Hennovation partner Thea van Niekerk reported on a couple of interesting project results in Resource (article in Dutch):
Alpacas may protect free-range laying hens from birds of prey.
A custom-made trolley can substantially improve the welfare of spent laying hens.
Pecking blocks were tested in the Netherlands (cementblocks used for construction appeared best; see flyer).
Dutch_farmers are learning to live without beak trimming
Poultry World, Aug 22, 2018
Beak treatments will formally be banned in the Netherlands from next year, but the market has moved ahead of legislation. Poultry World discovers how farms are managing the change.
From the beginning of September, members of the Netherlands’ largest egg assurance scheme, IKB EI, will not be permitted to keep hens with treated beaks.
This also includes infrared beak trimming. To this end, Avined decided to anticipate market demands as much as possible.
The German KAT (Association for Controlled Alternative Animal Husbandry) monitoring system has already prohibited the restocking of hens with trimmed beaks with effect from 1 January 2017.
COST action GroupHouseNet Stakeholder Meeting
June 27th 2018
Schedule (Local time in Turkey: CET +1),
Webstreamed session:
09:00-9:05 Brief introduction to the Action and meeting, Action Chair Andrew M. Janczak
09:05-9:10 Introduction from the organiser, Sezen Ozkan
09:15-9:45 Challenges and possible solutions related to damaging behaviour in laying hens, Mia Fernyhough, RSPCA
09:50-10:20 Research on risk factors and prevention of damaging behaviour in laying hens, Elske de Haas, WUR
10:20-10:45 Break
10:50-11:20 Tail biting and actions to prevent tail biting in the EU, Copa Cogeca, Miguel
Angel Higuera, Director ANPROGAPOR, Madrid
11:25-11:55 European Commission project to reduce systematic tail-docking of piglets in
Member States, Desmond Maguire, European Commission, DG Health and Food Safety
How to join the webstream:
When research meets farming to lift welfare (article in Poultry World, dd 12-6-2018).
The EU-funded Hennovation project was an exercise in bringing egg farmers together with researchers to develop practical ways to improve welfare, as Tony McDougal discovers.
Researchers have partnered with farmers to draw up practical new measures for improving the health and welfare of farmed poultry.
The 2 ½ year EU-funded Hennovation project, which ended this autumn, has been finding ways to introduce practice-led innovation in sustainable animal welfare through the development of innovation networks.
Read more at the Poultry World website.
A new international research group (COST ACTION) has started to address the problem of keel bone damage in laying hens.
The KeelBoneDamage COST Action will provide the laying hen industry with the innovations in breeding, nutrition, and management necessary to resolve the problem of keel bone damage in order to meet the high standards of welfare and productivity demanded by the European community. The extremely high frequency and severity of keel bone damage represents one of the greatest welfare problems facing the industry, a position held by leading authorities of animal welfare, including the UK`s Farm Animal Welfare Committee (FAWC) and European Food Safety Authority (EFSA). The Action seeks to provide a platform for collaboration on the causes of keel bone damage and solutions to reduce their severity and frequency. Through coordination of a variety of mediums including meetings, training schools and scientific exchanges, our network brings a diverse mix of disciplines together to facilitate novel and trans-disciplinary discussions that will lead to an accelerated rate of discovery and achievements. Participants come from a variety of stakeholder groups including academic scientists, policy makers, non-governmental organizations, and industry. The diversity of these partners will ensure that developments are directed into tangible outputs that improve animal welfare and farm productivity.
You can find more on its website. The website also contains some practical stakeholder information about records, recommendations and an online tool.
This is post 1. “Introduction” of:
Towards a common conceptual framework and illustrative model for feather pecking in poultry and tail biting in pigs – Connecting science to solutions
Marc B.M. Brackea, T. Bas Rodenburgb, Herman M. Vermeera, Thea G.C.M. van Niekerka
a Wageningen Livestock Research
b Wageningen University, Dept. of behavioural ecology
This is one of 8 blog posts under the heading of: “Towards a common conceptual framework and illustrative model for feather pecking in poultry and tail biting in pigs – Connecting science to solutions”. It contains the following sections/posts:
The entire text (8 posts) can be downloaded as one pdf here.
