may differ from non-biting groups for at least ten weeks prior to an injurious tail-biting outbreak. It was also shown that tail-chewing activity may start 2-3 weeks before tail damage can be seen. A detailed behavioural study of tail biting events revealed that there appears to be no such thing as a ‘typical’ tail-biting event and that the behaviour shown immediately before a tail-biting event does not differ from behaviour prior to another type of social interaction, namely ano-genital sniffing. Thus, it seems difficult to predict if a social event will escalate into tail biting or not. However, tail biting is more likely between pigs that have previously interacted. Data sets from several countries and studies indicated an association between tail-biting damage and tear staining, but the direction of this association is not clear.
In summary the project concluded on a set of practical recommendations, which have been published as part of four factsheets on the FareWellDock-webpage:
Avoid tail docking whenever possible because it definitely causes pain, induces long-term changes in sensory-nerve function and may impair the pigs’ confidence in humans.
Avoid tail biting, and hence the need for tail docking, by addressing risk factors on the farm.
Treat tail-bitten pigs promptly and consider pain relief.
To reduce injurious tail-biting outbreaks, use straw as it might be almost as effective as tail docking. For this purpose, the more straw the better.
To ensure that sufficient straw is allocated check that there is left-over straw before the next day’s allocation.
Keep your pigs healthy. This will be good both for productivity and also help avoid injurious tail-biting outbreaks.
If pigs show signs of illness, be more alert to tail biting risk.
Remove tail-bitten pigs promptly to avoid further damage and treat according to veterinary advice.
Pay special attention to groups of pigs where you see:
high or suddenly increased levels of general activity or exploration
tail manipulation or chewing
swinging or tucked tails
low or decreasing numbers of visits to an automatic feeder or reduced feed intake
Information on project activities and publications have been continuously published on the FareWellDock-webpage. To date, 16 scientific articles have been published, and 9 are in preparation. Communication to stakeholders has been active, both through the FareWellDock-webpage, including 97 blog posts, and by interviews in media in different countries, popular articles and presentations at producer seminars. In October 2016 the results were presented widely at the EU level to policy makers and other stakeholders at the ‘Meeting and Webinar on Actions to Prevent Tail biting and Reduce Tail docking of Pigs’, organized by the European Commission Directorate General for Health and Food Safety in Grange, Ireland.
Due to the positive experience of the cooperation a decision was made at the last project meeting in DK in October 2016 that we will continue our cooperation as the FareWellDock-network, also inviting further researchers and stakeholders to join. The first activity of the FWD-network will be to organise a satellite meeting at the Congress of the International Society for Applied Ethology in August 2017 in DK, and to launch an emailing list to make sure FWD-network members and other researchers keep updated on research progress and related topics.
The FareWellDock factsheets are out. Below you find the cover factsheet as well as the factsheets on tail docking, enrichment, health and the prediction of tail biting. This post shows images of the English versions, and links to the pdf version of the English factsheets, as well as all factsheets in Danish, Dutch, Finnish, French, Italian, Norwegian and Swedish. Separate pages are available directly showing the factsheets in the other languages (Danish, Dutch, Finnish, French, Italian, Norwegian and Swedish).
A recent research paper has reported a positive effect of an online training tool on participants’ understanding of taildocking and enrichment legislation, as well as risk factors for tail biting. The training tool was aimed at official inspectors and others involved in enforcement of legislative requirements on pig farms. The research was a collaboration of 15 researchers from 9 EU countries, led by the University of Bristol, UK. The online training tool is free to use and is available in 7 different languages: English, French, German, Polish, Italian, Spanish and Dutch. It can be accessed here:
An online training package providing a concise synthesis of the scientific data underpinning EU legislation on enrichment and taildocking of pigs was produced in seven languages, with the aim of improving consistency of professional judgements regarding legislation compliance on farms. In total, 158 participants who were official inspectors, certification scheme assessors and advisors from 16 EU countries completed an initial test and an online training package. Control group participants completed a second identical test before, and Training group participants after, viewing the training. In Section 1 of the test participants rated the importance of modifying environmental enrichment defined in nine scenarios from 1 (not important) to 10 (very important). Training significantly increased participants’ overall perception of the need for change. Participants then rated nine risk factors for tail-biting from 1 (no risk) to 10 (high risk). After training scores were better correlated with risk rankings already described by scientists. Scenarios relating to tail-docking and management were then described. Training significantly increased the proportion of respondents correctly identifying that a farm without tail lesions should stop tail-docking. Finally, participants rated the importance of modifying enrichment in three further scenarios. Training increased ratings in all three. The pattern of results indicated that participants’ roles influenced scores but overall the training improved: i) recognition of enrichments that, by virtue of their type or use by pigs, may be insufficient to achieve legislation compliance; ii) knowledge on risk factors for tail-biting; and iii) recognition of when routine tail-docking was occurring.
