Dossier

Tail biting and tail docking

Routine tail docking, although banned in the EU, is persistent in conventional pig farming as it reduces the risk of tail biting. Tail biting is an abnormal behaviour of pigs related to suboptimal housing and/or management involving stress and reduced welfare. It is associated with an inability to perform species-specific behaviours related to exploration (enrichment) and searching for food (rooting).

Source photo: © WUR

This dossier aims to help Competent Authorities and other stakeholders with issues related to tail docking and tail biting of pigs. The dossier is updated periodically by the EURCAW-Pigs team. The text is meant to support Competent Authorities, and is not legally binding.

It is based on the so-called Staff Working Document, published by the Commission in 2016, which accompanies the Commission Recommendation (EU) 2016/336 which describes measures to reduce the need for tail-docking. The following six key factors should be checked when carrying out a risk assessment of the incidence of tail-biting: Environmental enrichment; Climate; Health status; Competition over resources; Diet; and Pen structure and cleanliness.

Each EURCAW-Pigs dossier is divided in the following 5 items: 'Legislation', ‘Welfare indicators’, ‘knowledge’, 'Inspiring examples', and 'Training courses'.

_{Source photo:}_©WUR

The legal requirements related to tail docking can be found in two Council Directives, and in two supporting documents from the Commission.

Key publications

Council Directive 98/58/EC, EC, 1998 concerning the protection of animals kept for farming purposes lays down the basic principle that pigs should be offered an adequate level of welfare.
Council Directive 2008/120/EC, EC, 2008 elaborates on this and sets out specific rules on the protection of pigs.
Commission Recommendation (EU) 2016/336, EC, 2016 describes measures to reduce the need for tail-docking.
In accordance with the recommendation, best practices to reduce tail biting are suggested in a Staff Working Document, EC, 2016 which is not legally binding.

Council Directive 2008/120/EC states: "Neither tail-docking nor reduction of corner teeth must be carried out routinely but only where there is evidence that injuries to sows’ teats or to other pigs’ ears or tails have occurred. Before carrying out these procedures, other measures shall be taken to prevent tail biting and other vices, taking into account environment and stocking densities. For this reason inadequate environmental conditions or management systems must be changed." {Annex I, Chapter I, point 8}.

_{Source phot}_o:_©FLI

Tail biting is an abnormal behaviour, involving the biting of pigs in the tails of their penmates, resulting in tail injuries. It is a response to boredom, insufficient stimulation, and frustration related to negative environmental and management factors that can increase pigs’ stress levels. Tail biting is a multi-factorial problem, filling up a ‘cumulative risk bucket’. At a certain point, the bucket overflows, and tail biting starts.

Why bother about tail biting?

Tail biting causes pain, and indicates compromised animal welfare in both biter and victim pigs. It leads to lower carcass weight and condemned or trimmed carcasses. This, in turn, means economic losses for pig farmers. Tail docking, as a remedy to reduce tail biting, also causes pain, fear and frustration. Tail docking may only be carried out if there is evidence of previous tail lesions, and only after all known risk factors have been addressed.

Stages of tail biting

Tail biting typically occurs in different stages:

Pre-injury tail chewing is difficult to detect based on inspection of the tails, but early signs include hanging/clamped tails, tail wagging, hairless tails (there should be a clear plume of hair at the tip of the tail), and restlessness;
In the damaging stage, biting is more forceful, blood is present from wounded tails and the behaviour escalates within the group.
Later on, more severe injuries are visible and larger parts of the area around the tail may have been eaten away: at this stage it is called cannibalism.

Guidance

The Commission has developed the Commission Staff Working Document on how to implement the Commission Recommendation and best practices to reduce the need for tail-docking. Moreover, the Commission’s leaflet Cutting the need for tail docking, available in 8 languages, recommends actions to take for each of the six key (risk) factors: Environmental enrichment; Climate; Health status; Competition over resources; Diet; and Pen structure and cleanliness.

Welfare indicators for inspections for assessment of (the risks for) tail biting are given in the next section.

_{Source photo:}_{©Bracke et al. 2012}

The results of recently published studies indicate that slaughter findings may play an important role for a retrospective assessment of certain aspects of animal welfare on farm. However, currently tail lesions recorded at the abattoir in the context of meat inspections do not allow valid conclusions on the occurrence of tail biting on farm (see ‘Show more’).

