Scientific & Technical Q&A

1. General

1.1. What is LAPS?

LAPS is a patented method to achieve an irreversible stun in poultry. Low atmospheric pressure is attained by using computer controlled slow decompression, which allows the body of the bird to adjust to changes in pressure and thus lose consciousness. LAPS sets a new paradigm for controlled atmospheric stunning without gaseous addition or electrical shock. The benefits of LAPS are not only humane, but also improve the economics of stunning and meat quality. LAPS has received a No-Objection letter from the USDA and CFIA and has the Seal of Approval for Humane Equipment by the American Humane Association.

1.2. How does LAPS work?

The exposure of conscious birds to slow, gradual decompression with a steady reduction in available oxygen leads to hypoxia. Hypoxia is the reduction in blood levels of oxygen, which reduces brain function and results in loss of consciousness. This coincides with loss of posture by the bird. The low blood oxygen levels also result in slowing of the heart rate and further reduction of brain functions to the extent that the bird is prevented from recovering consciousness. Holding the birds at a minimal pressure leads to an irreversible non-recovery state (death).

1.3. What happens to the birds during the LAPS cycle?

The exact timings vary a little between birds and also between temperature settings (a family of decompression curves that are applied automatically at different ambient temperatures due to changes in air density), so only averages and time ranges can be given. The LAPS cycle lasts 280 seconds for chickens. During the first 40 seconds, we see few behavioural responses (some birds show mandibulation), then they begin to become ataxic (beginning to lose balance and posture) and may show headshaking. Between 50-70 seconds the birds lose posture (this is a behavioural indictor of loss of consciousness and is corroborated with changes in brain state). A few seconds after loss of posture the birds begin to show convulsions (wing flapping - these are involuntary reflex responses and normal), and by around 140 seconds on average the birds are motionless (in a non-recovery state).

1.4. European Food Safety Authority

1.4.1. What is EFSA?

EFSA is a European agency funded by the European Union that operates independently of the European legislative and executive institutions (Commission, Council, Parliament) and EU Member States. It was set up in 2002 following a series of food crises in the late 1990s to be a source of scientific advice and communication on risks associated with the food chain. The agency was legally established by the EU under the General Food Law - Regulation 178/2002. The General Food Law created a European food safety system in which responsibility for risk assessment (science) and for risk management (policy) are kept separate. EFSA is responsible for the former area, and also has a duty to communicate its scientific findings to the public.

1.4.2. What does EFSA do?

As the risk assessor, EFSA produces scientific opinions and advice that form the basis for European policies and legislation. EFSA’s remit covers:

  • Food and feed safety
  • Nutrition
  • Animal health and welfare
  • Plant protection
  • Plant health

EFSA also consider, through environmental risk assessments, the possible impact of the food chain on the biodiversity of plant and animal habitats.

  • Since it was set up, EFSA has delivered scientific advice on a wide range of issues such as Bovine Spongiform Encephalopathy (BSE), Salmonella, food additives such as aspartame, allergenic food ingredients, genetically modified organisms, pesticides, and animal health issues such as avian influenza.
  • EFSA also play an important role in collecting and analyzing data to ensure that European risk assessment is supported by the most comprehensive scientific information available. It does this in cooperation with EU Member States.
  • Communicating on risks associated with the food chain is another key part of its mandate.
  • This means providing appropriate, accurate and timely information on food safety issues to raise awareness and explain the implications of our scientific work.
  • Scientific results cannot always be easily converted into simple guidelines and advice that non-scientists can understand. One of EFSA’s tasks, therefore, is to communicate clearly not only to its principal partners and stakeholders but also to the public at large, to help bridge the gap between science and the consumer.

2. Is LAPS Humane?

2.1. Is LAPS humane?

Most countries require that animals should be killed humanely. A humane kill is where the animal is spared any avoidable pain, distress, and suffering during their killing and related operations such as handling, restraint, stunning, and for bleeding. The LAPS scientific team, taking account of the results of behavioral, physiological, neurological studies and analgesic (pain killer) trials, have provided evidence that the LAPS process is humane (slaughter without avoidable fear, anxiety, pain, suffering, and distress).  In particular, the nature of the brain waves observed in birds in the early part of LAPS (slow waves) strongly suggest that LAPS is not aversive.

