Tag Archives: pigs

Agent-based modelling in applied ethology: An exploratory case study of behavioural dynamics in tail biting in pigs

Agent-based modelling in applied ethology: An exploratory case study of behavioural dynamics in tail biting in pigs. By Iris J.M.M. Boumans, Gert Jan Hofstede, J. Elizabeth Bolhuis, Imke J.M. de Boer, Eddie A.M. Bokkers. 2016. Applied Animal Behaviour Science


Understanding behavioural dynamics in pigs is important to assess pig welfare in current intensive pig production systems. Agent-based modelling (ABM) is an approach to gain insight into behavioural dynamics in pigs, but its use in applied ethology and animal welfare science has been limited so far. We used ABM in a case study on tail biting behaviour in pigs to explore the use of ABM in gaining more insight into emergent injurious pig behaviour and related welfare issues in intensive production systems. We developed an agent-based model in Netlogo 5.1.0 to simulate tail biting behaviour of pigs housed in conventional pens in groups of 10. Pigs in the model started as neutral pigs (not involved in biting incidents), but could change into a biter, victim, or both biter and victim. Tail biting behaviour could emerge when pigs were unable to fulfil their internal motivation to explore. The effects of a redirected exploratory motivation, behavioural changes in victims and preference to bite a lying pig on tail biting patterns were tested in our model. The simulations with the agent-based model showed that coincidence in development of a redirected exploratory motivation can lead to tail biting behaviour in pigs and can explain the strong variations in incidence of tail biting behaviour observed in conventionally housed pigs. Behavioural changes in victims and preference to bite a lying pig seem to be of minor importance in the causation of tail biting patterns. The behavioural time budget of a pig might be an important factor in predisposing pigs to or preventing them from becoming a tail biter or a victim. ABM showed to be useful in analysing behavioural dynamics and welfare issues. An advantage for ABM in applied ethology is the availability of data from empirical studies.

On-farm tail biting prevention in long-tailed pigs – results from a producer questionnaire in Finland

On-farm tail biting prevention in long-tailed pigs – results from a producer questionnaire in Finland. By Valros, A., C. Munsterhjelm, L. Hänninen, T. Kauppinen, M. Heinonen, 2016. Royal Dublin Society: Abstracts book of the 24th International Pig Veterinary Society (IPVS) Congress, Dublin, Republic of Ireland 7-10th June 2016. p. 144.


Introduction: Tail biting is a serious welfare problem in pigs, causing substantial economic losses. In the majority of the EU countries, tail docking is used to reduce the incidence of tail biting. However, many of the risk factors for tail biting are related to suboptimal management, and tail biting can be reduced by corrective management decisions. There are few studies on which preventive measures producers themselves value as most important.

Materials and Methods: A questionnaire was distributed via slaughterhouse webpages in 2015. Producers were asked to score the importance of handling different tail-biting risk factors on their own farms, as well as about which manipulable materials they use, and find efficient. In addition, we asked about their opinions on tail biting and tail docking. A total of 70 producers replied, 54 of these replies were regarding fattening pigs, and 16 regarding weaned pigs. The size of the pig units varied between 100 and 6400 pigs, with an average of 1307 pigs. Finland banned tail docking in 2003, so all farms raised long-tailed pigs only.

Results: On average, the producers reported a prevalence of tail biting of 2,3% on their farms, which corresponds well with values reported at Finnish abattoirs. Most producers found tail biting not to be a big problem on their farms and 62% of the farmers found it very unlikely that they would raise tail docked pigs even if it was legal in Finland. The more tail biting reported on the farm, the more problematic the farmers found tail biting, and the more prone they were to say they would probably tail dock if they were allowed to. According to the Finnish producers, the most important factor to prevent tail biting is that there is enough feeding space for the pigs. Altogether, four feeding-related risk factors were included in the top-10 measures to prevent tail biting. Also pig health was considered very important, as well as a good quality of piglets, and controlling air movements in the pen. Straw, newspaper, hay and cardboard were considered the most efficient manipulable materials to prevent tail biting. If tail biting has already started in the pen, the producers ranked identifying and removing the tail biter from the pen as most important, followed by adding bedding-type manipulable materials.

Conclusion: The results are partly in accordance with experimental and epidemiological studies on risk factors for tail biting, but the high focus on feeding-related and health factors is interesting. Finnish farmers appear to handle the tail docking ban well, and do not, on average, find tail biting a very serious problem.