Feather pecking (fp) in poultry and tail biting (tb) in pigs are among the most persistent animal-welfare problems associated with intensive livestock farming. Both problems have been studied and reviewed extensively (e.g. fp: (Rodenburg et al., 2008; Nicol et al., 2013; Rodenburg et al., 2013); tb: (Schrøder-Petersen and Simonsen, 2001; Bracke et al., 2004a; EFSA, 2007b; Taylor et al., 2010; D’Eath et al., 2014; Valros, 2017)). Legislation and policy initiatives have been discouraging the continued performance of routine mutilations (beak treatment and tail docking for fp and tb respectively). However, both poultry and pig farmers generally find it difficult to stop mutilations and prevent and/or treat these injurious behaviours in intensive farming systems. Comparing fp and tb may help address these problems. However, few papers have compared the two forms of abnormal behaviour in detail. One notable exception is the fairly recent Open-Access publication by Brunberg et al. (2016). These authors discussed similarities and differences between fp and tb, and presented a general model which looks somewhat like an envelope. This publication is written for a scientific audience, and it is not easy to read for farmers and others interested in solving fp/tb such as vets, other farm advisors and NGOs. Also the ‘envelope-shaped’ model presented by Brunberg et al. (2016) is not as appealing as we would (ideally) like it to be. It mainly says that by nature both pigs and poultry are omnivorous generalists that have (had to) become production specialists via genetic selection and rearing in large-scale intensive systems applying a one-size-fits-all principle. According to Brunberg et al. both the physical and social environment (‘where you are’ and ‘who is with you’), together with animal-related factors (‘who you are’) determines ‘what you become’ in terms of fp or tb, i.e. a performer (pecker/biter), victim/receiver or a neutral animal. The authors also hypothesise that the gut-microbiota-brain axis may play a crucial role which should be investigated further. This is in accordance with the common view that fp and tb are multifactorial problems associated with the substantial discrepancy between the natural and the commercial environment resulting in a (seriously) deprived foraging (and/or feeding) motivation that eventually leads to fp/tb (and worse, i.e. cannibalism, if not curtailed adequately).
It is not entirely clear, however, why the model (figure) in Brunberg et al. (2016) should look like an envelope. When looking a bit more closely at the figure, the model appears to encompass everything (the animal, its history and its entire, physical and social, environment). Only upon more careful examination and in particular when reading the text itself do the further ramifications underlying the model become more clear. Since we feel the text may be rather inaccessible for practical application in problem solving, one objective of these blog posts, therefore, is to compare this model to other models, esp. those developed in our own organisation (Wageningen University & Research), in order to see if we can better highlight the available knowledge that should be used to (eventually help) solve the problem in practice. To this end we have also tried to make the information presented by Brunberg et al. (2016) more accessible, and we supplemented it with our personal expertise on fp/tb. It is important to emphasise, however, that the primary aim of this publication is to improve on the available conceptual frameworks to facilitate practical understanding of fp and tb so as to support solving the problem in the future. We do not, however, aim to present a tool box or cook book for solving fp/tb.
This was blog post nr. 1 under the heading of: “Towards a common conceptual framework and illustrative model for feather pecking in poultry and tail biting in pigs – Connecting science to solutions”. It contains the following sections/posts:
The entire text (8 posts) can be downloaded as one pdf here.
Acknowledgements
These blog posts have been made possible by the Hennovation project (HORIZON 2020 ISIB-02-2014 project, Grant no. 652638).
This is post 2 on “Terminology” of:
Towards a common conceptual framework and illustrative model for feather pecking in poultry and tail biting in pigs – Connecting science to solutions
Marc B.M. Brackea, T. Bas Rodenburgb, Herman M. Vermeera, Thea G.C.M. van Niekerka
a Wageningen Livestock Research
b Wageningen University, Dept. of behavioural ecology
This is one of 8 blog posts under the heading of: “Towards a common conceptual framework and illustrative model for feather pecking in poultry and tail biting in pigs – Connecting science to solutions”. It contains the following sections/posts:
The entire text (8 posts) can be downloaded as one pdf here.
In the next posts we will summarise similarities and differences between feather pecking (fp) in laying hens and tail biting (tb) in pigs, taking Brunberg et al (2016) as a starting point. We will also characterise the different models that have been proposed before on fp/tb. Building on this we will argue why we think that fp/tb may/should be regarded as a medical/mental disorder, provided the medical framework maintains an evolutionary and scientific perspective on fp/tb.
This post aims to characterise the underlying concepts and criteria, so as to illustrate that giving crisp definitions may not be as easy as it may seem to be at first sight.
Note: We will use the label ‘fp/tb’ in the remainder of these related posts to refer to the communal problem. It is difficult to provide an overarching term for fp and tb together. Most existing terms are too wide: Abnormal behaviour, injurious behaviour and harmful-social behaviour, e.g. because there are other forms of abnormal behaviour and because there are other forms of injurious behaviours like aggression (e.g. vulva-biting in sows) and abrasive behaviours (injuries resulting from making contact to flooring or pen fittings; cf fin injuries in farmed fish (Noble et al., 2012; Stien et al., 2013; Pettersen et al., 2014; Folkedal et al., 2016)).
