Category Archives: Straw

Can tail damage outbreaks in the pig be predicted by behavioural change?

Vestbjerg Larsen, M.L., Andersen, H.M-L, Pedersen, L.J. 2016. Can tail damage outbreaks in the pig be predicted by behavioural change? The Veterinary Journal 209: 50-56.


Tail biting, resulting in outbreaks of tail damage in pigs, is a multifactorial welfare and economic problem which is usually partly prevented through tail docking. According to European Union legislation, tail docking is not allowed on a routine basis; thus there is a need for alternative preventive methods. One strategy is the surveillance of the pigs’ behaviour for known preceding indicators of tail damage, which makes it possible to predict a tail damage outbreak and prevent it in proper time. This review discusses the existing literature on behavioural changes observed prior to a tail damage outbreak. Behaviours found to change prior to an outbreak include increased activity level, increased performance of enrichment object manipulation, and a changed proportion of tail posture with more tails between the legs. Monitoring these types of behaviours is also discussed for the purpose of developing an automatic warning system for tail damage outbreaks, with activity level showing promising results for being monitored automatically. Encouraging results have been found so far for the development of an automatic warning system; however, there is a need for further investigation and development, starting with the description of the temporal development of the predictive behaviour in relation to tail damage outbreaks.

Tail postures
Tail postures
Pigs resting on straw
Pigs resting on straw

See also the related editorial:

Zonderland, J.J. and Zonderland, M.A., 2016. Behavioural change by pig producers is the key factor in raising pigs with intact tails (Editorial). The Veterinary Journal.

Re­search: How do Finnish pro­du­cers deal with long-tailed pigs?

Tail biting is a common and serious welfare problem in pig production, causing large economical losses. Tail docking is performed routinely in most EU countries to reduce the tail biting risk. However, tail docking is painful, and does not prevent tail biting totally. In Finland, tail docking is forbidden. New research shows that most Finnish producers would not raise tail docked pigs if it were possible.

Professor Anna Valros led a project asking with a web-survey from the Finnish farmers how they manage to raise pigs without tail docking. Respondents scored feeding-related issues to be most important for prevention of tail biting, identifying and removing the biting pig as most important intervention measures, and straw as the most important manipulable material when preventing tail biting. Tail biting was not perceived as a serious problem by over 70% of the respondents, even though docking is not allowed, and was reported to occur close to a level which was also considered acceptable by the respondents. Most respondents did not think it is probable they would raise tail docked pigs if it were possible, but about 21 % probably would.

These results are important for trying to reduce the risk of tail biting, and subsequently the need for tail docking on an international level.

Results are published in Porcine health management – journal.

More in­form­a­tion

professor Anna Valros, anna.valros(at)

tel. +358-29-4157400

Managing undocked pigs – on-farm prevention of tail biting and attitudes towards tail biting and docking,

Anna Valros, Camilla Munsterhjelm, Laura Hänninen, Tiina Kauppinen, Mari Heinonen, Porcine Health Management 2016

Strategies to reduce the risk of tail biting in pigs managed on slatted floors

By Jen-Yun (author)

A 4-year project of “Strategies to reduce the risk of tail biting in pigs managed on slatted floors” has started. It is a collaboration between Teagasc, SRUC and the University of Edinburgh.
Below is a poster on the project presented in the Teagasc Pig Farmers’ Conference 2015.
The project will aim to explore ways to reduce tail-biting on slatted floor systems where straw is not available by environmental enrichment and nutritional strategies.
The enrichments used at the moment are compressed straw and different wood types.
Later the project will also investigate the effects of various lengths of tails, measures to predict tail-biting outbreaks and methods to interfere effectively.
The project will be supervised by Dr Keelin O’Driscoll (Teagasc), Dr Rick D’Eath (SRUC), Dr Dale Sandercock (SRUC), and Prof Natalie Waran (University of Edinburgh).
Dr Amy Haigh is the postdoctoral researcher working together on this project in Teagasc, and Dr Laura Boyle and Dr Edgar Garcia Manzanilla are also the collaborating researchers in Teagasc. I (Jen-Yun) am the PhD student on this project.
fwd uk jy291015 entail poster - JC 28102015c

How much straw is enough?

Jensen, M.B., Herskin, M, Forkman, B, Pedersen, L.J., 2015. Effect of increasing amounts of straw on pigs’ explorative behaviour. Applied Animal Behaviour Science 171, 58–63.