The perception of pain by pigs and implications for farm and veterinary practice

The perception of pain by pigs and implications for farm and veterinary practice. Edwards, S., 2016. Royal Dublin Society: Abstracts book of the 24th International Pig Veterinary Society (IPVS) Congress, Dublin, Republic of Ireland 7-10th June 2016. p. 13-17.


“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.

Paper available in the proceedings.

Traumatic neuroma development in tail docked piglets is not associated with long-term changes in spinal nociceptive processing

Traumatic neuroma development in tail docked piglets is not associated with long-term changes in spinal nociceptive processing. By Sandercock, D., S. Smith, J. Coe, P. Di Giminiani, S. Edwards, 2016. Royal Dublin Society: Abstracts book of the 24th International Pig Veterinary Society (IPVS) Congress, Dublin, Republic of Ireland 7-10th June 2016. p. 611.


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.

Poster Sandercock IPVS

FareWellDock Edinburgh Satellite Meeting

On July 12th the FareWellDock consortium hosted a satellite meeting and videoconference at the Roslin Institute Building near Edinburgh to coincide with the 50th conference of the International Society for Applied Ethology. The aim of the satellite meeting was to invite researchers involved in other European projects on tail docking and biting to share their work and ideas with the consortium.

The speakers gave four excellent presentations which generated interesting discussions and more ideas for planning future work (see brief summaries below)

Updates of the three work packages were also presented at the meeting. Since the last meeting in March, several more articles on tail docking and biting have been published and a number are near completion. Work progress in all three work packages appears to be on track.

Emphasis was placed upon generating and circulating draft fact sheets from the 3 work packages before the FVO Stakeholder Meeting in Grange, Republic of Ireland on October 4-6th 2016.

Sabine Dippel, a researcher at the Federal Research Institute of Animal Health (FLI), provided a comprehensive overview of “Current tail biting projects in Germany” and the summarised outputs from 51 different projects ranging from those focussed on basic science to feasibility and survey-based studies. Preliminary findings suggested that:
• Undocked weaner pigs were at higher risk of tail biting than undocked fattening pigs.
• Farmers need to gain experience in observing pigs
• Farms need to change step-by-step towards intact tails
• Focus on farm-individual optimisation
• Greater coordination between production stages
• Advice, training, knowledge transfer were essential to achieving these aims
Tail biting pigs
Valérie Courboulay a researcher at IFIP (French Institute for the pig and pork industry) provided an overview of several IFIP related studies on tail biting and dissemination of information in the form of technical datasheets to French farmers. Data presented from studies where pain relief (meloxicam) was provided at the time of docking and castration showed marginal affects on general behaviours, except for increased time spent sitting. When investigating tail posture, pigs with more severe tail lesions (score 3) exhibited more tail-down posture than pigs with minor tail or no tail lesions (score 2-0). A recent study has been undertaken to develop a model of cannibalism in pigs based on frustration of exploratory behaviours by providing environmental enrichment (progressive supply) and straw in the post weaning period and then some groups were reared with or without environmental enrichment for a short duration in the fattening period. The results showed that:
• Removal of enrichment between the post weaning and fattening periods is not sufficient to induce tail biting
• Providing objects for a few days and removing them is not sufficient to induce tail biting
• Frustration of investigative behaviour, that is considered as a major risk factor, is not sufficient to induce tail biting

INRA factsheet on pain

Jen-yun Chou, a first year PhD student working at Teagasc in the Republic of Ireland, presented preliminary findings from her studies into the use of wood as a strategy to reduce the risk of tail biting in pigs managed on slatted floors. The potential use of wood as a manipulable material is viewed positively in Irish production systems due to the problems of slurry removal caused by loose straw in fully slatted systems. To date, preliminary data have shown that softwoods such as spruce and scots pine are more readily used by the pigs compared to more hardwoods such as larch and beech.
• Spruce was used up most quickly both in terms of length and weight loss, possibly due to its softness.
• There is a tendency of more interaction with the wood by pigs in pens provided with spruce.
• In terms of texture and moisture spruce is a good option for enrichment but the cost may be a drawback
• Different wood types did not affect harmful behaviours, pig physical measures and production.
• Correlation between ear lesion and tear staining scorings implies a potential welfare assessment method on farm due to easy visibility.
• Correlation between tail posture and lesion shows that posture could be an indicator of tail biting

