Category Archives: Tail docking

Tail posture as an indicator of tail biting in undocked pigs

Tail posture as an indicator of tail biting in undocked finishing pigs

By Torun Wallgren, Anne Larsen and Stefan Gunnarsson, 2019. Animals. Special Issue Environmental Enrichment of Pigs.

Simple Summary

Tail biting is a large welfare problem in modern pig production, causing pain and reduced health and production. The identification of tail biting is important for minimising the risk of the escalation of the behaviour and its consequences. Tail posture (i.e., tail hanging or curled) has been suggested to depend on the presence of tail wounds and, therefore, has been suggested as an indicator of tail biting. This study investigated the relationship between tail position and tail damages at feeding, since that could be a feasible time for producers to detect tail posture. The experiment showed that 94% of the pigs had curly tails and that pigs with wounds were more likely to have hanging tails than pigs with nondamaged tails. By observing the tail position at feeding, we were able to identify pigs with tail wounds in 68% of cases simply by scoring pigs with hanging tails. To conclude, the scoring of pigs with hanging tails at feeding was found to be a useful tool for identifying tail damages, which may otherwise be difficult to detect by the caretaker.


Tail posture (i.e., hanging or curled) has been suggested to be an indicator of tail biting, and hanging tails predisposed to damage. The aim of this study was to investigate if tail posture was feasible as a tail damage indicator in a commercial setting. The study was carried out on one batch of 459 undocked finishing pigs (30–120 kg in weight). Weekly scoring of tail posture was combined with the scoring of tail lesions. Tail posture was observed at feeding to facilitate the usage of the method in commercial settings. A curly tail was observed in 94% of the observations. Pigs with tails scored with “wound” were 4.15 (p < 0.0001) times more likely to have hanging tails, and pigs scored with “inflamed wounds” were 14.24 (p < 0.0001) times more likely to have hanging tails, compared to pigs with nondamaged tails. Tail posture correctly classified tails with “wound” or “inflamed wound” 67.5% of the time, with 55.2% sensitivity and 79.7% specificity, respectively. The method of observing the tail position at feeding seems useful as a complement to normal inspection for detecting tail biting before tail wounds are visible to the caretaker.

How to control injurious tail biting without tail docking of pigs

Injurious tail biting in pigs: How can it be controlled in existing systems without tail docking. By D’Eath RB, Arnott G, Turner SP, Jensen T, Lahrmann HP, Busch ME, Niemi JK, Lawrence AB, Sandøe P, 2014. Animal 8:1479-97.

Abstract Tail biting is a serious animal welfare and economic problem in pig production. Tail docking, which reduces but does not eliminate tail biting, remains widespread. However, in the EU tail docking may not be used routinely, and some ‘alternative’ forms of pig production and certain countries do not allow tail docking at all. Against this background, using a novel approach focusing on research where tail injuries were quantified, we review the measures that can be used to control tail biting in pigs without tail docking. Using this strict criterion, there was good evidence that manipulable substrates and feeder space affect damaging tail biting. Only epidemiological evidence was available for effects of temperature and season, and the effect of stocking density was unclear. Studies suggest that group size has little effect, and the effects of nutrition, disease and breed require further investigation. The review identifies a number of knowledge gaps and promising avenues for future research into prevention and mitigation. We illustrate the diversity of hypotheses concerning how different proposed risk factors might increase tail biting through their effect on each other or on the proposed underlying processes of tail biting. A quantitative comparison of the efficacy of different methods of provision of manipulable materials, and a review of current practices in countries and assurance schemes where tail docking is banned, both suggest that daily provision of small quantities of destructible, manipulable natural materials can be of considerable benefit. Further comparative research is needed into materials, such as ropes, which are compatible with slatted floors. Also, materials which double as fuel for anaerobic digesters could be utilised. As well as optimising housing and management to reduce risk, it is important to detect and treat tail biting as soon as it occurs. Early warning signs before the first bloody tails appear, such as pigs holding their tails tucked under, could in future be automatically detected using precision livestock farming methods enabling earlier reaction and prevention of tail damage. However, there is a lack of scientific studies on how best to respond to outbreaks: the effectiveness of, for example, removing biters and/or bitten pigs, increasing enrichment, or applying substances to tails should be investigated. Finally, some breeding companies are exploring options for reducing the genetic propensity to tail bite. If these various approaches to reduce tail biting are implemented we propose that the need for tail docking will be reduced.

3D cameras can detect lowered tail posture before an outbreak of tail biting in pigs

Automatic early warning of tail biting in pigs: 3D cameras can detect lowered tail posture before an outbreak. By Richard B. D’Eath, Mhairi Jack, Agnieszka Futro, Darren Talbot, Qiming Zhu, David Barclay, Emma M. Baxter. 2018. PlosOne.