  • We investigated the effect of straw amount on pigs’ time spent manipulating straw.
  • We investigated the effect of straw amount on pigs’ simultaneous straw manipulation.
  • Increasing straw from 10 to 430 g/pig/day increased both measures.
  • Increasing straw above approx. 250 g did not significantly increase the behaviour further.


According to European legislation, pigs must have permanent access to sufficient quantity of material to enable manipulation activities. However, few studies have quantified how much straw is needed to fulfil the requirements of growing pigs. We investigated the effect of increasing amount of straw on pigs’ manipulation of the straw, and hypothesised that after a certain point increasing straw amount will no longer increase oral manipulation further. From 30 to 80 kg live weight, pigs were housed in 90 groups of 18 pigs in pens (5.48 m × 2.48 m) with partly slatted concrete floor and daily provided with fresh uncut straw onto the solid part of the floor. Experimental treatments were 10, 80, 150, 220, 290, 360, 430 or 500 g straw per pig and day. At 40 and 80 kg live weight, the time spent in oral manipulation of the straw by three focal pigs per pen (large, medium and small sized) were recorded along with the percentage of pigs manipulating straw simultaneously. This was recorded in three 1-h intervals (1 h before and 1 h after straw allocation in the morning, as well as from 17 to 18 h in the afternoon). With increasing quantity of straw provided, we found a curvilinear (P < 0.01) increase in the time spent in oral manipulation of the straw. Smaller pigs spent more time manipulating straw than larger and medium sized pigs (367, 274 and 252 s/h for small, medium and large sized pigs, respectively; P < 0.001), and pigs spent more time manipulating straw at 40 kg than 80 kg live weight (356 vs. 250 s/h; P < 0.001). At both live weights, pigs spent most time manipulating straw during the hour after allocation of straw. Similar effects of increasing amounts of straw were found for the percentage of pigs engaged in simultaneous manipulation of the straw. Post hoc analyses were applied to estimate the point, after which additional straw did not increase manipulation of straw any further. For the time spent manipulating straw the estimated change point was 253 (approx. 95% confidence limits (CL) 148–358) g straw per pig and day. For the number of pigs simultaneously manipulating straw the change point was 248 (CL 191–304) g straw per pig and day. These results show that increasing the quantity of straw from minimal to approximately 250 g per pig and day increased the time spent in oral manipulation of the straw, as well as the occurrence of simultaneous straw manipulation.
Hence, data from the current experiment identified 250 g straw per pig per day as the amount of straw where a further increase in straw provision did not further increase neither time spent on oral manipulation of straw, nor the percentage of pigs simultaneously manipulating straw. This suggests that, within the current housing system and using this criterion, this amount of straw may be the biological turning point for increasing oral manipulation of straw.

Soundbites Pig Welfare Conference: 1. Introduction

On 29 – 30 April 2015 Danish Minister for Food, Agriculture and Fisheries, Dan Jørgensen hosted an international conference “Improving Pig Welfare – what are the ways forward?“.

During the two-day conference, top academics, experts and political stakeholders from around the world debated and worked to prepare the way forward in improving pig welfare in Europe and ultimately in the world. Ministers from the Netherlands, Germany and Sweden participated.

Below you find ‘soundbites’ from the conference, all more or less related to the subjects of study in the FareWellDock project. This is part 1. Parts 2-5 are other blog posts on this website.

It is truly remarkable that we have been able to gather almost four hundred participants to discuss the ways forward for pig welfare; some are joining us from as far away as the state of Iowa, USA, and Australia
Dan Jørgensen, Danish Minister for Food, Agriculture and Fisheries

fwd PWConf DK Minists IMG_1817c
Left to right: Dan Jørgensen, Minister for Food, Agriculture and Fisheries, DK. Sharon Dijksma, Minister for Agriculture, NL. Sven-Erik Bucht, Minister for Rural Affairs, SE. Christian Schmidt, Federal Minister of Food and Agriculture, DE.

At the conference a position paper was signed by
Christian Schmidt, Federal Minister of Food and Agriculture, DE
Sven-Erik Bucht, Minister for Rural Affairs, SE
Dan Jørgensen, Minister for Food, Agriculture and Fisheries, DK
Sharon Dijksma, Minister for Agriculture, NL

The position paper, final version(PDF)

Video of signing

Dan Jørgensen
Dan Jørgensen, Danish Minister for Food, Agriculture and Fisheries

Soundbites Pig Welfare Conference: 2. Presentations

On 29 – 30 April 2015 Danish Minister for Food, Agriculture and Fisheries, Dan Jørgensen hosted an international conference “Improving Pig Welfare – what are the ways forward?“.

