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Animal Welfare - Recent Reports and Comments

Animal Welfare vol 21 issue 4 Volume 21
Issue 4
November 2012

Electrical requirements for water-bath stunning of poultry

Although controlled-atmosphere systems are being increasingly used to induce unconsciousness in the slaughter of poultry, electrical water-bath systems are still widely used throughout the world to stun birds prior to slaughter. These involve suspension of the birds by their legs on a moving shackle line that conveys them to a water-bath into which their heads are immersed. The birds complete an electrical circuit between the water-bath and the shackle line, and the principle is that the current flow induces immediate loss of consciousness before they are bled, and such that they do not recover before death due to blood loss. These systems may be set so as to cause cardiac arrest also. The efficacy of these systems depends on the strength of the current, whether it is AC or DC, and the shape and frequency of the electrical waveform. Problems arise because the ideal parameters of the current for stunning may not be the ideal parameters from the meat quality point of view and also because the current that flows through each bird depends on how much flows through the other birds in the water-bath at the same time. Resistance varies between birds according to the quality of the contact their legs make with the shackles and many other factors.

There has been considerable research into electrical stunning of poultry but it has not been on such a scale as to provide a comprehensive description, or to allow robust predictions, about the efficacy of all the possible combinations of electrical variables (current, waveform, frequency and whether AC or DC) in inducing unconsciousness. There are gaps in knowledge in this field and a further problem is that it is possible that, in some circumstances, birds showing signs of being effectively stunned may not have been. Electro-encephalography (EEG) is the most reliable method for assessing unconsciousness but it cannot be applied in commercial practice.

The UK and Dutch Governments asked the European Commission (EC) to review regulations about electrical parameters. For example, the UK Government was concerned that high frequency currents (> 800 Hz) might cause immobilisation without unconsciousness and the Dutch Government was concerned that the regulations specify average water-bath currents instead of the minimum currents that must be delivered to each bird. The Animal Health and Welfare Panel of the European Food Standards Agency (EFSA) was therefore asked by the EC to review and make recommendations about the water-bath stunning of poultry.

The Panel's report was published in July 2012. It included 21 conclusions, the last of which were: “When water-bath stunning is used it is not possible to ensure that all birds are stunned” and “It may not be practical at the present time to measure EEG routinely in the abattoir. However, laboratory studies do show that current flow through individual birds at a specified frequency can be used with confidence to predict the EEG. Thus, the effectiveness of the stun can be assessed under abattoir conditions from accurate measurement of current flow through individual birds”.

Recommendations regarding policy and further research which follow from the conclusions of this EFSA review include that the EC regulation should specify minimum current for each bird and also the current type and the frequency and shape of the waveform, and that there should be further research into the correlation of EEG and practical measures of unconsciousness and insensibility. The final conclusion of the report is that: “Unless the problems described in this opinion for all existing water-bath stunning methods can be resolved, other stunning methods should be used”. There will be costs involved in addressing these matters and it seems reasonable that these should be met by the consumers for whom the poultry is produced.

Scientific Opinion on the Electrical Requirements for Water-Bath Stunning Equipment Applicable for Poultry 2012 A4, 80 pages. EFSA Panel on Animal Health and Welfare (AHAW). EFSA Journal 2012; 10(6): 2757. doi:10.2903/j.efsa.2012.2757. Available online at: http://www.efsa.europa.eu/en/efsajournal/pub/2757.htm.

JK Kirkwood,

OIE International Standards for Stunning and Killing of Farmed Fish for Human Consumption, 15th Edition, 2012

These standards, which form part of the OIE’s (World Organisation for Animal Health) recently updated Aquatic Animal Health Code, provide recommendations for the humane treatment of farmed fish at the time of stunning and killing. The recommendations are subdivided into: personnel; holding facilities; the unloading, transfer and loading of fish; and methods of stunning and killing. A summary table of the welfare issues associated with different stunning and killing methods is also provided.

The standards promote two overriding principles — that fish should be stunned before killing, and that equipment, parameters and methods used should be appropriate to the species of fish being stunned and killed.

The stunning and killing methods discussed are divided into mechanical (being percussion, spiking, coring and shooting) and electrical methods. Methods involving chilling, carbon dioxide narcosis, salt or ammonia baths, asphyxiation and exsanguination without stunning are deemed to result in poor welfare and are recommended against if mechanical or electrical methods are feasible.

These standards provide a sound basis upon which to build national or regional legislation. It may not be within the remit of these guidelines to provide specific recommendations (in the form of facts and figures) and, indeed, such detail is not included. However, this could be seen as a missed opportunity. Future revision of these standards could introduce more specific guidance; for example, maximum times for crowding, fasting and holding fish out of water.