Iceberg indicator

It is difficult to distinguish whether fresh tail lesions occurred on farm, during the transport to the abattoir or within the lairage pens. However, beside the limitations, assessing tail damage at the abattoir potentially can serve as an iceberg indicator for on farm welfare and health if (a) functioning feedback systems to farmers and Competent Authorities are available and (b) standardized assessments of tail lesions at the slaughterhouse are implemented.

Automated methods for recording tail lesions and lengths at the abattoir have been successfully developed and tested in research pilot projects. However, there is still a need for further improvements of the algorithms and technology before these systems can be put into practice.

For further reading on background, existing practices in the EU, results, and future developments, see EURCAW-Pigs’ short review “Existing practices and current research on feedback of tail slaughter findings”.

_{Source photo: ©FLI, A. Schubbert}

The current conditions in which weaned pigs are kept are the most important in relation to the development of tail biting behaviour. Evidence for associations between management and housing during suckling and tail biting behaviour is scarce and contradictory (see ‘Show more’).

Early life risk factors

EURCAW-Pigs gives a short overview of the current knowledge on potential early life risk factors and their impact on tail biting behaviour in later life in the short review “Management of unweaned piglets”.

Tail biting is a multifactorial problem and different aspects can contribute to the expression of tail biting. The suckling period is a very sensitive phase in piglet production. Piglets, especially from large litters, are highly challenged in early life. Risk factors such as undernutrition, social stress due to competition, and crossfostering are suggested to increase tail biting behaviour in later life. These factors mostly relate to hyper-prolific sows with large litter sizes.

Further research is needed to investigate possible effects of thermal comfort, air quality, health status, acute stress and the housing environment to prevent the expression of tail biting in later life.

_{Source photo: ©AU, Cecilie Kobek-Kjeldager}

Welfare indicators can be used to monitor animal welfare on-farm and check compliance with legislation regarding tail docking and tail biting. Tail biting may be assessed on-farm, or post mortem at the slaughterhouse after scalding. Indicators to assess the risks for tail biting cover the six key risk-factor areas. In EURCAW-Pigs’ indicator factsheets, several important welfare indicators are described, by suggesting an inspection and scoring method, and describing the underlying welfare concern and legal requirements.

How to assess tail biting?

On-farm

In a first step you may estimate the length of the tail. Is it intact or shortened? A shortened tail can result from tail docking or from tail biting.
In a second step you may assess minor or severe tail lesions. Severe lesions are recognized by wounds or necrosis.

How to assess the risk for tail biting?

Enrichment - Absence of sufficient and adequate enrichment materials is the largest risk factor for tail biting. Indicators that can be checked to ensure that pigs benefit from proper enrichment materials are:

Climate - Indicator to assess risks for poor thermal comfort and air quality.

Pig fouling

Health and fitness - Specific indicators of herd health are:

Competition over resources - The provision of sufficient resources can be confirmed by an indicator
such as:

Skin lesions

Diet - The provision of an adequate and balanced diet can be confirmed by indicators such as:

Pen structure/cleanliness - The provision of adequate pen structures can be confirmed by parameters such as:

Cleanliness/fouling of the pigs

_{Source photo: ©WUR}

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Active stall fatteners: Adequate enrichment - Smart4Life

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First aid for tail biting Adequate enrichment - BZL

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Preventing tail biting: see all inspiring examples

In collaboration with national training bodies and national reference centers on animal welfare, EURCAW-Pigs develops training guides for the different welfare topics as standards for national training in EU Member States.

Learning goals

On the subject tail biting and tail docking:

Knowledge about the intention of the EU-legislation (Protection of animals kept for farming purposes, Minimum standards for protection of pigs, Minimum standards for the protection of pigs as regards measures to reduce the need for tail-docking)
Updated knowledge about the biology and behavioural needs of pigs in relation to exploratory behaviour, foraging behaviour, social behaviour and abnormal behaviours and needs related to supply of water and feed as well as climate and pen environment.
Knowledge about the six key factors identified as risk factors for tail biting: Enrichment materials, climate, health status, competition over resources, diet and pen structure/cleanliness
Knowledge about indicators to assess tail biting and to assess the risks for tail biting covering the six key risk-factor areas.
Tools for calibration and practical training in calibration using the indicators.
Guidelines for an aligned selection of pens/ pigs for inspection under different conditions.
Knowledge on measures to improve welfare within the six risk areas and indicators to asses improvements.
Knowledge about challenges in relation to communication with farmers during inspection.

Inspection-driven welfare improvement

Additionally, EURCAW-Pigs provides examples of training plans and materials used in different Member States in English, to the extent possible, and training suggestions for improvement of communication skills and ways to support inspection-driven welfare improvement. This is presented on the training overview page.