During the two-day conference, top academics, experts and political stakeholders from around the world debated and worked to prepare the way forward in improving pig welfare in Europe and ultimately in the world.

Below you find ‘soundbites’ from conference presentations, all more or less related to the subjects of study in the FareWellDock project.

The Welfare Challenges Facing The Pig Sector
Peter Stevenson, Chief Policy Advisor of Compassion in World Farming, UK
Interview (video):
We have created a society where farmers’ margins are so low that they often have no choice but to have very low welfare (P. Stevenson)
We need to find a way in which we can make moving to higher welfare economically viable (P. Stevenson)
The EU should protect farmers from low welfare imports (P. Stevenson)
Most pigs in EU are given no enrichment or ineffective objects such as chains. … Plastic chewing sticks & balls are not effective enrichment (P. Stevenson)
An intact curly tail may well be the single most important animal-based welfare indicator in finishing pigs (EFSA update 2011, cited by P. Stevenson).
The average benefit of raising uncastrated pigs is around €5 per pig due to better feed conversion (EC, 2013, cited by P. Stevenson)
Consumers can drive animal welfare improvements – Don’t keep them in the dark (P. Stevenson).

Could Animal Production Become a Profession?
David Fraser, Professor, University of British Columbia, Canada
Interview (video):
Could pig producers function more like professionals and less like an industry? Professionals set their own standards. (D. Fraser)
The best common people are the agricultural population, so that it is possible to introduce democracy as well as other forms of constitution where the multitide lives by agriculture or by pasturing cattle. Aristotle, “Politics” (cited by D. Fraser).
In the past half century, animal agriculture in the U.S. has been taken over by corporations, turning family farms into factory farms (Farm Sanctuary, 2009, cited by D. Fraser).
Farm animal health levels: Piglet deaths: 0-50%; bursitis: 0-83%; sow mortality: 0-20%; dairy cow lameness 0-85%; broiler lameness: 0-90% (D. Fraser).
Animal welfare reforms have been modeled on worker welfare legislation that regulated the physical environment and exposure time in factories (D. Fraser).
Shifting animal production toward a professional model is a more promising approach to improving animal welfare and maintaining public trust in animal producers (D. Fraser).

Assessment and Alleviation of Pain in Pig Production
Sandra Edwards, Professor, Newcastle University, UK

Sandra Edwards
Sandra Edwards, Professor, Newcastle University, UK

Interview (video):
We need a very strong ethical justification for continuing farm-management procedures which are painful to animals, and look very actively for ways to reduce their necessity (S. Edwards)
Is castration necessary? Not all countries now think so (Backus et al., 2014), but sometimes it may be (S. Edwards)
What links castration, tail docking and gastric ulcers in pigs? Pain (S. Edwards)
Tail docking: Historically (and often currently): A surgical procedure carried out on young piglets with no pain relief (S. Edwards)
Does Tail docking Cause Pain? Many farmers believe not (or only insignificant) (S. Edwards)
30% of finishing pigs and 50% of culled sows have gastric sulcers (score >6). Gastric ulcers are acutely painful in humans. (S. Edwards)
Conclusion: The occurrence of pain compromises animal welfare
– It must be actively addressed.
– “Suppress, Substitute, Soothe”
(S. Edwards)
A reliable method for on-farm pain assessment is needed (S. Edwards)

Neonatal Piglet Mortality in Relation to Sow Farrowing Environment
Lene Juul Pedersen, Senior Researcher, Aarhus University, DK

Lene Juul Pedersen
Lene Juul Pedersen, Senior Researcher, Aarhus University, DK

Interview (video):
Genetic selection for increased littersize in Danish pig production has resulted in problems with piglet mortality that need to be solved, either by changing the breeding goal (to heavier piglets) and/or intensified piglet care (L.J. Pedersen).

Increased piglet mortality is not an innate problem of farrowing pens where sows can freely more around (L.J. Pedersen).
Piglets are born in a thermally insufficient environment (L.J. Pedersen).

