Monthly Archives: August 2016

Effects of administration of a local anaesthetic and/or an NSAID and of docking length on the behaviour of piglets during 5 h after tail docking

Effects of administration of a local anaesthetic and/or an NSAID and of docking length on the behaviour of piglets during 5 h after tail docking

By M.S. Herskin, P. Di Giminiani, K. Thodberg, 2016. Research in Veterinary Science 108: 60–67.

Highlights

  • Lidocain reduced signs of procedural pain during tail docking in piglets but did not affect behaviour during 5 h after the procedure.
  • Meloxicam had only very marginal effects on behaviour of the piglets during and up to 5 h after tail docking.
  • Tail docking led to behavioural changes throughout the 5 h observation period.
  • Tail docking length affected procedural and post-procedural behaviour of the piglets.

Abstract

In many countries, piglets are tail docked to prevent tail biting. The aim of this study was 1) to evaluate the efficacy of a local anaesthetic and/or NSAID to reduce pain caused by tail docking; and 2) to examine interactions with docking length. This was examined in 295 piglets docked by hot iron cautery 2–4 days after birth and based on behaviour during docking as well as the following 5 h. The study involved three main factors: local anaesthetic (Lidocain), NSAID (Meloxicam) and docking length. Either 100%, 75%, 50% or 25% of the tails were left on the body of the piglets. Irrespective of the tail length, tail docking led to signs of procedural pain, which could be reduced by administration of Lidocain. Preemptive use of Meloxicam did not affect the signs of procedural pain. The results show that tail docking led to behavioural changes throughout the 5 h observation period indicating that effects of this management routine are more persistent than earlier suggested, and suggesting that docking length may influence the post-surgical behaviour of piglets. By use of the present sites of injection and dosages, neither local anaesthetic nor NSAID had marked effects on post-surgical behavioural changes induced by tail docking. Hence, if tail docking is to be performed, more research is needed in order to develop practical methods for on-farm piglet pain relief.

Tail docking: The final cut?

Tail docking: The final cut? By Monique Pairis-Garcia. You can read the first part of this article here. For the second part see the original at the Pig Progress site (published August 8, 2016).

Tail docking is applied to young piglets to avoid a potential problem later of tail biting. However, should the root of the problem be looked at instead of using this preemptive measure?

Tail docking is routinely performed on farms as a means to decrease the prevalence of tail biting. Tail biting is an abnormal redirected exploratory behaviour that results in mild to severe injury of pen mate’s tails. Several factors have been associated with tail biting behaviour including environment, nutrition, gender, genetics and health status.

Tail docking of piglets has and continues to be highly criticised in both the US and Europe. This is primarily driven by the fact that tail docking is a painful procedure as indicated by changes to the physiology and behaviour of pigs who are tail docked.

Eliminate tail docking and control tail biting

Most recently, European countries have taken a stance to eliminate this management practice by managing the problems which lead to tail biting in the first place. Several research projects including FareWellDock have been established to provide scientific research to determine the best practices to eliminate tail docking and control tail biting. Although several factors can contribute to tail biting, research has consistently demonstrated that the absence of material for manipulation increases risk of tail biting. Several enrichment objects including chains, rubber hoses, car tires, straw and peat moss have shown to decrease tail biting but not necessarily eliminate the behaviour altogether.

Unlike the European approach, the US is nowhere near implementing the elimination of tail docking on farm. Tail docking is still performed routinely on commercial swine operations in the US. Farms which are not tail docking are either smaller farms which provide outdoor access to pigs or farms on specified animal welfare friendly programmes like Animal Welfare Approved, American Humane and Certified Humane.

For the second part of this article (on the probability of eliminating tail docking and the value of enrichment) see the original at the Pig Progress site (and see also the comment section).

 

What are the effects of tail docking on piglets?

What are the effects of tail docking on piglets? Interview with Dr Pierpaolo Di Giminiani by Vincent Ter Beek in Pig Progress (August 8, 2016). Here you find the first half of the interview. The whole article can be found on Pig Progress.

The practice of tail docking is applied to young piglets to avoid a potential later problem of tail biting. But are there effects of docking on piglets? Very few researchers have asked that question, found Dr Pierpaolo Di Giminiani, researcher at Newcastle University, UK.

Is a tail actually a sensitive part of the pig’s body? Dr Pierpaolo Di Giminiani thinks for a while and says, “That is a very good question! I would say it is not more or less sensitive than other parts of the body. The tail is full of neuro-anatomical structures responsible for the pain response. It is comparable to our human skin.” Unlike in many other animals, the pig’s tail may not have a wide range of functions. At best it serves to chase insects away and when in a curl, it gives an indication of the animal’s health. Still, when something happens to that tail, whether this be being docked or bitten, this body part responds like any other.