2.2. How do you know LAPS doesn't cause pain and suffering?

2.2.1. Summary

A randomized controlled trial was conducted which compared birds treated with an appropriate dose of analgesic (pain killer) and birds without the analgesic and there was no convincing evidence that the birds were experiencing pain during LAPS.

2.2.2. Detail

Pain can be detected in birds by changes in patterns of behaviour, demeanour, as well as specific pain behaviours e.g.; guarding behaviour of an injured limb; looking at or pecking a painful area; escape behaviours. Several studies on LAPS have included detailed second by second observation of birds in large groups, as well as in small groups to observe individual bird behaviour. A catalogue of defined behaviours (an ethogram) of poultry was prepared including their known response to a range of stunning methods. The behaviour of birds was recorded by an infrared video camera allowing for detailed analysis using specialist computer software. The time of onset and cessation and/or counts of each behaviour were recorded. Detailed statistical analysis examined the patterns of behavior of each bird in relation to the events of before, during, and after the LAPS cycle. It also allowed comparison of the behaviour of birds during LAPS in the light or the dark and a sham study to examine the effect of the chamber alone on bird behaviour. No birds were observed performing escape behaviour. The range and patterning of behaviour seen was consistent between trials and experiments and was strikingly similar to that seen with stunning with inert gases. A randomised controlled study was conducted to examine the behaviour of birds which had received a suitable dose of analgesic (pain killer). Very similar sequences of behavior were seen in treated and untreated birds and these relate primarily to hypoxia. There were some differences in latencies and counts of specific behaviours of the birds, possibly reflecting a smoother induction of unconscious in analgised birds. Collectively the results did not provide convincing evidence that birds undergoing LAPS are experiencing pain.

2.3. What approvals or no objections does LAPS have?

USDA and CFIA in Canada require that poultry stunning systems are humane, do not adversely affect product safety or inspection procedures. They approved LAPS (i.e. gave ‘No Objection’) in 2010 and 2013 respectively. The American Humane Association gave LAPS a Seal of Approval for Humane Equipment in 2011. The American Veterinary Medical Association noted that LAPS was humane in 2013 and produced detailed guidance for the use of LAPS for slaughter of all poultry in 2016. The European Food Safety Authority produced an opinion on LAPS in 2017 and concluded: “LAPS was found to provide a level of animal welfare at least equivalent to existing legally approved systems in the European Union.” The European Commission amended Annex I and Annex II of Council Regulation (EC) No. 1099/2009 on 16 May 2018 to include Low Atmospheric Pressure Stunning.

2.4. How did EFSA conduct its review on the humaneness of LAPS?

2.4.1. EFSA Guidance

In 2013 EFSA produced detailed guidance with the world’s highest standards for methodology and evidence which have to be met for the approval of any novel stunning systems in the EU. To meet the high standards introduced by EFSA, TechnoCatch commissioned an international program of scientific research to provide EFSA with comprehensive evidence on the welfare impact of LAPS including measures of behaviour, physiology, neuroscience, pain, pathology, environment, physics, and engineering, as well operational manuals and approvals.

2.4.2. EFSA Review

EFSA conducted a very detailed review of the evidence and sought additional data and studies which the scientists provided. EFSA found that the scientific data on LAPS exceeded that available for other stunning systems in poultry (e.g. electrical waterbath and controlled atmospheric (gas) stunning). Due to this lack of comparable data, EFSA could not make direct comparisons of LAPS to these systems.

2.4.3. EFSA Risk Based Approach for Welfare Hazards

EFSA use a risk based approach to their work rather than use the term “humane”. They rather try to assess the specific risks (in terms of impact, duration, and number of animals affected) to the welfare of animals of a stunning system. EFSA therefore used an expert panel methodology to rank and compare the welfare risks of the three systems.

2.5. How did EFSA score the welfare risks of LAPS compared with waterbath and gas?

The EFSA expert panel reported that the median welfare hazard score for LAPS was 3.5 whereas gas stunning (with carbon dioxide) scored 7 and electric waterbath stunning was most hazardous with a score of 10. Lower scores equal lower risk of welfare hazard and LAPS received the lowest score. This assessment shows that the LAPS method leads the field in humane slaughter and should be specified for high welfare poultry schemes above other stunning systems.

2.6. With regards to animal welfare, how does LAPS compare with a gas stunning system using CARBON DIOXIDE?

2.6.1. Avoids Handling

LAPS and gas stunning with carbon dioxide share the welfare benefits of avoiding the handling of conscious birds, which also provides a better working environment due to lower dust and fewer injuries for the birds and handlers.