An outbreak of injurious fp/tb requires a specification of the start and end point, i.c. presence of injuries. Here, again, the observer may play a significant role: the detection of injuries depends e.g. on the inspection frequency and quality (e.g. method & expertise) of the observer. The observer also plays a role in so-called early-detection and in decision-making as to when and what treatment is to be started to counteract an on-going outbreak.
It should also be emphasized that fp/tb is a process, where different types of animals are involved. In order to start, one ‘neutral’ animal must become an actor (pecker/biter) showing fp/tb behaviour towards a victim/receiver resulting in a fp/tb wound. When the outbreak escalates more and more individuals become involved and/or wounds become progressively severe, potentially leading to the death of the victim (such that the fp/tb may at some point be called ‘cannibalism’). Wounds may also get infected, thereby aggravating the impact on productivity and welfare. Some animals in a fp/tb pen may not get involved. These may be labelled ‘neutrals’. In addition, Brunberg et al. (2016) use the term ‘controls’ for animals in neighbouring pens which are not affected by fp/tb. These different types of individuals involves are not fixed over time. E.g. both neutrals and controls are labels that may changes over time (Daigle et al., 2015), i.e. animals that were neutrals/controls today, may become actors or victims tomorrow, and individuals may be both actor and victim at some point in time (or even at the same time). When an outbreak ends, both actors and victims may return to being ‘neutrals’, even though it is generally recognised that the probability of recurrence is much bigger in groups that have previously experienced fp/tb problems, as if the ‘set points’ of such animals have changed irreversibly. Because of this rather irreversible state-change it is important to differentiate between prevention, what is done to prevent an outbreak, and curative treatment, what is done to stop an outbreak that has occurred.
A final term used in these posts is the word ‘model’, by which we primarily mean a figure intended to explain fp/tb. Ideally, the model should not only illustrate the mechanism and the types of individuals involved, and where/how it goes wrong (e.g. that fp/tb is a multifactorial problem), but also provide answers to the other 3 why questions (evolution, function, ontogeny). Ideally, also the model should explain anomalies (i.e. apparently ‘strange’ facts) and generate testable predictions. The ideal model should also be effective in communicating what is the (e.g. welfare or production) problem associated with fp/tb and provide suggestions regarding prevention and/or treatment. Also, a model is better if it uses a stronger, more intuitively appealing metaphor, such that it is easily remembered, not only by scientists, but also by other stakeholders, i.c. farmers, their advisors, and NGOs (see e.g. cartoons at http://www.featherwel.org/). However, besides addressing all of these aspects, a good model should not be complex, but rather explain fp/tb in the most parsimonious way possible.
This was blog post nr. 2 under the heading of: “Towards a common conceptual framework and illustrative model for feather pecking in poultry and tail biting in pigs – Connecting science to solutions”. It contains the following sections/posts:
The entire text (8 posts) can be downloaded as one pdf here.
Acknowledgements
These blog posts have been made possible by the Hennovation project (HORIZON 2020 ISIB-02-2014 project, Grant no. 652638).
This is post 3 on “Overview of main similarities and differences between feather pecking and tail biting” of:
Towards a common conceptual framework and illustrative model for feather pecking in poultry and tail biting in pigs – Connecting science to solutions
Marc B.M. Brackea, T. Bas Rodenburgb, Herman M. Vermeera, Thea G.C.M. van Niekerka
a Wageningen Livestock Research
b Wageningen University, Dept. of behavioural ecology
This is one of 8 blog posts under the heading of: “Towards a common conceptual framework and illustrative model for feather pecking in poultry and tail biting in pigs – Connecting science to solutions”. It contains the following sections/posts:
The entire text (8 posts) can be downloaded as one pdf here.
Table 1 shows an overview of similarities and differences between feather pecking (fp) in poultry (i.c. laying hens) and tail biting (tb) in pigs (i.c. weaned and growing/fattening pigs).
Table 1 is based primarily on Brunberg et al. (2016) and supplemented with our own (esp. MB and TvN) knowledge about fp and tb (also as presented on the henhub website www.henhub.eu). The table is intended to summarise the most relevant similarities and differences between fp (in hens) and tb (in pigs), and thus support decision making in dealing with fp/tb in practice.