Some of the recommendations also require clarification and consideration of their practicality. It is said that stunning should be verified by the lack of consciousness — is this for a sample of the harvest or for each individual fish? Although the ideal, the latter would be difficult to achieve when stunning and killing on a large scale, as may the requirement to re-stun any fish showing signs of regaining consciousness.

Another potential oversight is found where the recommendations state that fish should be killed following the use of potentially reversible percussive or electrical stunning: methods for achieving this are not provided.

Notwithstanding the lack of specific detail, the wholehearted adoption of the general principles included in these recommendations by the 178 member countries would greatly improve the welfare of farmed fish at stunning and killing around the world.

Welfare Aspects of Stunning and Killing of Farmed Fish for Human Consumption 2012 A4. Aquatic Animal Health Code, 15th Edition, 2012, Chapter 7.3. Available at: www.oie.int/en/international-standard-setting/aquatic-code/access-online/ .

N Williams,

A model for assessing animal welfare in pest control

Innumerable animals are killed or otherwise controlled as ‘pests’ around the world every year. In most cases, the animal welfare impacts of this control have been unknown. Where animal welfare has been considered, there has not been a consistent approach applied. This is despite a desire amongst practitioners and others to see animal welfare concerns addressed.

Driven by the consideration of this issue under the Australian Animal Welfare Strategy, a model for assessing animal welfare impacts in pest control has been developed with input from scientists, regulators and animal welfare, veterinary, pest animal control and livestock sector organisations. The model was first published in 2008. Since then, it has been used to assess the major pest control methods in both New Zealand (Fisher et al 2010) and Australia. This second edition brings together the Australian assessment and the model, revised in light of the assessment process.

The model lays out a two-stage scheme for assessing the animal welfare impacts of methods used to kill or manage animal pests. Part A examines the impact of a method on overall welfare and duration of this impact. Part B examines the intensity and duration of pain or distress caused by the killing technique (if applicable). The model takes account of impacts on the target animal only (the individual affected pest) and assumes best practice application of the method.

The assessment of a selection of pest control methods using the model was conducted by an expert panel using information from the scientific literature. The outcome is presented in a series of worksheets and figures showing method scores, with supporting evidence.

The model is intended to provide information for practitioners and regulators on the animal welfare impacts of methods, to encourage the use of more humane methods. It is also intended to highlight where more humane methods should be developed.

A Model for Assessing the Relative Humaneness of Pest Animal Control Methods, Second Edition 2011. Written by Sharp T and Saunders G, Australian Government Department of Agriculture, Fisheries and Forestry, Canberra, ACT. Available online and for download at: http://www.daff.gov.au/animal-plant-health/welfare/aaws/humaneness-of-pest-animal-control-methods. The full set of assessments is available at http://www.feral.org.au/animal-welfare/humaneness-assessment/.


Fisher P, Warburton B, Beausoleil N and Mellor DJ 2010 How humane are our pest control tools? (09-11326) MAF Biosecurity New Zealand Technical Paper No 2011/01. Ministry of Agriculture and Forestry: New Zealand. Available online: http://www.biosecurity.govt.nz/about-us/our-publications/technical-papers#how-humane-are-our-pest-control-tools

K Littin,
Ministry for Primary Industries,
New Zealand

The use of animal-based measures to assess the welfare of broilers

The Animal Health and Welfare (AHAW) Panel of the European Food Standards Agency (EFSA) has recently published a Scientific Opinion which lays out an independent view on the use of animal-based measures to assess the welfare of meat chickens. The report is divided into three main sections. The first outlines the background work that was undertaken for the Opinion, the second discusses the terms of reference given to EFSA by the European Commission, and the third considers how welfare assessment may be further developed when taking into account factors that affect animal welfare, measures used to assess it, and the links between them.

Animal-based measures seek to evaluate the welfare status of an animal directly and to encompass any impact that environmental and management factors may have. Essential attributes of animal-based measures are discussed within the report, such as validity (the accuracy of a measurement to correctly identify a specific welfare consequence, ie sensitivity and specificity) and robustness (the repeatability and reliability of an animal-based measure).

EFSA provides an array of possible animal-based measures that may be used to assess broiler welfare and the strongest animal-based measures on-farm are considered to be: panting, dehydration, lameness, culls on-farm, on-farm mortality, plumage cleanliness, and emaciation. When assessing welfare at the slaughterhouse during meat inspection, the prevalences of the following are considered to be appropriate: foot-pad dermatitis, hock burn, breast burns, breast blisters, emaciation, ascites, and dehydration.

It is not expected that all measures will be used in all situations; the intention is that the list of measures should act as a ‘toolbox’. EFSA states that the measures selected “will depend on which welfare outcomes (consequences) are to be assessed and the reason for wanting to assess them (eg whether part of a management/breeding strategy or to enforce legislation)”.