Chewed wood

Anna Sinclair, a first year SRUC PhD student currently working at the Institut National de la Recherché Agronomique (INRA), presented preliminary findings from studies into the behavioural and neural/cellular consequences of tooth resection in commercial pigs at its implications for pig welfare. Although this work was not directly related to tail docking or biting it is a project that was developed through on-going collaborative research by Dr. Armelle Prunier ay INRA and Dr. Dale Sandercock at SRUC within the FareWellDock project, addressing the issue of early life pain in livestock. Preliminary data were presented on the effects of tooth clipping and tooth grinding on tooth length and tooth/gum injury, haematological measures, live weight/growth rates, general, stress and pain related behavioural measures. Findings to date have shown that:
• Tooth damage was readily observed but variable
• Maxillary incisors are most consistently affected
• Clipping results in tooth and gum bleeding
• Growth rates are unaffected
• Pigs exhibit reduced activity after tooth treatments
• Pigs keep their ears back less and their tails down more, although this could be handling effect
• High variation at this stage – more data are required

Tooth treatment

Behavioural differences between weaner pigs with intact and docked tails

Behavioural differences between weaner pigs with intact and docked tails
By Paoli, MA; Lahrmann, HP; Jensen, T; D’Eath, RB, 2016. Animal Welfare 25: 287-296.


Tail-biting in pigs (Sus scrofa) reduces welfare and production. Tail-docking reduces (but does not eliminate) tail-biting damage. The reason tail-docking reduces tail damage is unknown. It may reduce pigs attraction to tails (H1), or increase tails’ sensitivity to investigation (H2). To investigate these hypotheses, behavioural differences between 472 individually marked grower pigs with intact tails (nine groups of 25–34 pigs) or docked tails (nine groups of 22–24 pigs) were observed from 5–8 weeks of age on a commercial farm in Denmark. Pens had part-slatted floors, dry feeding and two handfuls of straw per day, and enrichment objects were provided. Behavioural sampling recorded actor and recipient for tail-directed (tail interest, tail in mouth, tail reaction) and investigatory behaviours (belly-nosing, ear-chewing, interaction with enrichment). Scan sampling recorded pig posture/activity and tail posture. Intact-tail pigs performed more overall investigatory behaviours but tail type did not affect the amount of tail-directed behaviours. Larger pigs performed more investigatory and tail-directed behaviours than smaller pigs and females performed slightly more tail investigation. Tail-directed behaviours were not consistent over time at the individual or group level. However, ear-chewing was consistent at the group level. One group with intact tails was affected by a tail-biting outbreak in the final week of the study (evidenced by tail-damage scores) and showed an increase over time in tail posture (tail down) and tail-directed behaviour but not activity. Overall, there were few behavioural differences between docked and undocked pigs: no evidence of reduced tail investigation (H1) or an increased reaction to tail investigation (H2) in docked pigs, and yet docked pigs had less tail damage. We propose that docking might be effective because longer tails are more easily damaged as pigs are able to bite them with their cheek teeth.

Understanding tail biters and victimized pigs during outbreaks of tail biting

Understanding tail biters and victimized pigs during outbreaks of tail biting
By Y. Li, J. Anderson, A. Holten, A.M. Hilbrands, J. Holen and L.J. Johnston, 2016. Jounal of Animal Science 94, suppl 2: 2, p. 8-9.


Tail biting is a common problem in growing–finishing pigs, which can compromise health, growth, and welfare of pigs. Because tail biting is an abnormal behavior performed by tail biters toward victimized pigs, understanding these pigs may help us solve the problem. This study was conducted to evaluate immune function of tail biters and victimized pigs. Pigs (n = 240; 25.7 ± 2.9 kg initial weight) were housed in 8 pens of 30 pigs for 16 wk. Once visible blood on a tail appeared, pigs in that pen were assessed daily for tail score (0 = no damage, 1 = healed lesions, 2 = visible blood without swelling, 3 = swelling and signs of infection, and 4 = partial or total loss of the tail). Victimized pigs were defined as pigs with tail scores equal to or greater than 2. Meanwhile, a 2-h observation was conducted for 2 consecutive days to identify tail biters. In each pen in which tail biting occurred, blood samples were collected from victimized pigs on the day that tail biting was first observed as well as from tail biters and 2 control pigs with no sign of tail damage. Fourteen biters (6 barrows and 8 gilts), 30 victimized pigs (21 barrows and 9 gilts), and 28 control pigs (14 barrows and 14 gilts) were identified for blood sampling. Total serum protein and IgG concentrations were analyzed using the spectrophotometric method. Data were analyzed using the Glimmix model of SAS (SAS Inst. Inc., Cary, NC). Compared with control and victimized pigs, tail biters had lower total serum protein (P = 0.01; Table 018) and IgG concentrations (P = 0.01), suggesting poor immunity. There were no differences in total serum protein or IgG concentrations between control and victimized pigs. These preliminary results suggest that tail biters may experience compromised immunity.