The key risk in fp/tb is the fact that both laying hens and pigs are originally omnivorous generalists that have been become production specialists in feed intake and food conversion in intensive farming conditions. The motivation for fp/tb relates to a frustrated foraging need, which is modulated by a whole array of different risk factors, hence resulting in this multifactorial welfare issue. In addition to similarities the table also identifies a number of differences between fp in layers and tb in pigs, e.g. we don’t have genetically selected lines for tail biting comparable to the high and low fp lines in poultry. Hence, an experimental model to study tb in more detail is currently largely lacking (though pigs selected for social breeding value (high indirect genetic effects for growth) showed considerably less ear biting, tail damage, aggression and enrichment manipulation (Camerlink et al., 2015), and may thus in principle be suited to be used to study tb experimentally in more detail).
The table may perhaps be improved upon further by specifying relationships between the items specified as risk factors (in the left column) and the different responses identified in the process of fp/tb (in the right column; cf (Fraser, 1987a)).
Another suggestion relates to the many risk factors that may hamper practical problem solving. While scientific experiments necessarily vary only a few risk factors in order to reliably examine which factors may affect fp/tb, a tentative suggestion for solving the multifactorial fp/tb problem could be to try to formulate multifactorial solutions. This may be esp. relevant when monofactorial solutions fail to solve the problem. However, an important drawback of this approach is that it may essentially remain unclear which factors are accountable for any (positive or negative) results. When a multifactorial approach is working, it may be possible to tease out in subsequent research the relative contribution of the different risk factors. When it doesn’t work, that may be the end of the road for that particular type of farming (given the constraints imposed).
Table 1. Comparing risk factors and animal responses related to feather pecking (fp) in poultry (laying hens) and tail biting (tb) in pigs, taking Brunberg et al. (2016) as a starting point, supplemented with own author expertise (marked as *). Common risk factors (similar across species, specified between brackets when ‘unknown’) are followed by notable differences between Hens and Pigs (specified on the next lines). Black characters: risk increasing factors; green: risk decreasing factors (benefits); red (in the column ‘risk factors’): particularly welfare-reducing risk factors. ‘No’: means that the opposite reduced fp/tb.; behav.: behaviour; envir.: environment; decr.: decreased; incr.: increased; HFP: high fp line/breed; LFP: low fp line; TIM: tail-in-mouth; w: weeks; d: days; mo: months. The cells in column ‘Responses’ are not directly (horizontally) related to the risk factors. Responses are stacked: more positive behaviours are presented at the bottom; worst (form of escalation, i.e. cannibalism) is shown on top. Responses are related to ‘type of animal’ (victim, actor, neutral) (with welfare aspects specified at the level of the type-of-animal label). Poor welfare responses are shown in red (in the column ‘responses’). See the text for a more detailed description of how to read the table.
| Type of factor | Risk factors (Multifactorial, related to the type of factor, i.e. environment-, group- & animal based) | Responses (behav., physiology, pathology & welfare, related to type of animal, i.e. victim, actor, neutral) | Type of animal |
| Envir.-based | Modern large-scale specialised farms | Victim: fear, pain (during outbreak), stress, sickness (during treatment, recovery) | Victim |
| Barren pen (no proper foraging material, straw), large discrepancy between intensive farming envir. and the natural envir./envir. of evolutionary adaptation | Cannibalism | ||
| (Partly) slatted floor Hens: (Litter) Pigs: Concrete |
(Wound) infection | ||
| Indoors* Hens: Range (may provide foraging opportunities and reduce stocking density) Pigs: – (Outdoor area may provide rooting substrate (soil), fibre (pasture), but not necessarily) |
Production loss (reduced growth) Hens: Egg laying (reproduction) Pigs: Growth (production) |
||
| One size fits all (food, climate*) | |||
| Standardised feed, optimised for average individual (vs indiv. needs); perhaps probiotics may treat fp/tb Hens: – Pigs: No phase feeding; decr. feeding frequency predicted tb outbreaks 9 w later; tb victims made more feeder visits 2-5w prior to tb |
Appearance Hens: Deteriorating feather cover Pigs: Tucked tails |
||
| Feed changes and ‘hiccups‘ in providing feed (unpredictable frustration) | Decreased tryptophan, serotonin levels | ||
| Feed type; Reduced feeding time, not ground, concentrated feed, less fibre Hens: Pellets give more fp than fine ground feed; no mash/pecking materials; high E diet; no feathers in diet (acting as fibre, incr. feed passage) Pigs: Contradictory results (liquid/pellets/meal) but straw reduces tb & is consumed |
(Fp/tb) Wound(s) Hens: Esp. tail, body (not back of head) Pigs: Tail (possibly ears, flanks, legs) |
||
| Protein, mineral (NaCl) deficiency; supra-nutritional NaCl may alleviate fp/tb Hens: Deficiency of crude protein, amino acids, minerals (Na, Ca) Pigs: Nutritional imbalance incr. tb |
|||
| Feeder space, feed competition (bite/peck to get access to feed) | Salivation (pH incr.; alleviate peptic ulcers) | ||