Animal welfare in organic pig production
Jan Tind Sørensen, Professor, Aarhus University, DK
Interview (video):
Organic pig production does well on naturalness, welfare perception and low antibiotics use, but needs to solve problems with piglet mortality, endoparasites and castration (J.T. Sørensen).
Scientists cannot solve animal welfare. Politicians either. We need to collaborate to improve pig welfare (J.T. Sørensen).
Lameness prevalense in organic sow herds is higher during summer (Knage-Rasmussen et al 2014, cited by J.T. Sørensen).
High piglet mortality in organic pig production (Sørensen & Pedersen 2013, cited by J.T. Sørensen)
Organic pigs may be more resistant to Salmonella infections
(Bonde & Sørensen 2012, cited by J.T. Sørensen)

The Intelligent Pig Barn
Anders Ringgaard Kristensen, Professor, University of Copenhagen, DK
Interview (video):
Sensor technology is one of the ways forward in pig production (A.R. Kirstensen)
The intelligent pig barn – PigIT – Welfare problems considered: diarrhea, fouling and tail biting (A.R. Kirstensen).

The Danish Pig Welfare Action Plan
Per Henriksen, CVO, Danish Veterinary and Food Administration, DK

The use of animal welfare indicators
Jeremy Marchant-Forde, Research Animal Scientist, USDA-ARS, USA
Interview (video):
Scientists in the EU interact more with policymakers, while the US has closer links with producers (J. Marchant-Forde)
From 2005 to 2050 the global demand for meat will raise: poultry from 82 to 181M tonnes, beef from 64 to 106M, and pork from 100M to 143M tonnes (43%) (J. Marchant-Forde).

The Danish Animal Welfare Index Project
Björn Forkman, Professor, University of Copenhagen, DK
Interview (video):
The Danish Animal Welfare Index is animal-based, compares welfare across years and is based on a definition of welfare in terms of feelings (B. Forkman)
The Danish pig welfare conference showed an astonishing interest in pig welfare (B. Forkman).
“Happy pigs are dirty” (B. Forkman)

Ethical Meat Production & Consumer Response
Athanasios Krystallis Krontalis, Professor, Aarhus University, DK
Interview (video):
What people believe, sometimes is irrevant to the way they behave (A.K. Krontalis)

The social desirability effect implies that we tend to stay on the safe side, hiding what we really believe about something and simply reproducing stereotypes. So people have difficulty saying I don’t care about animal welfare (A.K. Krontalis).
It will take a lot of effort to reveal the real opinions of people generally [regarding animal welfare] (A.K. Krontalis).
29.149 food products launched with the claim “ethical” on their description (top-10 categories, all European countries) (Mintel Gnpd, Apr. 2013 cited by A.K. Krontalis).
Around 4,000 new food product launches with the term “Animal welfare” in their description. Mintel Gnpd, Apr. 2013 (cited by A.K. Krontalis).
People with weak attitudes to pig production eat somewhat more pork (A.K. Krontalis).
Not eating pork at all is not related to being critical to pork production (A.K. Krontalis).
consumers seek more information about production methods to make informed choices (Harper & Henson, 2001, cited by A.K. Krontalis)
In a EU survey (2005) consumers stated they are very rarely or never able to identify meat products from sustainable production methods (cited by A.K. Krontalis)
Ethical meat can be achieved by:
* Optimization of current production (consumer-driven)
* Development of new (technology-driven) production (i.e. in-vitro or insect-based), with questionable social acceptance potential (A.K. Krontalis).

Good welfare is good business
Jeremy Cooper, CEO, Freedom Food and Kate Parkes, Senior Scientific Officer, RSPCA, UK
Good welfare is good business (J. Cooper, CEO Freedom Food)
Freedom Food: > 3.5k members, 1 billion terrestrial farm animals, > 2k labelled products, almost 1/3 of UK pigs, 50% of UK eggs, > 70% of Scottish salmon (J. Cooper)

The effects of stockperson education and training on farm animal welfare
Paul Hemsworth, Professor, University of Melbourne, Australia
Attitudes tend to direct our behaviour or, at least, our intended behaviour (P. Hemsworth).
The best way to predict how stockpeople will interact with their animals is by knowing what their attitude is toward the activity itself (P. Hemsworth).
To target ‘stockmanship’ both technical and behavioural training of stockpeople are necessary! (P. Hemsworth).

Soundbites Pig Welfare Conference: 4. Posters

On 29 – 30 April 2015 Denmark hosted an international conference “Improving Pig Welfare – what are the ways forward?“.

Below you find ‘soundbites’ from posters presented at the the conference, all more or less related to the subjects of study in the FareWellDock project.