2.6.2. Aversive

In gas systems using CARBON DIOXIDE, conscious birds may be exposed to levels of carbon dioxide gas that are aversive and cause respiratory effects. LAPS does not use any gases. Gasping and deep breathing of conscious birds are more commonly seen with carbon dioxide than with LAPS.

2.6.3. Carbon Dioxide System Design

Carbon dioxide systems vary in their design, some tip out birds onto conveyors and some keep the birds in drawers which go through tunnels of gas.  Some systems use deep pits and some use chambers.  Each system has advantages and disadvantages according to their design.

2.6.4. LAPS System Design

The LAPS process is computer controlled and has highly reproducible pressure curves tailored to the ambient conditions. LAPS consistently produces a humane stun and irretrievable loss of consciousness. The LAPS decompression rate cannot be altered by the operator and the system has full back up procedures in an emergency.

2.6.5. Operational Costs

Operational costs for gas stunning systems that use carbon dioxide are higher than LAPS because of the additional transport costs, storage costs, purchase costs, and supply risks of carbon dioxide.

2.6.6. Carbon Footprint

Because carbon dioxide is not used during LAPS, it has an additional benefit over carbon dioxide systems of having a lower carbon footprint as the energy involved in gas production and transport and storage are avoided.

2.7. Isn't killing poultry using inert gas the most humane method?

2.7.1. Avoids Handling

LAPS and gas stunning with inert gases such as Argon or Nitrogen share the benefits of avoiding the handling of conscious birds, thus providing a better working environment due to lower dust and fewer injuries for the birds and handlers.

2.7.2. Hypoxia

The behavioural and physiological responses of birds to inert gases and LAPS are similar as both produce loss of consciousness due to hypoxia. In 2004, EFSA stated that, “In this regard, the use of hypoxia (less than 2% by volume of oxygen) induced by argon, nitrogen, inert gases or mixtures of these may be the best option from an animal welfare point of view.

2.7.3. Inert Gas System Design

Few stunning systems for poultry using inert gases have been developed because nitrogen is particularly difficult to retain in gas stunning systems as it has similar density as air. Argon is slightly heavier than air, but it is expensive and the control of gas concentrations and homogeneity of the gas mixture remains challenging.

2.7.4. LAPS System Design

The LAPS process is by design a more reproducible and consistent way of achieving gradual hypoxia since decompression produces the same level of hypoxia throughout the chamber at a pre-defined rate.

2.7.5. Operational Costs

Operational costs for gas stunning systems that use inert gases are higher than LAPS because of the additional transport costs, storage costs, purchase costs of inert gases.

2.7.6. Carbon Footprint

Because no inert gases are used during LAPS, it has an additional benefit over argon systems of having a lower carbon footprint as the energy involved in gas production and transport and storage are avoided.

3. Is LAPS Cruel?

3.1. Isn't decompression dangerous?

In aviation and space medical science the effects of decompression are well understood. Explosive decompression occurs when pressure changes from ambient to near vacuum in less than 1 second. Rapid decompression is when it occurs in less than 10 seconds and slow decompression in more than 10 seconds. Smaller changes in barometric pressure can cause a variety of conditions in man and collectively are called dybarism. The LAPS process is not explosive or rapid decompression, and instead is somewhat equivalent to ascent in an unpressured aircraft. In man, during ascent, we observe loss of cognitive powers and motor skills, which precede an uneventful loss of consciousness. The stealth with which hypoxia can creep up on aircrew is the reason the aircrew have to be specially trained in stimulators to recognise the first signs of hypoxia. Such decompression may cause expansion of gases in closed cavities and this can cause pain in man including toothache, sinus and /or ear pain, and abdominal discomfort due to distension of air in the intestinal tract. Such signs are not seen for 15 minutes and whilst it is difficult to draw analogies between man and birds it appears unlikely they would be seen during the 50 to 80 second period in which birds are conscious in LAPS. There is a further range of conditions which occur with long term exposure to high altitudes such as decompression sickness and mountain sickness, but these require exposure of longer periods so are unlikely to be relevant to LAPS. Studies have been conducted to check if LAPS does cause such dysbaric effects on chickens. These have included pathological studies looking for damage (rupture of internal organs of the alimentary tract such as intestines colon, caecum, etc., as well as air sacs, lungs, joint cavities, and ruptured ear drums). No evidence has been found of ruptured internal organs or ear drums. An analgesic study was also conducted which may have revealed evidence of pain due to expansion of organs without rupture, but there was no convincing evidence that birds are experiencing pain.

