Category Archives: Tail docking

Did European pig-welfare legislation reduce pig welfare? Perhaps not, but experts confirm that common indestructible materials are not proper enrichment for pigs at all, except perhaps for an enhanced novel branched-chains design.

Published as:
Marc B.M. Bracke and Paul Koene, 2019. Expert opinion on metal chains and other indestructible objects as proper enrichment for intensively-farmed pigs. PLOS ONE. Available at http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0212610.

EC Directive 2001/93 requires that all pigs have access to proper investigation and manipulation materials. Intensively farmed pigs in Europe are frequently provided with a short/bare metal chain with or without an indestructible object attached to the chain. To date authorities are regarding this as proper enrichment. However, it has become increasingly clear that the chains do not provide proper enrichment, and that adding an indestructible object such as a ball, pipe or hard wood to the end of the chain may even reduce pig welfare. To test this hypothesis an expert survey was conducted. In total 36 international experts, mostly pig-welfare scientists, responded to the survey.

The experts only marginally agreed with the hypothesis (agreement score 4.6 on average on a scale from 0-10). However, indestructible materials generally received very low scores for welfare, indicating they did not provide proper enrichment. Ranked from low to high average welfare score, the objects were grouped in 5 significance levels:

Level 5 (totally insufficient): Chain hanging too high (for most of the smallest pigs in the pen; average score 1.3 on a scale from 0 to 10 where 5.5 would be ‘acceptable’)

Level 4 (extremely insufficient): Short chain (3.1), Small ball (2.8) and Big ball (average 2.5)

Level 3: (very insufficient) Pipe (3.5) and Bare chain (3.3)

Level 2-3 (very/rather insufficient): Hard wood (3.7)

Level 2 (rather insufficient): Chain on the floor (average: 4.4)

Level 1 (almost sufficient): Branched chains (5.1)

Compared to the marginal enrichment provided before the EC Directive 2001/93 was implemented in 2007 (in the Netherlands generally a short/bare chain, scoring 3.1 and 3.3 respectively, i.e. Level 3-4), adding balls or pipe , as commonly done in The Netherlands and Germany, does not improve pig welfare. Hard wood, as practised esp. in the UK, is a most marginal improvement (only 0.4 higher on average than Bare chain). Chain on the floor scored a bit better (4.4), without being acceptable (set at 5.5). The ‘new’ Branched chains scored significantly better than all other indestructible materials and its welfare score (5.1 on average) was close to the pre-defined level of acceptability (5.5 on a scale from 0, worst, to 10, best). The welfare benefits of adding balls, pipes or hard wood to the metal chain were marginal, and well below what the experts considered acceptable enrichment. The branched-chains design, by contrast, appears to be the most viable alternative. It involves providing a longer chain, i.e. with the free end reaching to floor level, adding ‘branches’, i.e. several short chains ending at the nose height of the pigs, and providing more chains per pen (i.e. 1 branched chain per 5 pigs). Therefore, the implementation of current pig-enrichment legislation needs revision. Branched chains should be implemented widely (across the globe) and in the short term as a first step towards, and benchmark for, providing proper enrichment to intensively-farmed pigs.

See also the related publication and posts on this website:

Chains as enrichment for pigs (Book chapter with supplement)
Pig animation – Improved, branched chain design as proper enrichment for pigs
Branched chains as enrichment for pigs (technical description, pictures and video)
Proper enrichment for intensively-farmed pigs – From review to preview
A collection of pictures of other enrichment materials for pigs can be found here: Prize contest (Prijsvraag) 2011.
Do pigs play with chains? Science versus society

Original abstract of the PLOS ONE paper:

Marc B.M. Bracke and Paul Koene, 2019. Expert opinion on metal chains and other indestructible objects as proper enrichment for intensively-farmed pigs. PLOS ONE. Available at http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0212610.

Abstract

EC Directive 2001/93 requires that all pigs have access to proper investigation and manipulation materials. Intensively farmed pigs in Europe are frequently provided with a short metal chain with or without an indestructible object attached to the chain. To date authorities are regarding this as proper enrichment, perhaps with (in)direct reference to the RICHPIG model as a justification. However, it has become increasingly clear that the chains do not provide proper enrichment, and that adding an indestructible object to the end of the chain may even reduce rather than improve pig welfare. To test this hypothesis an expert survey was conducted containing 26 more or less compound questions. On a scale from 0 to 10 experts specified their level of agreement with the hypothesis, the prevalence and welfare scores of nine indestructible enrichment materials. In total 36 experts, mostly pig-welfare scientists, responded (response rate: 39%). Indestructible objects are less prevalent in countries that provide straw (like Sweden and the UK) and outside the EU (US). They are more prevalent in the Netherlands, Belgium, France and Finland, while the prevalence seems to be low in Spain. Balls, wood and pipes were provided most frequently: hard wood especially in the UK (as specified in farm assurance); indestructible balls and pipes in Germany and the Netherlands. The experts’ score for agreement with the hypothesis was only 4.6 on average (scale 0-10; n=25). Enrichment materials, ranked from high to low welfare score, were grouped in 5 significance levels as indicated by different superscripts based on Wilcoxon signed rank tests: Branched chains (5.1a), Chain on the floor (4.4b), Hard wood (3.7bc), Pipe (3.5c), Bare chain (3.3c), Short chain (3.1d), Small ball (2.8d), Big ball (2.5d), and Chain hanging too high (1.3e). Branched chains scored significantly better than all other indestructible materials and its welfare score (5.1 on average) was close to the pre-defined level of acceptability (5.5 on a scale from 0, worst, to 10, best). The welfare benefits of adding balls, pipes or hard wood to the metal chain were marginal, and well below what the experts considered acceptable enrichment. The branched-chains design, by contrast, appears to be the most viable alternative. It involves providing a longer chain, i.e. with the free end reaching to floor level, adding ‘branches’, i.e. several short chains ending at the nose height of the pigs, and providing more chains per pen (i.e. 1 branched chain per 5 pigs). Branched chains should be implemented widely and in the short term as a first step towards, and benchmark for, providing proper enrichment to intensively-farmed pigs.


Branched chain
Two organic pigs interacting simultaneously with a branched chain in the snow. Despite access to a straw bed for rooting, even organic pigs may interact with such chains for long periods of time, esp. directed towards the floor. In fact they will root the chain on the floor more than twice as much as playing with it in a horizontal position. In intensive pig production chains are often (too) short, and when a hockey-type ball or ‘sustainable’ plastic pipe is attached to the end of such a chain the pigs’ interest, and their welfare, is often even reduced further.
Two pigs playing simultaneously with a preferred anchor-type branched chain design.

This post was published originally on the personal website of the first author (see here).

Dealing with tail biting in pigs with intact tails

PigProgress – Early indicators for tail biting in pigs Should pigs in the EU keep the end of their tails, or should tails be docked in the 1st days of the pigs’ lives to reduce risk of tail biting? The subject is widely discussed which also underlines that there is no easy answer. However, there is work in progress and so are some very promising results, writes pig welfare expert Vivi Aarestrup Moustsen. Read more in Pig Progress

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 210: 26-37. 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.

Abstract

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.

Abstract

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.

Highlights

• 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.

Highlights

• 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.

Highlights

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.

Abstract

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.

Abstract

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.