Biography

Dr Pierpaolo Di Giminiani is a research associate with a focus on ethology (animal behaviour) at Newcastle University, UK. During his graduate studies at Linköping University in Sweden, he studied the cognitive impairment caused by anaesthetic protocols in rodents. At his doctorate at Aarhus University, Denmark, he focused on the assessment of behavioural measures of pain in pigs as a result of cutaneous inflammation. Currently, he investigates pain in pigs in relation to the practice of tail docking in piglets and tail injuries in older pigs.

Tail docking – and especially the effects of tail docking on piglets – has been the focus of Di Giminiani’s studies since the beginning of 2014. They form part of the FareWellDock research programme, an international conglomerate funded by the European Union, zooming in on the common problem of tail biting, the preventive solution of tail docking, virtually common everywhere in Europe, and what can be done to overcome both. Especially tail docking of piglets is a practice which is increasingly frowned upon in some European countries. For more information on FareWellDock, see box below.

Di Giminiani’s studies have mainly centred on the question of whether piglets in the short and long term suffer from any pain from tail docking. In an interview with Pig Progress, Di Giminiani points to pain being a very complex experience and it being difficult to measure properly. He says, “I find it fascinating because there is a lot that we can do, especially in a species like the pig. A lot has been done in humans and laboratory animals and we now have the opportunity to apply novel techniques in other animal species. In addition, pain mitigation is often not provided or done so arbitrarily due to the lack of valid measures of pain in non-verbal animals. Therefore, it still remains one of the big open questions in research.”

Measuring pain in animals

In many other animal studies, Di Giminiani explains, research on pain sensitivity is fairly common. Before he set himself onto the theme of pain in piglets, an academic journey took him from his native Italy to San Diego, United States and later Linköping, Sweden, to learn and discover more on pain perception in laboratory rodents.

In pigs, however, everything was different, he says, as similar research appeared to be virtually absent in pigs when starting his PhD in Denmark at Aarhus University. Indeed, a bit strange, considering that pigs have an important role to play virtually all over the world – and considering the fact that from a medical perspective, pigs and humans are very similar.

The current research on pain sensitivity around tail docking in piglets at Newcastle University roughly revolves around three questions, Di Giminiani explains:

Is pain actually occurring or not and how long does it last?
What is the level of pain experience for piglets?
Based on the outcome, what can be done – for instance the use of painkillers?
Di Giminiani says, “Basically, there are 2 common methods to assess pain in animals:

To observe spontaneous behaviour. You just observe the activity of the animals, e.g. how much they walk – their locomotion – how much they lie, how much they stand, how do they drink, how do they eat, etcetera.
“Another method revolves around stimulus and reception – how do animals react to certain controlled challenges? We apply a controlled challenge to evoke a reaction.” This last method had not been applied in pigs a lot, but was used at Newcastle University to figure out short and long-term effects of tail docking on piglets.
Di Giminiani’s research team applied a gas-heated iron for tail docking, so that any wound would immediately be closed to avoid infections. He says, “In addition to measuring responses to controlled stimuli, we developed a grimace scale to measure the facial expressions of piglets. They do seem to grimace, particularly that they squint with their eyes in the minutes immediately following tail docking.” A full scientific paper related to the findings will be sent for publication in the summer of 2016.

For the last three sections of this interview (Pain in animals in the longer term; Does it matter?; FareWellDock) see the original article, as well as several related articles, on the Pig Progress site.

Tail docking using hot iron cautery

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

Abstract

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.

Abstract

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.

Feeding behaviour and performance in relation to injurious tail biting in boars – a longitudinal study

Feeding behaviour and performance in relation to injurious tail biting in boars – a longitudinal study. By Munsterhjelm, C., J. Nordgreen, M. Heinonen, A. M. Janczak, A. Valros. 2016. Royal Dublin Society: Abstracts book of the 24th International Pig Veterinary Society (IPVS) Congress, Dublin, Republic of Ireland 7-10th June 2016. p. 627.

Abstract

Introduction: Automatically collected feeder data may be used to predict tail biting in finisher pigs.

Materials and Methods: Pen-level feeding behaviour and growth were investigated in relation to injurious tail biting (ITB), defined as visible wounds, from 10 weeks before to 4 weeks after the first ITB case in the pen. The data set included 36 pens of 10-12 intact boars between 43 and 148 kg, with average pen weight at ITB onset between 78 and 137 kg. A tail biting pen (TBPEN) had at least one case of ITB, whereas a control pen (CTR) had none. Individual feeding-related data including consumed feed, bout length and -frequency were collected by a single automatic ad libitum feeder. Time (week) relative to ITB onset was referred to as RELWEEK. The time before (PRE-ITB, RELWEEK -10 to 0, n=13 TBPEN and 23 CTR pens) and after ITB onset (POST-ITB, RELWEEK 0 to 4, n=9 TBPEN and 21 CTR) were analysed separately. Effects of TBPEN (vs CTR), bodyweight and RELWEEK were analysed using a linear mixed model with RELWEEK as repeated and pen as random effect.