Do increasing amounts of straw increase growing pigs’ oral manipulation of straw?
Margit Bak Jensen, Mette S. Herskin, Björn Forkman, Lene J. Pedersen
Pigs were provided with various amounts of unchopped straw (10-500 gr/pig/day) to determine the amount of straw where additional provision did not further increase pigs’ exploratory behaviour.
Increasing the straw amount from 10 to 360 g straw per pig per day increased the time pigs spent in oral manipulation of straw markedly, while increasing the straw amount above 430 g straw per pig per day had no additional effect .
Approximately 400 g long straw per pig per day maximizes straw‐directed behaviour in partly slatted concrete floor (0.7 m2/pig)

Providing various amounts of straw (10-500 gr/pig/day) showed that oral manipulation of straw increases steadily up to 360 g straw/p/d. (M. Bak-Jensen et al.)

Increasing amounts of straw increase growing pigs’ production and healthLene J. Pedersen, Mette S. Herskin, Björn Forkman, Henrik Elvang Jensen, Margit B. Jensen
Aim: To quantify the amount of straw needed to achieve health and production effects, we investigated the effect of straw amount on the prevalence of gastric ulcers and production parameters.
Animals & housing: In both experiments pigs were housed in groups of 18 per pen, with partly slatted concrete floor (0.7 m2/pig) and fed a commercial dry feed for ad libitum intake.
Conclusion: The average daily gain (ADG) increased by 8±17 g/day for every extra 100 g straw added daily (P<0.001) resulting in 42 g higher ADG at 500 compared to 10 g straw provided. The feed conversion ratio was not affected by amounts of straw. The proportion of pigs with ulcerations was reduced by permanent access to straw (7 vs. 33%; P<0.05). Based on these results, production and health parameters were improved by increasing amounts of straw to pigs kept in conventional pens.

More straw improves production (ADG) and health (ulceration) parameters of pigs significantly (L.J. Pedersen et al.)

Tail biters may have a relatively high innate immune status (Ursinus et al.)

Straw provided to growing/finishing pigs resulted in a lower prevalence of tail lesions at slaughter (Dippel et al.)
The SchwIP management tool for tail biting in fattening pigs: a comprehensive approach for a complex problem (Dippel et al.)
Farm specific reports with causal explanations facilitate farmer engagement and knowledge transfer (Dippel et al.)

Tail lesions on carcasses of Irish slaughter pigs in relation to producer association with advisory services
N. van Staaveren, D. L. Teixeira, A. Hanlon and L. A. Boyle
The high prevalence of moderate tail lesions in a large proportion of batches of slaughter pigs suggests that chronic tail manipulation is a widespread problem. The large variation between batches indicates that there is good scope for improvement in the housing and management of pigs to reduce this behaviour on Irish farms. Given the economic and welfare implications of even moderate tail lesions it would benefit producers to receive information from the factory on such lesions recorded during meat inspection. This could help inform farm management plans and enable intervention before the behaviour escalates into tail biting.
The high prevalence of moderate tail lesions in a large proportion of batches of IE slaughter pigs suggests that chronic tail manipulation is a widespread problem (Van Staaveren et al.).
The large variation in tail biting between batches indicates that there is good scope for improvement in the housing and management of pigs to reduce this behaviour.
It would benefit pig producers to receive information about tail lesions recorded during meat inspection. This could help inform farm management and enable intervention before the behaviour escalates into tail biting (Van Staaveren et al.).

Experiences with Intact Tails in Well-Managed Conventional Herds
H.P. Lahrmann, T. Jensen, E. Damsted
Even in well-managed herds in average one out of two pigs is at risk of getting a tail lesion between 7-85 kg (Lahrmann et al., pilot study in DK).

Straw Use and Prevention of Tail Biting in Undocked Pigs – a Survey of Housing and Management Routines in Swedish Pig Farms
Stefan Gunnarsson, Beth Young and Rebecka Westin
The Swedish farmers reported limited problems with tail biting in finishing pigs. In nurseries tail biting was rarely observed.
Straw was provided to the pigs more or less daily.
Distribution of straw caused no problems with the manure system in 58% of the nurseries and in 81% of the finishing units (Gunnarsson et al.).

The Effect of an Enriched Environment on Biting Behavior and Performance of Finishing Pigs with Intact Tails
A. Bulens, S. Van Beirendonck, J. Van Thielen, N. Buys, B. Driessen
Pigs performed better in pens enriched with hanging toy, straw blocks and hiding wall: pigs had higher body weight at 90 kg and at 120kg, and showed less frustration and less tail manipulation. (Bulens et al.)