Various circumstances in which protocols for assessment of broiler welfare may be employed are listed, and include: by a manager of a farm to monitor management decisions; by an auditing or accreditation organisation to check that a farm satisfies the necessary criteria to be part of a quality assurance or labelling scheme; by farmers to check that their farm satisfies animal welfare requirements and to track changes as a result of alterations to management or environment; by a competent/responsible authority to check that a farm satisfies animal welfare requirements according to legislation, and evaluate effects in practice of changes in animal welfare legislation; by scientists during an experiment, so that their results can be compared with the results collected by other scientists.

The methodology and interpretation of the animal-based measures given is not described, and instead the reader is directed to other publications for guidance, eg Welfare Quality® protocols (further information available at: http://www.welfarequality.net). Additionally, EFSA notes that to maintain repeatability and reliability over time requires regular training of assessors to ‘recalibrate’ them to a reference standard. Other important considerations outlined include ensuring that in assessing the welfare of a flock, the sample of birds examined must be representative and of sufficient size.

A number of animal-based measures have been developed and are currently being used in commercial practice (eg automated detection and scoring of foot-pad dermatitis at slaughterhouses); however, others still require further work. In particular, EFSA notes that: “There are currently no animal-based measures to use as welfare-outcome indicators on-farm or in the slaughterhouse to assess the issues of pain, frustration, boredom and other positive and negative emotional states in the standard broiler. Research in this area is lacking”.

EFSA draws the report to a close with conclusions and recommendations for each of the four terms of reference. This Opinion is the latest in a growing series (similar reports were published in January 2012 for dairy cattle and pigs) following a request by the European Commission that EFSA review the use of animal-based measures to assess farm animal welfare. It is expected that similar Opinions will be published for other farmed species.

Scientific Opinion on the Use of Animal-Based Measures to Assess Welfare of Broilers 2012. A4, 74 pages. EFSA Panel on Animal Health and Welfare. EFSA Journal (2012); 10(7): 2274. doi: 10.2903/j.efsa.2012.2774.
Available online at: www.efsa.europa.eu/efsajournal.

E Carter,

New Zealand Code of Welfare for meat chickens

New Zealanders annually consume more chicken than any other meat and over 80 million birds are raised by around 160 poultry farmers every year to supply the domestic market. In an effort to ensure that the welfare needs of meat chickens are met, the National Animal Welfare Advisory Committee (NAWAC) has recently issued a new Code of Welfare: Animal Welfare (Meat Chickens) Code of Welfare 2012.

The Code covers all meat chickens raised for commercial production (both fully housed and those with access to outside areas), from in-shell chicks in the last half of development, to the catching of chickens ready for transport to the processing plant for slaughter. It does not cover the welfare of birds during transport or at slaughter; animal welfare during these times is protected by the Animal Welfare (Transport within New Zealand) Code of Welfare 2011 and the Animal Welfare (Commercial Slaughter) Code of Welfare 2010, respectively. Additionally, meat chicken breeder birds are not included within the scope of this Code.

Persons for whom this Code is intended are all those considered responsible for the welfare of meat chickens. In New Zealand, much of the poultry industry is vertically integrated and meat chicken hatcheries are owned by a small number of poultry processing companies, which also own the feed manufacturers. These companies contract out the rearing of birds, from one-day old to slaughter weight, to other people. The processing companies retain ownership of the birds and they therefore have an overarching responsibility for ensuring that the welfare needs of the chickens owned by them are met. Additionally, individuals responsible for the day-to-day care of meat chickens and any ‘person in charge’ at a particular point in time are also responsible for bird welfare.

The key areas considered by the Code are: Stockmanship; Food and Water; Shelter and Facilities; Providing for Behavioural Needs; Physical Handling; Disease and Injury Control; Hatchery Management; and Welfare Assurance System. Within these sections, a total of 15 minimum standards are provided, along with example indicators which may be used to show that a standard is being adhered to. Additionally, the majority of minimum standards are also followed by corresponding sections on recommended best practice, to encourage higher standards of welfare.

Also included within the Code is a list of interpretations and definitions of terms used, legislative requirements, and the titles of other Codes of Welfare, Codes of Recommendations and Minimum Standards, and other welfare Guidelines.

Animal Welfare (Meat Chickens) Code of Welfare 2012 July 2012. A4, 34 pages. National Animal Welfare Advisory Committee, Ministry of Agriculture and Forestry, New Zealand. ISBN: 978-0-478-38897-8 (print), ISBN: 978-0-478-38898-5 (online). The guidelines are available at the MPI’s website: http://www.mpi.govt.nz/biosecurity-animal-welfare/animal-welfare, or by emailing: animalwelfare@mpi.govt.nz.