| Rearing conditions (both poor rearing conditions and a backdrop from enriched rearing conditions to deprived conditions later in life) Hens: Absence of litter around 5w, high stocking densities, rearing on wire floor Pigs: More piglets/stockperson, fostering, no straw in farrowing pen, reduced feeder space during rearing gives more tb later in life; multi-litter rearing decr. manipulative behav.; providing straw during rearing and then depriving pigs of straw later is also considered a risk factor |
[Microbiota composition?] Hens: HFP has different microbiota composition than LFP; feather eating changes gut microbiota; Pigs: Unknown |
||
| (Pen size, pen design) Hens: (Large) Pigs: (Small) |
Escalation of tp/tb (outbreak) | ||
| Group-based (envir.- & animal based) | Group housing Hens: (Very) large groups (10-100.000 birds) Pigs: Small (~10 pigs) |
Arousal, restlessness, excitement (positive), fear & avoidance (negative). Hens: Cut feathers increased fp Pigs: Blood tail model (rope) increased (tail) biting behav. |
|
| High stocking density Hens: More fp in largest groups (15-120 birds) Pigs: (Not uniform results) |
Cognition, (social) learning, (synchronisation; copy-behaviour; stimulus enhancement) | ||
| Farm health status (any (major) stressor/immune suppressor probably) Hens: Vaccination (specific immune stimulation) when young may incr. fp as adults; LFP have better immunocompetence; e.g. E. Coli incr. severe fp Pigs: Better health status reduces tb; straw reduces infections |
Prevalence/intensity: Hens: Fp on 86% of UK flocks; SFP esp. when adult; fp up to 135 bouts/bird/hr; 3 severe pecks/min Pigs: Tb on 30-70% of farms; fanatic biters bite 11-25% of time |
||
| Mutilation (3 aspects are relevant: 1. Method used; 2. Amount of tissue removed; 3. Age of treatment; esp. 2nd aspects is relevant as risk factor)
Hens: Beak treatment (previous beak trimming (may remove larger/smaller part of the beak), now infrared beak treatment) (Note: In poultry, as it were the (future) actor is mutilated) |
Severe fp (SEP)/tb
Hens: – Pigs: Three types of (severe/injurious) tb: two-stage (starting with TIM), sudden forceful, and obsessive (fanatic) |
||
| Pigs: Tail docking (longer or shorter part of the tail) (Note: in pigs as it were the (future) receiver is mutilated by removing the tail) | Actor: (Excitement, pleasure [during outbreak], pain, stress [during treatment]) Hens: Pecker Pigs: Biter |
Actor, performer | |
| History of fp/tb (once an outbreak has occurred, the likelihood of another outbreak increases; animals are never the same again after an outbreak; (irreversibly) changed set points) | Object-direction: Hens: Towards feathers Pigs: Towards the tail |
||
| Animal-based | (Bred for) very high production-efficiency (genetics, breeds) (esp. genetic motivation of feed-related behav.; behavioural need to species-specific foraging behav); fp/tb has moderate heritability (~0.2) | Neutral (in same pen)/control (on other pen): Neutral as a biter in spe: boredom, frustration, behavioural deprivation, esp. of foraging motivation |
Neutral / control |
| Hens: (Eggs) Pigs: Lean meat; neutrals have different genetics |
Gentle manipulation Hens: Gentle fp is prevalent in young birds, decr. with age Pigs: Tail in mouth (TIM), |
||
| Domesticated 5-6000 years ago; bred in 50 years of intensive selection from foraging generalists (omnivorous (variable diet; need to explore)) to meat & egg producing specialists; fp/tb not selected against; tb&fp are correlated to production, but not in the same way | Pen-mate directed exploration Hens: (Deteriorated) plumage condition Pigs: Wet tails |
||
| Hens: Male peckers had higher body fat; female peckers had earlier onset of lay; HFP: Better growth, lower total egg mass, decr. feed efficiency Pigs: Lower backfat, lean tissue growth |
Consummatory behav.: Hens: Feather eating (more in HFP) Pigs: – |
||
| Being different Hens: Plumage colour (standing out from others; incidental pigmented birds were more often victims) Pigs: [Lame pigs get bitten] |
Object/substrate-directed exploration/foraging in accordance with nature, showing natural behav. (50-60% of time) Hens: Scratching, pecking Pigs: Rooting, biting |
||
| Personality Hens: Peckers appear more proactive, fearful (in open field), stress (cortisol shows variable results); more foraging & walking when young incr. fp as adults; HFP more active; mobility to get to the nestboxes (i.e. too calm birds are at risk for fp) Pigs: Low backtest responders showed less pen-mate manipulation; biters more sitting & kneeling 6d prior to tb; victims more posture changes 6 d prior to tb; tail posture (tucked) may predict tb 2-3d before outbreak |
|||
| Sex, probably females more active performers Hens: All females Pigs: Mixed/uni-sex; males receive more tb; uncastrated males are more likely to become fanatic biters (1 study) |
|||
| Age: Onset around sexual maturity (also then shifting nutritional needs) Hens: Adult (16-80wks); progesterone (& oestrogen) incr. up to 18w incr. fp; testosterone decr. fp; SFP ~20w in females, but not males Pigs: Young, prepubertal (<5-6mo); perhaps associated with teething* |
|||
| Body weight Hens: – Pigs: Biters are lighter; victims tend to be heavier before tb (later decr. growth) |
This was blog post nr. 3 under the heading of: “Towards a common conceptual framework and illustrative model for feather pecking in poultry and tail biting in pigs – Connecting science to solutions”. It contains the following sections/posts:
The entire text (8 posts) can be downloaded as one pdf here.