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.

Toys and tail docking may reduce stress from mixing of pigs after weaning

Teeth clipping, tail docking and toy enrichment affect physiological indicators, behaviour and lesions of weaned pigs after re-location and mixing. By Fu, Lingling, Zhou, Bo, Li, Huizhi, Allan P. Schinckel, Liang, Tingting, Chu, Qingpo, Li, Yuan, Xu, Feilong, 2018. Livestock Science 212: 137-142.


• Re-location and mixing after weaning brought stress to weaned pigs.

• Toy enrichment decreased the stress of mixing after weaning.

• Pigs with intact teeth and tail got more lesions after mixing.

• Weaner pigs with intact teeth and tail should avoid to be mixed after weaning.

Abstract Re-location and mixing after weaning increase the risk of aggression in weaned pigs. To quantify the effects of tail docking, teeth clipping and toy enrichment on the growth performances, behaviour, lesions, and physiological indicators of weaned pigs after re-location and mixing, a total of 262 weaned pigs from four pig processing treatments were selected and regrouped to two enrichment treatments within each processing treatment. The experimental newborn piglets from 24 litters were treated tail docking and teeth clipping at 3 d of age and weaned at 24 d of age. At 30 d of age, pigs in each treatment were weighed, re-located to a nursery room and mixed into 2 pens. Eight rubber toys were installed in one of two pens in each group. The behaviour of weaned pigs was recorded and observed at 1, 2 and 3 d after mixing. At 3 and 6 d before mixing and 1, 3 and 6 d after mixing, lesions on the body and tail, body surface temperature (BST), respiration rate (RR) and salivary cortisol concentrations were determined. At 85 d of age, all experimental pigs were weighed again. Mortality rate, average daily gain (ADG), and feed efficiency of pigs were recorded. Pigs with clipped teeth performed less negative social behaviour (aggressive attacks/fight) (P < 0.05) and more positive social behaviour (non-aggressive social interactions) (P < 0.01) than pigs with intact teeth. Pigs with docked tails performed more positive social behaviour (P < 0.01) than pigs with intact tails. Toy enrichment decreased (P < 0.05) lesions on the ear and front body of pigs, and pigs with docked tail got fewer lesions on the tail (P < 0.01). Intact teeth increased (P < 0.01) RR, while toy enrichment decreased (P < 0.05) RR of pigs. Teeth clipping, tail docking and toys had no effects (P > 0.05) on ADG, body weight and mortality rate of pigs from 30 to 85 d of age. These results indicate that toy enrichment and pig processing treatments have positive effects on weaned pigs after re-location and mixing.

Providing enrichment to alleviate pain due to castration and tail docking in pigs

Evaluating environmental enrichment as a method to alleviate pain after castration and tail docking in pigs. By Brittany L. Backus, John J. McGlone, 2018. Applied Animal Behaviour Science 204: 37-42.


• Enrichment did not mitigate pain associated with management procedures.

• Enrichment had a positive effect on growth, activity and immunity.

• Enrichment improved pig welfare even if it did not mitigate piglet processing pain.

Abstract Castration and tail docking are common management practices performed on commercial swine farms in the US and around the world to reduce adverse behaviors and the occurrence of boar taint. However, these practices themselves are a welfare concern for the piglet because they cause acute pain. The provisions of environmental enrichment (EE) may reduce anxiety, protect from stressors, influence pain sensitivity, and improve the overall welfare of animals. Our objective was to determine if EE can reduce the physiological and behavioral stress response caused by castration and tail docking in piglets over time. Sows were randomly assigned to control farrowing stalls (CON; n = 9) or stalls enriched (ENRICH; n = 9) with newspaper, soil, ball and rope, so that EE was available to piglets upon birth. At 5 days old, ENRICH and CON piglets (n = 54 per treatment) were allocated to one of six piglet husbandry treatments; four boar piglets were randomly allocated to one of four treatments: 1) control handled (SHAM B), 2) tail docked (TAIL B), 3) castrated (CAST), or 4) castrated and tail docked (BOTH); and two gilt piglets were randomly allocated to one of two treatments: 5) control handled (SHAM G), or 6) tail docked (TAIL G). Live weight tended (P < 0.10) to be greater in all ENRICH pigs. Leukocytes and the neutrophil to lymphocyte ratio were decreased (P < 0.05) among ENRICH compared with CON piglets. ENRICH piglets were more active (P < 0.05) than CON piglets. Maintenance and play behaviors decreased (P < 0.05) 120 min after, but returned to baseline at 24 h. Cortisol was greater (P < 0.05) among CAST and BOTH piglets, but no differences were observed in cortisol concentrations between housing groups. Stress vocalizations were greater (P < 0.05) in CAST and BOTH compared with SHAM piglets, while all pig processing treatments displayed more (P < 0.05) pain behaviors than SHAM. The use of EE had no effect on reducing pain-induced stress of castration and tail docking. However, we found that pigs raised with EE were heavier and more active than pigs raised without enrichment. We also found that EE modulated the immune response in pigs. In conclusion, EE improved the overall welfare of pigs at an early age.