3.2. Isn't it cruel to use a vacuum to kill animals as it can cause them to explode?

Historically, some vacuum methods that were used in some countries did not control the decompression rate and animals may have been rapidly exposed to near vacuum and suffered explosive or rapid decompression. This does not mean the animals exploded, but were subjected to explosive decompression. There is a misconception surrounding the word “explode”. These methods were correctly regarded as cruel and measures were taken to prevent their use. Low atmospheric pressure stunning has been carefully designed to ensure that the pressure curves used are gradual and do not cause explosive nor rapid decompression. A maximum rate of decompression is defined and the minimal holding pressure (which is approximately 20% of normal atmospheric pressure) has a wide safety margin to prevent such damage to birds. Clinical, pathological, and commercial studies do not provide any evidence that physical damage occurs to organs due to decompression in LAPS.

4. Is LAPS Legal For Use?

4.1. Is LAPS legal for use in the US?

Yes, it is legal to use LAPS for poultry in the US. The USDA gave LAPS “No Objection” in 2010.

4.2. Is LAPS legal for use in Canada?

Yes, it is legal to use LAPS for poultry in Canada. The CFIA gave LAPS “No Objection” in 2013.

4.3. Is LAPS legal for use in the EU?

Yes, it is legal to use LAPS in the EU. Council Regulation No 1099/2009 lays down measures to protect animal welfare during killing for commercial production and depopulation for disease control within the European Union. These measures also have to be met for any meat produced for export to the EU from third countries. This Regulation is widely regarded as having the highest welfare standards globally. Currently, the law allows the use of LAPS on broiler chickens weighing 4kgs or less and for the depopulation of chickens.  Further research is being conducted on broilers weighing more than 4kgs, layer chickens, and turkeys.  These limitations were put in place by EFSA due to the fact that all of the research was conducted on broiler chickens weighing less than 4kgs and not because of limitations of LAPS.  LAPS has successfully been used to irreversibly stun layer chickens, broiler breeder chickens, quail, and turkeys in the USA. Members States’ legislation and administrative practice may vary in the manner in which they allow new stunning systems to be trialed and used. Enquiries should be made of the relevant competent authority with regards to the use of LAPS in a particular country or region.

4.4. Is LAPS legal for use in the UK?

Yes, it is legal to use LAPS in the UK.  Currently, the law allows the use of LAPS on broiler chickens weighing 4kgs or less and for the depopulation of chickens.  Further research is being conducted on broilers weighing more than 4kgs, layer chickens, and turkeys.  These limitations were put in place by EFSA due to the fact that all of the research was conducted on broiler chickens weighing less than 4kgs and not because of limitations of LAPS.  LAPS has successfully been used to irreversibly stun layer chickens, broiler breeder chickens, quail, and turkeys in the USA.

4.5. Is LAPS legal for use in countries that export to the EU?

While the legality of using LAPS in each individual country is not known at this time, it is legal to export poultry stunned using a LAPS system to the EU as long as all the recommendations of Annex II of Council Regulation (EC) No. 1099/2009 are followed. The desire by a processor in a non-EU country to use LAPS will need to be discussed with the competent authorities in that country. It is assumed that with the approvals by the USDA, CFIA, and EFSA that getting LAPS approved in other countries shall be attainable.

4.6. What is the process for LAPS being included in Regulation (EC) No. 1099/2009?

EU Law allows for the Commission to introduce a novel or revised method to stun or kill animals, such as LAPS, providing that they have a positive opinion from EFSA as to whether the new method provides at least equivalent welfare to existing systems. When the EU Commission receives a positive opinion from EFSA on a novel stunning method, such as LAPS, they can then start a procedure to produce a proposal for a Commission Decision to change Regulation (EC) No. 1099/2009 to include LAPS. This then undergoes a legal process and approvals within the Commission. It is then passed to the Standing Committee on Plants, Animals, Food and Feed (PAFF Committee) for discussion and adoption. The Commission then arranges publication in the official journal and the Regulation is changed on the date of Publication or another date specified in the Decision. Then Member States can put in place procedures for the approval of the use of LAPS in poultry plants taking account of all the provisions of the Regulation and if necessary the advice of their national scientific support committee.