Influence of tail docking, with or without a cold analgesic spray, on behaviour, performance and physiology of piglets

Influence of tail docking, with or without a cold analgesic spray, on behaviour, performance and physiology of piglets
By Armelle Prunier, Gaëlle Bataille, Marie-Christine Meunier-Salaün, Aline Bregeon, Y. Rugraff. 2001. Journées Rech. Porcine en France, 33, 313-318. (Article in French).


Tail docking performed in order to avoid tail biting in fattening pigs is criticized. In order to assess its short term consequences, two experiments were realized. The first one performed on 160 piglets from 32 litters was focussed on the behavioural consequences and the growth performance. The aim of the second one was to determine the effects of tail docking on the adrenal (plasma cortisol and ACTH) and sympathetic (measurement of glucose and lactate released from catecholamine-induced mobilization of glycogen) axes in 20 piglets from 7 litters which were catheterized at birth. In the first experiment, there were 5 treatments: tail docking, tail docking + a cold analgesic spray, control handling, control handling + spray, no handling. In the second experiment, the same treatments were run, except the fourth one. Treatments were applied the day after birth and tail was docked with an iron docking (cautery). During treatment, tail docking caused more movements (legs and/or body) and howls (P < 0.05). During the 20 s following treatment, docked piglets demonstrated more tail jamming and wagging (P < 0.05). Both types of docking consequences were attenuated when the cold spray was used. During the following 12 hours, time spent by the piglets to rest or to be active at the sow udder was similar in the 5 groups. Growth rate during the first week of life and the occurrence of injuries at the tail did not differ between groups (P > 0.1). Tail docking with or without the cold spray had no marked effects on the patterns of plasma cortisol, ACTH, glucose and lactate. In conclusion, tail docking causes probably pain of moderate amplitude.

Impact of tail docking on behaviour of suckling piglets

Impact of tail docking on behaviour of suckling piglets
by Céline Tallet, Marine Rakotomahandry, Sabine Herlemont, Armelle Prunier, 2016. Journées Recherche Porcine, 48, 235-236 (Article in French).


Tail docking is still applied in Europe to prevent tail biting, despite its evident negative impact on pig welfare. We aimed at characterising consequences of tail docking on suckling piglets. We compared 48 piglets with tail docked (C) to 50 undocked piglets submitted to a non-painful simulation of docking (S). Their behavioural reaction during docking and for 20 s following the process was observed: vocalisations, tail posture and movements. Observations were repeated on C animals and on 48 other animals left intact from birth (I), 4 h after the docking process, 3 days after and once a week, in addition giving a score to the state of the tail. Fifteen days after birth, their reaction to a motionless seated human was observed. The C piglets vocalised more and louder during the docking process than S piglets (P < 0.05). For the 20 s after docking, their tail remained immobile longer (P < 0.05). The tail was also more immobile during the whole suckling period (P < 0.05). The C piglets approached the unfamiliar human later than the I piglets (P < 0.05). The I piglets tended to have more tail lesions than the C group (P < 0.1) during suckling. Tail docking thus induces reactions indicating pain on the day of docking and throughout the suckling period. Evidence of first episodes of tail biting were also found in I pigs. Longer term effects remain to be characterised (pain and bitings).

Impact of straw on gastric ulceration in pigs

Impact of the amount of straw provided to pigs kept in intensive production conditions on the occurrence and severity of gastric ulceration at slaughter.
Herskin MS, Jensen HE, Jespersen A, Forkman B, Jensen MB, Canibe N, Pedersen LJ. 2016. Res Vet Sci. 104: 200-6.


This study examined effects of the amount of straw offered on occurrence and severity of gastric lesions in pigs kept in pens (18 pigs, 0.7m(2)/pig) with partly slatted flooring and 10, 500 or 1000g straw/pig/day from 30kg live weight. The pigs had ad libitum access to dry feed. Forty-five pigs were used, three from each of 15 pens. After euthanisia, the dimension of the non-glandular region of the stomach was measured. Lesions were characterized and scored. Irrespective of straw provided, 67% of the pigs showed signs of gastric pathology. Pigs provided with 500 or 1000g straw were pooled as ‘permanent access’. The proportion of pigs with ulcerations was reduced by permanent access to straw (7 vs. 33%; P<0.05), suggesting that permanent access to straw may improve animal health, and be considered as one possible strategy to limit gastric ulceration in pigs.

500gr straw/pig/day
500gr straw/pig/day
10gr straw/pig/day
10gr straw/pig/day