Acknowledgements
These blog posts have been made possible by the Hennovation project (HORIZON 2020 ISIB-02-2014 project, Grant no. 652638).
This is post 4 on “Farmer as a risk factor” of:
Towards a common conceptual framework and illustrative model for feather pecking in poultry and tail biting in pigs – Connecting science to solutions
Marc B.M. Brackea, T. Bas Rodenburgb, Herman M. Vermeera, Thea G.C.M. van Niekerka
a Wageningen Livestock Research
b Wageningen University, Dept. of behavioural ecology
This is one of 8 blog posts under the heading of: “Towards a common conceptual framework and illustrative model for feather pecking in poultry and tail biting in pigs – Connecting science to solutions”. It contains the following sections/posts:
The entire text (8 posts) can be downloaded as one pdf here.
Though not specified in Brunberg et al. (2016) human stakeholders, i.c. the farmer, may also be included in the description of feather pecking (fp)/tail biting (tb). Since the farmer must make management decisions (at many different levels), he/she will affect all other risk factors involved in fp/tb. In fact, it has been proposed that the farmer may be the most important risk factor (Van Dooren, 2013; Zonderland and Zonderland-Thomassen, 2016). Like the animals, farmers will be showing behavioural responses, and farmers may also experience welfare problems in case of fp/tb.
As is the case for the animal, what matters to the farmer is how (s)he perceives the problem (rather than what is the problem in ‘reality’ (Uexküll, 1909)). For example, laying hens living in a multilayer system (volière) may be perceived as having access to litter. However, what matters to welfare is how the animal perceives its environment, e.g. a hen living in the upper tiers may not have access to litter, thus live in an environment without litter (and thus be more prone to fp). Similarly, a farmer who believes that beak treatment/tail docking is painless (a false belief), or who has a strong aversion to pecking/biting wounds may not have the motivation required to (try to) end the practice of routine preventive mutilations. Thus what matters is how the problem is perceived. The farmer’s problem solving in case of fp/tb may be hampered by being ‘allergic’ (e.g. to wounded animals due) to fp/tb, and by being ‘lethargic’ (e.g. being unable to respond adequately when active treatment is called for when fp/tb starts). While the farmer has the end responsibility of how his animals are reared, other stakeholders also play a role, e.g. a farmer’s ability to deal with fp/tb may depend on other farmers (e.g. who are rearing his animals, or who ventilate opinions as to whether ending mutilations is (not) desirable), the market (e.g. the retailer who is buying his eggs/pigs), the government (issuing legislation and taking policy measures to simulate and/or discourage certain practices), and farm advisors (e.g. providing/withholding knowledge and support required to deal with the fp/tb problem). Table 2 lists main farmer-related risk factors and responses involved in fp/tb. Note: we have decided to incorporate the responses in the list of risk factors, because the way a farmer responds to fp/tb (prevention, treatment, early-detection) is itself part of the farm management.