Risk factors for tail lesions in weaner pigs

Factors influencing the risk for tail lesions in weaner pigs (Sus scrofa). by Angelika Grümpel, Joachim Krieter, Christina Veit, Sabine Dippel, 2018. Livestock science 216: 219-226.


We identified five factors influencing the risk for tail lesions in weaner pigs.•

We can recommend regression tree analysis for describing tail lesion risk factors.•

Data interpretation should include information on correlations between variables.


Tail biting is a behavioural disorder in pigs which results in tail lesions. Many factors must be considered to reduce the risk for tail biting due to the multifactorial character of this behaviour. We developed a software-based tail biting management tool called “SchwIP” for analysing farm individual risk factors for tail biting in weaner pigs. SchwIP was applied on 25 conventional farms throughout Germany who kept weaner pigs in closed barns (median 1,800 weaning places). The farms were visited up to three times between August 2016 and November 2017 and a total of 368 pens were assessed. Data regarding enrichment, pen environment, feed, water, climate, health, farm management, transport and regrouping were analysed with regression tree analysis (RT) using pen level prevalence of tail lesions (%) as the outcome variable. There were five primary influencing factors for tail lesions: docking status, stocking density, daily weight gain, suckling piglet losses and number of litters mixed during weaning. The correlation between observed and predicted prevalence of tail lesions across all pens was 0.6. Most of the factors may represent combinations of influences on a farm which agree with the multifactorial nature of the problem. Even though weight gain may also be influenced by tail biting behaviour and thus be a parallel outcome, it could be used by farmers as an indicator for initiating closer examination and intervention. The use of RT for visualising complex risk factor analyses is recommendable, though their analytical suitability for clustered data should further be evaluated.

Optical flow to monitor tail biting outbreaks in pigs.

Utilization of optical flow to monitor development of tail biting outbreaks in pigs. By Y Li, H Zhang, L Johnston, M Dawkins, 2018. Journal of Animal Science 96: 519.


This study was conducted to evaluate activity changes in pigs associated with outbreaks of tail biting using an optical flow platform. Pigs (n=240, 24.9 ± 2.9 kg, 9-wk old) were housed in 8 pens of 30 pigs on slatted floors for 16 weeks. Four pens housed pigs with tails docked and the other 4 pens housed pigs with tails intact. Pigs were assessed for tail scores (0=no injury to 4=severe injury) once weekly. Behaviors of pigs were video-recorded twice weekly. One-hour video segments during morning, noon, and afternoon of each recording day were analyzed for optical flow using the OPTICFLOCK platform which measures movements of pigs in each pen. The same video segments were scanned at 5-min intervals to estimate time budget for standing/walking, lying, eating, drinking, and tail biting. Compared with docked pigs, intact pigs had higher tail scores (0.5 ± 0.29 vs. 0.1 ± 0.01; P < 0.001) and higher optical flow (8.2 vs. 6.9; SE=0.42; P < 0.05), suggesting more tail injuries and higher activity levels. Intact pigs spent less time lying (P < 0.001) and more time eating (P < 0.01) and tail biting (P < 0.01), and tended to spend more time standing/walking (P=0.08) than docked pigs, which support the optical flow data. During outbreaks of tail biting, intact pigs had higher optical flow during the first outbreak (14.59, SE=0.73; P < 0.05) compared to before (5.44) and after (10.54) the outbreak, suggesting activity changes during the development of tail biting outbreaks. Across tail docking treatments and observation days, pigs had lower optical flow at noon (6.9, SE=0.33; P < 0.001) compared to morning (7.8) and afternoon (7.9), suggesting that pigs were less active at noon which was supported by the behavioral time budgets. These results suggest that optical flow might be a promising tool for monitoring activity changes in pigs during the development of tail biting.

Webcast Rearing pigs with intact tails -Expert meeting November 27-28, 2018 Grange

Animal Welfare: Event about progress on rearing pigs with intact tails

[Original text taken from the EU site]
Tuesday 27 – Wednesday 28 November

Dunsany, C15DA39, Ireland (live streaming available)

The European Commission is organising a two day meeting from 27 to 28 November 2018, sharing valuable insights from top EU experts on progress with rearing pigs with intact tails and thus improving their welfare.