Curly Tails: the Dutch Approach
Marion Kluivers, Carola van der Peet, Anita Hoofs, Nienke Dirx, Nanda Ursinus, Liesbeth Bolhuis, Geert van der Peet
Dutch Curly Tails project aims at closing the gap between science and practice, and relieving the anxiety and scepticism about keeping pigs with long tails in current systems.
During the first year researchers and animal caretakers developed a mutual understanding that enabled putting scientific knowledge into practice (Kluivers et al.)
Costs and labour of keeping pigs with intact tails should not be underestimated (Kluivers et al.)
Biting behaviour can already start in the farrowing unit (Kluivers et al.)
Coaching, creating trust, transferring knowledge are essential in the process towards keeping pigs with long intact tails (Kluivers et al.)

How to solve a conflict without getting into a fight? Space for conflict resolution should not be regarded as an unnecessary luxury (Camerlink et al.)

Rat race to pigs without tail biting problems

Success is not certain but if you do nothing, failure is” Paul Ulasien
April 8 2015, written by Dr Nanda Ursinus, Adaptation Physiology Group, Wageningen University, The Netherlands

Damaging biting behaviours such as tail biting expressed by pigs is a huge problem in husbandry systems as it reflects and causes severe health and welfare problems, and economic losses. Many organisations world-wide focus on preventing and reducing these unwanted behaviours and so does Wageningen University and Research Centre, the Netherlands. During the Paris meeting of the Farewelldock-team (April 8 2015), a number of past, present and (possibly) future projects in which the  Adaptation Physiology Group of Wageningen University is involved, were presented that incorporate the problem of tail biting in pigs. In this blog two of the projects will be introduced: 1. A PhD trajectory entitled ‘A tale too long for a tail too short: Identification of characteristics in pigs related to tail biting and other oral manipulations directed at conspecifics’; 2. A project based on the Dalfsen Declaration: ‘Curly tails, the Dutch approach’.

A tale too long for a tail too short

Identification of characteristics in pigs related to tail biting and other oral manipulations directed at conspecifics

fwc blog NU phd tale too long 220415

In 2010 Nanda Ursinus started her PhD trajectory and had as main aim to identify biological characteristics of barren and enriched housed pigs that relate to their tendency to develop these damaging oral manipulative behaviours. The project was supervised by Professor Bas Kemp and Dr Liesbeth Bolhuis of the Adaptation Physiology Group, and Dr Kees van Reenen of Wageningen UR Livestock Research. In October 2014 the project finished by defending the thesis in front of an international committee.

The project showed that tail biting behaviour in intensively kept piglets with undocked tails can start as early as the lactation period leading to small tail wounds (± 10% of 480 piglets) observed at time of weaning (i.e. 4 weeks of age). Tail damage was largely prevented by providing straw-bedding, but tail wounds were not fully eliminated (1 pig out of 240 pigs was removed due to a tail wound) (Ursinus et al. 2014 Appl Anim Behav Sci 156:22-36). As straw-bedding is not suitable in many intensive pig husbandry systems, the use of jute sacks as enrichment device was explored. In partly docked gilts, jute sacks were able to reduce the presence of tail wounds five-fold and reduced the occurrence of damaging biting behaviours up to 50%. Furthermore, jute sacks tended to reduce damage to the sows’ tail inflicted by piglets (Ursinus et al. 2014 J Anim Sci 92:5193-5202). Post-weaning, tail biting pens could be predicted by an increased activity and increased levels of pig and pen-directed (e.g. jute sack usage) oral manipulative behaviours (Ursinus et al. 2014 Appl Anim Behav Sci 156:22-36; Camerlink et al. 2015 Behav Genet 45:117-126). Displaying tail biting behaviour by individual pigs is often temporary and consequently inconsistent over time; once a tail biter is not always a tail biter (Ursinus et al. 2014 Appl Anim Behav Sci 156:22-36). There seems to be one exception to this rule: gilts that were identified as high-tail biters during the rearing phase, were identified as high-tail biters during the nursery phase as well (Ursinus et al. 2014 J Anim Sci 92:5193-5202). This suggests that obsessive tail biters (as previously described by Taylor et al. 2010 VET J 186:137–147) may be more consistent in displaying tail biting behaviour than other types of tail biting behaviour. The main hazard in this is that obsessive tail biters are only occasionally present on farms and consequently but not surprisingly, it was hard to identify individual behavioural predictors of tail biting pigs. However, tail biters were likely to stem from a litter with a relatively high level of tail biting behaviour (Ursinus et al. 2014 Appl Anim Behav Sci 156:22-36). Additionally, in a spin-off project with piglets (n=160) that received a jute sack for three days (starting at 15 days of age), individual jute sack manipulation (i.e. nosing, chewing and rooting) turned out to be promising in terms of predicting biting behaviours (mainly directed at other body parts than the tail or ears) at 12 weeks of age (in preparation). We also studied pig personality a bit closer; although there are indications that tail biters would be active copers during stressful situations, our study did not find consistent evidence for that. However, our results suggested a higher level of fearfulness expressed during a novel object test in tail biting pigs. This finding was accompanied with lower blood platelet serotonin levels (i.e. a neurotransmitter involved in for instance mood) in tail biting pigs (Ursinus et al. 2014 PloS One 9:e107040). In a previous study, we also found signs that blood platelet serotonin and serotonin activity in the right hippocampus were related to a pig’s fearfulness (Ursinus et al. 2013 Physiol Behav 118:88–96). Our findings perfectly matches literature about mental disorders in humans and behavioural abnormalities in other animal species (e.g. feather pecking in laying hens). Tryptophan (i.e. the precursor of serotonin) is involved in many biological processes, also in for instance the most important production parameter in pigs: growth. Both phenotypic and genetic production parameters pointed in the direction of an association with (tail) biting behaviours in gilts (Ursinus et al. J Anim Sci 92:5193-5202) implying that pigs are searching for something with a nutritional value, possibly tryptophan. Although tail biting behaviour is not as consistently displayed in individual animals as previously expected and the environment seems to play a large (or even the largest) role in the development of damaging biting behaviours, the results show that also the role of genetics cannot be ignored. Up until now it is difficult to capture the level of expressed tail biting in direct breeding values. However, indirect breeding values or ‘indirect genetic effects’ have been associated with tail damage. Pigs differ in their heritable effect on their group mates’ growth and pigs with a positive effect on their group mates’ growth were found to cause less tail damage (Camerlink et al. 2015 Behav Genet 45:117-126). Tail biting behaviour in pigs thus seems to be caused by a variety of temporary states and more stable traits that influence their motivation to display foraging and exploratory behaviours. Preventing and reducing such unwanted behaviours requires a joint effort of science, industry and society to optimize housing conditions, feeding, management and breeding of pigs.