Table 2. Farmer-related risk factors of feather pecking (fp) and tail biting (tb), and farmer-related responses related to the type of factor (environment-based; farmer-based, and response-based (1; curative treatment; 2: prevention; 3. early detection). Red: welfare reducing aspects.
| Farmer-related risk factors (management) & responses (prevention & treatment) | Type of factor |
| Economy, market | Environment-based |
| Legislation (and its enforcement), policies | |
| Social support/pressure, sector/chain image | |
| Fp/tb specific farm management regarding (timely/delayed) treatment: e.g. providing enrichment, identifying & resolving cause(s)/risk factor(s), isolation/removing actor and/or victim, dimming the lights (impaired vision), repellents, mutilation (as a treatment in untreated animals), monitoring (i.e. treatment evaluation). Pigs: teeth cutting (cf beak treatment in Hens: removing animal’s ‘equipment’ to do harm). |
Response [1] |
| Hens: spectacles (another form of impaired vision used in the past (before beak trimming was invented, to prevent accurate sight of feathers); culling of peckers (peckers may be identified by their pecking behaviour or perhaps by their relatively unaffected feather cover). | |
| Fp/tb specific farm management regarding prevention: e.g. mutilation, enrichment, climate, food, health care, monitoring (early detection) |
Response [2] |
| Fp/tb specific farm management regarding early detection: Hens: Reducing feather cover may indicate fp is starting Pigs: Tucked tails, wet tails (possibly reduced feeder visits; enhanced interest in enrichment materials) |
Response [3] |
| General farm management (quality; quantity) | Farmer-based |
| Knowledge, education | |
| Personality (reactive, proactive) | |
| Attitudes (towards animal welfare, etc.). |
This was blog post nr. 4 under the heading of: “Towards a common conceptual framework and illustrative model for feather pecking in poultry and tail biting in pigs – Connecting science to solutions”. It contains the following sections/posts:
The entire text (8 posts) can be downloaded as one pdf here.
Acknowledgements
These blog posts have been made possible by the Hennovation project (HORIZON 2020 ISIB-02-2014 project, Grant no. 652638).
This is post 5 on “Models” of:
Towards a common conceptual framework and illustrative model for feather pecking in poultry and tail biting in pigs – Connecting science to solutions
Marc B.M. Brackea, T. Bas Rodenburgb, Herman M. Vermeera, Thea G.C.M. van Niekerka
a Wageningen Livestock Research
b Wageningen University, Dept. of behavioural ecology
This is one of 8 blog posts under the heading of: “Towards a common conceptual framework and illustrative model for feather pecking in poultry and tail biting in pigs – Connecting science to solutions”. It contains the following sections/posts:
The entire text (8 posts) can be downloaded as one pdf here.
Table 3 shows a list of various models/figures that have been proposed to clarify feather pecking (fp)/tail biting (tb), including the recent model proposed by Brunberg et al. (2016). Our focus here was to compare models, esp. models originating from Wageningen University Research, in search for potential improvements. Not all models have been included in Table 3. For example, Valros and Heinonen (2015) propose a modified bucket model where the bucket is filled with acute and/or chronic stressors (cf also Valros (2017)).
Since copy-rights are a problem for representing models, below a selection is given of models for which Wageningen UR (already) has the copy-rights. Other models can be obtained via the cited references or the internet. E.g. an example of the psychohydraulic model (Lorenz, 1950; 1978) can be found here.
Figure 7.3 below shows the tail biting (tb) model by Zonderland (2010a) (Fig. 7.3, p. 138).
The conceptual framework for tb originating from Bracke (2008) (reprinted in (Bracke, 2017)) is shown in Figure 1 below. This model was designed to construct the RICHPIG model (decision support system) to assess/calculate the welfare value of enrichment materials for pigs.
Figure 1. Schematic representation of the conceptual framework for assessing environmental enrichment for pigs. EMat: Enrichment material; AMI: animal-material interactions; I: Istwert, the environment as perceived by the animal; S: Sollwert, set point or norm (modified homeostatic model after Wiepkema (1987) and (Anonymous, 2001)). (Figure from Bracke (2008), permission granted by UFAW) (reprinted from (Bracke, 2017)).
Citation from Bracke (2017) relating the model to the principle of communicating vessels:
“Progressive feedback loops in the framework indicate that the animal’s welfare is good when proper enrichment satisfies the pigs’ need to explore and forage. When the enrichment is deficient, the animals will redirect their attention and show pen- and pen-mate directed behaviour. Note that this may imply a mechanism resembling the principle of communicating vessels (connected containers filled with liquid; see Wikipedia (2016c)). In accordance with this principle pigs may distribute their (motivation for) exploratory behaviour (the liquid) depending on the quality of the manipulable ‘materials’ available to them (cf Bracke et al. (2012)). Eventually, an outbreak of tail biting may occur, potentially evoking a positive feedback loop (an escalating outbreak) leading to cannibalism when no ‘proper enrichment’ is provided buffering and/or eliminating the (primary) cause/stressor.” (End of citation).