Note that the training tool is being used in Poland to train animal science students, farm assurance in the UK has shown recent interest in using the tool, and the Austrian pig health service is compiling a brochure based on EUWelNet on tail biting/enrichment material.
“Freedom from pain, injury and disease” is one of the fundamental aspects of good animal welfare. However, in commercial pig production there are a number of situations where animals may experience pain. This may result from procedures carried out deliberately for management purposes, or from spontaneous health disorders. In order to make decisions on the ethical justification of procedures and the provision of pain alleviation by appropriate anaesthesia and analgesia, it is necessary to assess the intensity and duration of pain experienced by the animals. A number of behavioural, physiological and molecular methods now exist for such assessment but, since pain is a subjective experience which the individual may express in different ways, interpreting these measures can be a challenge. Better methods are required for the practical on-farm assessment of pain and the provision of analgesia when this occurs.
Introduction: Concerns exist over the long term consequences for tail stump pain experienced by piglets after docking, especially in relation to traumatic neuroma development in caudal nerves after docking injury. Neuroma formation may cause detrimental sensory changes in the tail due to altered axonal excitability leading to abnormal sensation or pain.
Aims: To characterize pig tail histopathology at time intervals up to 16 weeks after tail docking and to measure expression of key neuropeptides in caudal dorsal root ganglia and spinal cord neurons associated with (i) peripheral nerve regeneration; activating transcription factor-3 (ATF3), (ii) inflammatory pain; Calcitonin gene-related peptide (CGRP) and (iii) the maintenance of chronic pain; N-methyl D-aspartate (NMDA) ionotropic glutamate receptor subtype 2B (GRIN2B) at the same time points after tail docking injury.
Materials and Methods: Thirty-two female piglets (Landrace/Large White x synthetic sireline) were used (16 docked/16 sham-docked). Piglets were tail docked (amputation of approx. 2/3 of the tail) on post-natal day 3 using a gas hot docking iron. Equivalent sham-docked piglets served as intact controls. Pigs were euthanized by barbiturate overdose 1, 4, 8 and 16 weeks after sham/tail docking. Tail stumps (2 cm) were collected post-mortem for histopathological assessment. Caudal dorsal root ganglia (Ca1-Ca4+) and associated spinal cord were collected for gene expression analysis by real-time quantitative PCR of mRNA.
Results: Non-specific epidermal and dermal changes associated with healing were observed after tail docking. Mild inflammation, ulceration and oedema were present at 1 week. Traumatic neuroma development was a consistent feature from 4 weeks after tail docking. Neuroma axonal dispersion in the tail stump was on-going 16 weeks after tail docking. ATF-3 mRNA was significantly upregulated in caudal DRGs up to 8 weeks after tail docking, but did not differ at 16 weeks compared with sham controls. Both CGRP and GRIN2B mRNA expression was significantly upregulated 1 week after tail docking in caudal spinal cord neurons but were not significantly different from sham-docked pigs thereafter.
Conclusion: Histopathological lesions that occur shortly after tail docking (beyond 1 week) are not likely to induce or maintain pain. The effects of tail docking on peripheral nerve axonal proliferation and dispersion are relatively short-lived and, although still present, are attenuated by 16 weeks after tail docking injury. Changes in peripheral and spinal nociceptive processing associated with possible inflammatory and chronic pain appear to resolve by 4 weeks after tail docking injury.