Results: PRE-ITB the number of predicted feeder visits was lower in TBPEN as compared to CTR and decreased with age (PRED = -18 to -39% at RELWEEK -10 to 0; TBPEN effect p=0.02), leading to a tendency for a shorter daily time in the feeder (TBPEN effect p=0.06). TBPEN showed a growth dip to a -11% PRED level in RELWEEK -9 (TBPEN x RELWEEK p=0.001). Feeding behaviour changed in TBPEN in RELWEEK -2 to 0. Significant TBPEN x RELWEEK –interactions (p≤0.02) indicated that the relative decrease in the number of feeding bouts accelerated. Together with a progressive shortening of the average feeding bout this led to decreasing relative feed intake and growth (PRED= -10%, -7% and -8% at RELWEEK 0, respectively). POST-ITB TBPEN still spent less time in the feeder than CTR (TBPEN p=0.04), whereas the difference in the number of visits was decreasing (TBPEN x RELWEEK p<0.001). There was a tendency for a higher intake per second (TBPEN p=0.08) and a significantly faster RELWEEK-related increase in intake per visit (TBPEN x RELWEEK p<0.05), as well as increasingly faster growth (PRED= +9% at RELWEEK 4, TBPEN p=0.02) in TBPEN as compared to CTR. The amount of feed consumed did not differ.

Conclusion: Changes in feeding behaviour in TBPEN 10 weeks before ITB suggests presence of some tail-biting related factor. A growth dip 9 weeks before ITB may indicate the involvement of health problems in tail biting. Rapid changes in feeding behaviour suggest that tail biting behaviour begins or escalates 2 weeks before the first tail wounds are detected. TBPEN shows compensatory growth unrelated to feed intake in the month after ITB onset.

Poster Munsterhjelm IPVS

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.

Abstract

“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.

Abstract

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

Temporal changes in mechanical nociceptive thresholds in juvenile pigs subjected to surgical tail amputation: a model of injury induced by tail biting

Temporal changes in mechanical nociceptive thresholds in juvenile pigs subjected to surgical tail amputation: a model of injury induced by tail biting. By Di Giminiani, P., E. Malcolm, M. Leach, M. Herskin, D. Sandercock, 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. 649.

Abstract

Introduction: Tail biting is a global welfare problem in the pig industry leading to significant tail injury and potential carcass rejection. The temporal effects of such injuries and subsequent healing are presently unknown, although limb amputation in humans can lead to abnormal neural activity and decreased nociceptive thresholds. In order to evaluate potential sensitisation following tail damage, we created a model by surgical amputation of tails, and assessed mechanical nociceptive thresholds.

Materials and Methods: Surgical tail resection was performed to assess the influence of age, extent of tail amputated and time since amputation on thresholds of mechanical nociception. To evaluate the effect of age at the time of injury, female pigs underwent surgery at 9 weeks (±3 days ‘weaner’) (n=19) or 17 weeks (±3 days ‘finisher’) (n=43). The effect of time after amputation was evaluated on 24 pigs at 8 weeks, and 38 pigs at 16 weeks after surgery. The effect of the extent of tail amputated was assessed by assigning the pigs to 3 treatments (‘Intact’: sham-amputation; ‘short tail’: 2/3 of tail removed; ‘long tail’: 1/3 of tail removed). A Pressure Application Measurement device was used to record mechanical nociceptive thresholds (tail flick or tail clamp withdrawal responses). Within a single session, three stimuli were applied to a skin area proximal to the site of amputation, 3 days pre-surgery, 1 week and either 8 or 16 weeks post-amputation.

Results: Across the two amputation ages, results indicated that tail amputation induced a significant reduction (P<0.05) in mechanical nociceptive thresholds in short and long tails one week after surgery. The same treatment effect was observed at 16 weeks after amputation performed at 9 weeks of age (P<0.05). For surgeries performed at 17 weeks of age, thresholds tended to be lower in short compared to intact tails (P=0.081) and significantly lower (P<0.05) in long tail pigs 8 weeks after amputation. No significant difference was observed at 16 weeks following surgeries performed at 17 weeks of age.

Conclusion: These results show that surgical amputation of pig tails leads to decreased cutaneous mechanical nociceptive thresholds in the skin area proximal to the site of injury. Results indicated that severe tail injury occurring in the weaner period may be associated with sensitisation up to 16 weeks following the injury. In contrast, injuries occurring in the finishing period appeared to be associated with shorter lasting mechanical sensitisation, resolving within 16 weeks.

Poster Di Giminiani IPVS