In the communicating-vessels model, for which we found some empirical evidence in pigs (Bracke, 2017), vessel size may change due to animal-properties like genetics; but also e.g. enrichment-based and other risk factors.
In the case of fp in poultry, in a classic paper Newberry et al. (2007) questioned the assumption of communicating vessels underlying the hypothesis that fp is redirected foraging behaviour as proposed earlier by Blokhuis (1986). Newberry et al. (2007) showed that birds with high levels of ground pecking as chicks were more likely to develop high levels of fp as adults compared to low ground pecking chicks. However, the high ground pecking chicks also continued to show high levels of ground pecking as adults, shedding doubt on the theory that fp would replace ground pecking.
Under ‘mechanism’ Van Niekerk (2015) presents both a balance model and a tipping-bucket model for fp (see also Van Niekerk (In prep.)). The bucket model was modified from a tb model originally proposed by Vermeer in Bracke et al. (2012). The main problem of the tipping-bucket model is that it suggests that fp/tb cannot stop, cannot be made undone (or perhaps only via an external ‘force’, e.g. a farmer taking adequate measures to correct the problem). Perhaps the model could be improved, e.g. by making a tumbler-type tipping bucket, such that it can be emptied, and then may restore its original position. However, this revised tumbler model would still be deficient in that post fp/tb set points are not the same as before (as a tumbler would suggest). Another option might be a series of buckets. Once tipped, the next bucket could stay down, with the next bucket being smaller, such that the next tipping point would be reached sooner, with preventive measures reducing the flow of water into the bucket. This would solve the issues just mentioned, but it would seem to be a somewhat ‘artificial’/non-parsimonious model.
Figure 2. Tipping-bucket model of feather pecking (Van Niekerk (2015); modified after Bracke et al. (2012)).
Figure 3. Balance model (Van Niekerk (2015), from http://www.henhub.eu/fp/mech/).
Perhaps the balance model could be modified to a balance between ‘fixed’ risk factors on the one scale and management (farmer effort) to reduce tb/fp risk on the other scale of the balance. However, the symmetry in disbalance suggested by the model does not seem to make sense: too much pressure on one side does not have the same effect as too much pressure on the other side. Also, fp/tb does not seem to be (totally) reversible: inducing fp/tb by removing a bit of enrichment cannot be undone by adding the same bit of enrichment (at least not shown). Also, to date no studies are available showing reversibility by adding other factors (e.g. inducing tb/fp by poor litter quality and then ‘treating’ this problem by adding e.g. better feed, etc.).
The next figure (Figure 4 below) shows a newly developed ‘face’ model aimed at incorporating the different types of animal involved (actor, victim, neutral), as well as emphasising the role of the farmer (as a kind of ‘actor’) in dealing with a fp/tb problem. The farmer is important for prevention and treatment of fp/tb. The emergence of an animal-actor is necessary to start fp/tb, but the responsiveness of the victim also plays a roll. For example, a victim may more or less effectively avoid becoming a victim and respond more or less in a way that leads to escalation of an outbreak. While a learning process may have transformed actors into individuals predisposed to show the abnormal fp/tb behaviour again at a later stage, similarly, at some point victims may show learned helplessness (which may also more or less permanently alter their behavioural predisposition).
Figure 4. New ‘face’ model of feather pecking (fp)/tail biting (tb), showing its multifactorial nature (‘left ear’), the role of different types of animal (actor & victim (‘eyes’), neutral (‘mouth’)), array of responses (‘right ear’), as well as the role of the farmer (‘nose’) in dealing with the problem. Both positive and negative feedback loops (‘glasses’ around the eyes of the face) are involved. Evolution and life history (‘hairs’) determine the set points of the individuals (animals and farmer). The comparators (‘pupils’ etc.) are (more or less) equivalent to welfare (smiley, balance, bucket and marble run) as indicated in the ‘necklace’ below the face. TIM: tail in mouth; OCTB: obsessive-compulsive tail biting; p.m.: pen mate; i.r.t.: in relation to. (Modified after (Bracke, 2017), and incorporating elements of the other models shown above, i.c. the balance and bucket models).
This was blog post nr. 5 under the heading of: “Towards a common conceptual framework and illustrative model for feather pecking in poultry and tail biting in pigs – Connecting science to solutions”. It contains the following sections/posts:
The entire text (8 posts) can be downloaded as one pdf here.
Acknowledgements
These blog posts have been made possible by the Hennovation project (HORIZON 2020 ISIB-02-2014 project, Grant no. 652638).