The meeting, which will take place at the Commission’s Health and Food audit and analysis Directorate in Ireland, will be available via web streaming (see web-links below).

The topics presented are especially of interest for industry stakeholders, authorities in EU Member States, researchers, and NGOs interested in the welfare of pigs, as they focus on ongoing work to improve rearing conditions on farms to assist in the phasing out of routine tail-docking of pigs and managing the risk factors relating to tail biting.

The group of expert speakers include pig farmers and industry representative organisations, EU Member State competent authorities, research bodies, NGOs and EU institutions.  Discussions will focus on what has been done, and what remains to be done, to get better solutions for the future. The work of the newly created EU Reference Centre for Animal Welfare, focussing initially on pigs, will also be presented at this meeting. A more detailed agenda will be uploaded once all speakers have been confirmed.

Please note: The proceedings of this meeting, apart from table discussions, will be broadcast live and can be followed via the following links:

Day 1 – 27 November 2018 – 09:00-18:00

Day 2 – 28 November 2018 – 09:00-15:00

The presentations can be viewed here.

An animal‐based screening method for sufficient amount of straw to fulfil the need for exploration and manipulation

An animal‐based screening method for sufficient amount of straw to fulfil the need for exploration and manipulation

By Margit Bak Jensen and Lene Juul Pedersen, October 19, 2018

This document describes a screening method to assess if pigs are supplied with a sufficient amount of straw to fulfil their need for exploration and manipulation through collection of data on the availability of straw, pigs’ exploratory behaviour and lesion scoring.

Read more: An animal‐based screening method for sufficient amount of straw to fulfil the need for exploration and manipulation

Tail amputation causes acute and sustained changes in peripheral somatosensory nerve function involving inflammatory and neuropathic pain pathways

Oral presentation

 Recent Advances in Animal Welfare Science (VI),

UFAW Animal Welfare Conference, Centre for Life, Newcastle, UK 28th June 2018

Coexpression analysis of dorsal root ganglia from tail amputated pigs at different ages reveals long-term transcriptional signatures associated with wound healing and inflammation, and neuropathic pain pathways

DA Sandercock1, JE Coe1, MW Barnett2, TC Freeman2, P Di Giminiani3 and SA Edwards3

1 Animal and Veterinary Science Research Group, SRUC, Edinburgh UK,

2 The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh UK

3 School of Agriculture, Food and Rural Development, Newcastle University, Newcastle-upon-Tyne, UK

 Concerns exist that docking and biting injuries may be a cause of long term pain in the remaining tail stump during the pig’s lifetime. The potential for long-term pain has been linked to sustained cellular and molecular changes in peripheral sensory neuronal activity. The aim of this study was to conduct a transcriptome analysis of caudal dorsal root ganglia (DRG) gene expression profiles from pigs subjected to tail amputation, in particular examining genes known to be associated with inflammation and neuropathic pain. Microarray analysis was performed on caudal DRG from sham (control) and tail amputated pigs 1, 8 and 16 weeks after tail treatment at either 3 days (neonate) or 63 days (juvenile). Tail amputation injury induced highly significant gene expression changes (both up and down) compared to sham-treated intact controls at both ages (518-2,794 genes, FDR < 0.05) that were still evident 16 weeks after tail amputation. Network correlation analysis using the Markov clustering (MCL) algorithm to define expression modules revealed two highly correlated (PCT r2 = ≥0.75), interrelated transcript expression clusters related to (A) neuronal function (759 genes) and (B) wound healing (273 genes). In cluster A, gene ontology (GO) and pathway enrichment analysis identified genes with significant GO terms for voltage- and ligand-gated ion channel activity linked to regulation of membrane potentials, neurotransmitter levels and synaptic signalling. In cluster B significant gene expression was associated with receptor binding, protein transcription activity and regulation, linked to processes such as response to wounding, regulation of response to wounding, inflammatory response and activation of immune response. Cross-reference against an integrated database of known genes involved in the regulation of inflammatory and neuropathic pain revealed 124 and 61 pain–associated genes in clusters A and B, respectively. Key functional families of ion channels and receptors were significantly down-regulated in cluster A, in particular voltage-gated potassium channels and GABA receptors which are linked to increased neuronal excitability. Up-regulated functional gene families in cluster B were mostly linked to inflammation, macrophage activity, neurohormone and opioid peptide activity. DRG gene expression profiles appear to be linked to sustained tissue inflammation and remodelling (ca. 4 months) and pain perception modulation consistent with adaptive, compensatory responses to injury induced increases in peripheral sensory neuron excitability in the injured tail stump. Tail amputation causes acute and sustained changes in peripheral somatosensory nerve function involving inflammatory and neuropathic pain pathways which have implications for pig welfare.