For more information you can contact Nanda Ursinus (Nanda . ursinus @ wur . nl or Nanda . ursinus @ gmail . com) or Liesbeth Bolhuis (Liesbeth . bolhuis @ wur . nl). This project was funded by the Dutch Ministry of Economic Affairs, and it was a collaboration with the Dutch ‘Sociable Swine’ project. In the Sociable Swine project four PhD trajectories were finished:

  1. Sociable swine: Indirect genetic effects on growth rate and their effects on behaviour and production of pigs in different environments. Irene Camerlink, 2014.
  2. (Em)pathetic pigs? The impact of social interactions on welfare, health and productivity. Inonge Reimert, 2014.
  3. Sociable Swine: Prospects of indirect genetic effects for the improvement of productivity, welfare and quality. Naomi Duijvestein, 2014.
  4. Engaging Society in Pig Research: A multi-stakeholder approach to enhance animal welfare in pig production. Marianne Benard, 2014.


fwc blog NU phd Sociable swine 220415fwc blog NU phd Empathic pigs 220415

Sociable swine (Duijvestein)Engaging society

 Dalfsen Declaration

Curly tails, the Dutch approach

In 2012, a group of Dutch stakeholders in the pig farming sector joined forces in an attempt to find ways to reduce the need for tail docking in pigs kept in the Netherlands. Therefore they developed and signed a Declaration, now called the ‘Dalfsen Declaration’. Declaration partners involve the industry (Dutch Federation for Agriculture and Horticulture (LTO), Dutch union of Pig Producers (NVV), Coppens Animal Feed, Topigs (now Topigs Norsvin), Royal Netherlands Veterinary Organisation (KNMvD) and Vion Food Group), an NGO (Dutch Society for the Protection of Animals), and a research centre (Wageningen University and Research Centre: Department of Animal Sciences and Wageningen UR Livestock Research). The ambition of this stakeholder-group was supported by the Dutch Ministry of Economic Affairs and several other parties in the pig chain. During the course of time 3 routes are followed: 1. A demonstration project, 2. Creating a network of Dutch front runners, and 3. Stepwise increasing the tail length.