E Carter,

Statistics of Scientific Procedures on living animals, Great Britain 2011

In the United Kingdom, the welfare of laboratory animals is protected by the Animals (Scientific Procedures) Act 1986. Part of the Act (Section 21[7]) requires the Secretary of State to publish annually information on the use of protected animals for experimental or other scientific purposes.

Figures have been collected detailing the number of scientific procedures for many years. The latest report to be published, Statistics of Scientific Procedures on Living Animal Great Britain 2011, shows that a peak in scientific procedures occurred in the early 1970s, when over 5.5 million procedures were carried out. After this time there was an overall decline until 2001, when figures dropped to around 2.6 million. Since 2001, however, there has been a gradual increase in the number of procedures performed and this trend has continued for 2011 during which 3.79 million scientific procedures were started, a 2% increase from 2010.

Scientific procedures are carried out on living animals for one of the following primary purposes: fundamental biological research; applied studies — human medicine or dentistry, and veterinary medicine; protection of man, animals or the environment; education and training; forensic enquiries; direct diagnosis; and breeding. In 2011, there was an increase in the number of procedures for: direct diagnosis (+1%), fundamental biological research (+3%), veterinary medicine (+17%) and protection of man, animals or environment (+54%). There was a decrease in the number of procedures carried out in the following categories: education (–31%) and human medicine/dentistry (–8%). The four most commonly used animal species in procedures were mice (71%), fish (15%), rats (7%) and birds (4%). Of the remaining 3%, reptiles and amphibians make up 0.5%, ‘other’ rodents 0.5%, and ‘other’ mammals 2%.

Statistics of Scientific Procedures on Living animals, Great Britain 2011 July 2012. A4 52 pages. The Stationary Office: London, UK. Any enquiries regarding this publication should be sent to: Home Office Statistics, 5th Floor, Peel Building, 2 Marsham Street, London SW1P 4DF, UK. ISBN: 978-0-1029-79503. Available online at: http://www.homeoffice.gov.uk/science-research/research-statistics/science/.

E Carter,

Educational website on humane endpoints for laboratory animals

In 2006, a CD-ROM on Humane Endpoints in Laboratory Animal Experimentation was released by the Netherlands Association for Laboratory Animal Science to raise awareness of this very important aspect of the use of animals in research. Since this time, a website, which incorporates and expands upon the information available on the CD-ROM, has been made available online through an initiative of the Netherlands Centre Alternative to animal use (NCA).

The website has an ‘open’ section, with unrestricted access for the general public, and a ‘closed’ section, which requires a username and password. Earlier this year it became possible for interested individuals to register online and request access to the secure area. Upon review, and acceptance, of an individual’s details, a username and password is then supplied. The ‘closed’ section is intended for the following people:

  • “Affiliated to an institute performing biomedical research and/or;
  • Involved in biomedical research, testing and education;
  • Trained as an investigator, animal technician or another position which is closed linked to animal research, testing and education;
  • Involved in relevant policy making activities, such as governmental organisations, regulatory bodies, etc; and
  • Or up to the decision of the project secretariat”.

The website defines a humane endpoint as: “the earliest indicator in an animal experiment of (potential) pain and/or distress that, within the context of moral justification and scientific endpoints to be met, can be used to avoid or limit pain and/or distress by taking actions such as humane killing or terminating or alleviating the pain and distress”.

An introductory section that is available to all web-users gives a general background on humane-endpoints and provides statistics on animal use in The Netherlands and other EU member states. The website then provides details of the normal physiology and behaviour of rats and mice (the species most commonly used in research) under the following headings: housing, activity, physical factors, social behaviour, senses and communication, nutrition, aberrant behaviour, pain-associated behaviour and physiological parameters. Humane endpoints are then described more fully, including: why humane endpoints should be used; types of humane endpoints; the implementation of humane endpoints in research; and the development and validation of humane endpoints. There are also interesting sections on relevant laws and regulations, links to documents that include material on humane endpoints and links to other, interesting organisations and information resources.

The secure part of the website, which requires a user to log-in, provides more detailed information on: animal behaviour; general and specific clinical signs; assessment of pain and distress; and pathology. More comprehensive information is also provided on the implementation of humane endpoints. Furthermore, logged-in users will have access to an interactive section which provides training and self-test material on various subjects, and allows users to contribute to a secure forum.

The website is available in English, French and Dutch and will be of use to all those interested in learning more about humane endpoints. Through making this information freely available it is hoped that the website will contribute to refining animal experiments by reducing the pain and distress experienced by rats and mice through the correct implementation of humane endpoints.

Humane Endpoints in Laboratory Animal Experimentation 2012 The website is an initiative of the Netherlands Centre Alternative to animal use (NCA) and is based on the CD-ROM ‘Humane Endpoints in Laboratory Animal Experimentation’ of the Netherlands Association for Laboratory Animal Science. Website available at: www.humane-endpoints.info.

E Carter,

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