The demonstration project started end 2013 at Pig Innovation Centre Sterksel (VIC Sterksel), the Netherlands, and likely ends in December 2015. The project allows animal caretakers to practice with a number of enrichment materials and to learn understanding the behaviour and especially the tail posture of pigs. Enrichment materials used were sometimes rather complex (such as straw or grass silage) and at other times less complex (such as a rope or straw pellets). The materials were provided on the floor, at the walls, or hung from the ceiling and eventually need to be valued by the caretakers as easily applicable in Dutch (intensive) husbandry systems. Enrichment is used both as a preventive and curative measure. As many pig farmers are in search of especially curative measures it is highly important to assess if enrichment materials are suitable in ending or at least reducing the severity of ongoing tail biting outbreaks. In 2015, a start-up meeting was organised with a group of enthusiastic front runners that keep pigs with long tails or are willing to try increasing the length of the tails of (some of) their pigs. During this meeting farmers gave insight in what they need (on their own farm) in order to be able to keep pigs with longer tails. These farmers will be guided and their actions will be monitored. The main ambition is to stepwise increase the length of pig tails in the Netherlands by gradually docking less. Collaboration with neighbouring countries is desired and therefore first steps are made by the Dutch Ministry of Economic Affairs to assess if (the Ministries of) Germany and Denmark share the vision of the Dalfsen Declaration Partners and are willing to join forces as well.

Contact person of the Dutch Curly tails project is Geert van der Peet (geert . vanderpeet @ wur . nl).

Pigs rooting on the floor

Saving the pig tail

Anna Valros and Mari Heinonen published a paper called “Save the pig tail” in Porcine Health Management.


Tail biting is a common problem in modern pig production and has a negative impact on both animal welfare and economic result of the farm. Tail biting risk is increased by management and housing practices that fail to meet the basic needs of pigs. Tail docking is commonly used to reduce the risk of tail biting, but tail docking in itself is a welfare problem, as it causes pain to the pigs, and facilitates suboptimal production methods from a welfare point-of-view. When evaluating the cost and benefit of tail docking, it is important to consider negative impacts of both tail docking and tail biting. It is also essential to realize that even though 100% of the pigs are normally docked, only a minority will end up bitten, even in the worst case. In addition, data suggests that tail biting can be managed to an acceptable level even without tail docking, by correcting the production system to better meet the basic needs of the pigs.

Valros, A., M. Heinonen, 2015. Save the pig tail. Porcine Health Management 2015 1:2.

Straw reduces piglet mortality at farrowing related to starvation and stillbirth

This post presents the highlights and abstract of a paper by Westin et al.:

Westin, R., Holmgren, N., Hultgren, J., Ortman, K., Linder, K., Algers, B. In press. Post-mortem findings and piglet mortality in relation to strategic use of straw at farrowing. Prev. Vet. Med.


• Post-mortem examination was performed in 798 piglets from 363 litters.
• The major post-mortem findings were starvation (34%) and crushing (28%).
• Fewer piglets starved to death in STRAW compared to CONTROL-litters.
• Strategic use of straw reduced the number of stillborn piglets by 27%.


Piglet survival is the outcome of complex interactions between the sow, the piglet and
their environment. In order to facilitate nest-building and to provide a suitable environment  for the newborn piglets, a strategic method to supply loose housed sows with large  quantities of straw at farrowing has been developed by Swedish piglet-producing farmers.  The objectives of this cohort study were to use post-mortem findings to assess the causes of death and to quantify the effect of a large quantity of straw provided before farrowing compared to limited small daily amounts on stillbirths, post-mortem findings in piglets dying within 5 days after birth and the pre-weaning mortality. On each of four commercial piglet-producing farms in South-West Sweden, one batch of sows was studied during two consecutive lactations. At inclusion, sows were randomly assigned to two treatment groups, and sows remaining in the batch during the next lactation switched treatment group. In the STRAW group (n = 181 litters) sows were provided with 15–20 kg of chopped straw 2 days prior to the calculated date of farrowing. Sows in the CONTROL group (n = 182 litters) received 0.5–1 kg of chopped straw on a daily basis plus about 2 kg for nest-building when the stockperson judged the sow to be about to farrow. After onset of farrowing, additionally 1–2 kg was given. Post-mortem examination was performed in all piglets that died within 5 days after birth (n = 798). The three major post-mortem findings were starvation (34%) crushing by the sow (28%), and enteritis (24%). In conclusion, strategic use of large quantities of straw reduced the number of stillborn piglets per litter by 27% (p = 0.007). Under the conditions studied, the pre-weaning mortality of liveborn piglets was not affected by treatment; however, the distribution of post-mortem findings differed with fewer piglets dying due to starvation and more due to crushing and enteritis in STRAW litters.

Newborn piglet
Newborn piglet (Photo by Rebecka Westin)