4.7. Has this amendment process been started?

Yes, this process has been started. It started the very same day that TechnoCatch, LLC received EFSA’s positive opinion on LAPS from the EC on 21 December 2017.

4.8. How long will the amendment process take?

The European Commission has advised TechnoCatch, LLC that this process should take between 3 months and 6 months.

4.9 When was the amendment officially approved by the European Commission?

5. What Species Can LAPS Be Used For?

5.1. Poultry?

Based on underlying physiology, there is no reason why LAPS should not work in the same way in all types of poultry. Research has only been published on LAPS use for broilers, but in the USA and Canada LAPS has also been used / is in use for quail, layers, broiler breeders, and large turkeys up to 23kgs. The results in broilers could be extrapolated to other species, such as domestic ducks perhaps, with slight modifications to the decompression curve.

5.2. Mammals?

The physiology of other farm animals such as pigs is different to birds and further research is required to determine if LAPS could be a humane approach. Mammals have a diaphragm and extendable lungs whereas birds have no diaphragm, but have large interconnecting air sacs and their lungs are not expandable. It has been speculated that the response of large mammals (such as farm livestock) may be similar to that of man exposed to ascent to altitude in an unpressurised airplane. This usually results in an uneventful loss of consciousness and death in man. A consortium project (University of Glasgow, University of Edinburgh, Scotland's Rural University College) is currently examining alternatives to CO2 stunning in pigs such as LAPS. This research project is co-funded by DEFRA and the Humane Slaughter Association with TechnoCatch, LLC providing equipment and technical support. LAPS has the potential to improve the welfare in pigs at the time of slaughter and following some proof of principle initial work, studies will examine in detail the behavioral and physiological response of pigs to LAPS.

6. Who Comprised The LAPS Scientific Team (SciLAPS)?

6.1 Who comprised the LAPS Scientific Team?

TechnoCatch, LLC examined the new EFSA Guidance (2013) and its team of advisers designed a multidisciplinary, international research program to fully meet the requirements of the EFSA Guidance. The team was coordinated by Dr David Pritchard, MRCVS, and independent consultant, London, UK; and included Dr Dorothy McKeegan (Scientific Lead), University of Glasgow, UK; Dr Jessica Martin, University of Edinburgh, UK; Professor Malcom Mitchell, Scotland’s Rural University College, UK; Professor Emeritus Yvonne Vizzier Thaxton, Mississippi State University & University of Arkansas, USA, Dr Karen Christensen, Tyson Foods, formerly University of Arkansas, USA; Dr Marien Gerritzen, Wageningen University and Research, NL; Professor Paul Holloway, University of Florida, USA.

7. What Scientific Papers Have Been Published On LAPS?

7.1. LAPS first submission 2013:

7.1.1. McKeegan, D.E.F., Sandercock, D.A., Gerritzen, M.A. 2013. Physiological Responses to Low Atmospheric Pressure Stunning and the Implications for Welfare. Poultry Science, Vol. 92, 858-868.

7.1.2. Vizzier-Thaxton, Y., Christensen, K.D., Schilling, M.W., Buhr, R.J., and Thaxton, J.P. 2010. A new humane method of stunning broilers using low atmospheric pressure. Journal of Applied Poultry Research, Vol. 19, 341 – 348

7.1.3. M. W. Schilling, V. Radhakrishnan, Y. Vizzier-Thaxton, K. Christensen, P. Joseph, J. B. Williams, and T. B. Schmidt (2012)The effects of low atmosphere stunning and deboning time on broiler breast meat quality 2012 Poultry Science 91 :3214–3222

7.1.4. V. Battula, M. W. Schilling, Y. Vizzier-Thaxton, J. M. Behrends, J. B. Williams, and T. B. Schmidt (2008) The Effects of Low-Atmosphere Stunning and Deboning Time on Broiler Breast Meat Quality 2008 Poultry Science 87:1202–1210 doi:10.3382/ps.2007-00454

7.2. LAPS Second submission 2016

7.2.1. Nikki Mackie, Dorothy E. F. McKeegan 2016 Behavioural responses of broiler chickens during Low Atmospheric Pressure Stunning Applied Animal Behaviour Science 174 (2016) 90–986.

7.2.2. Jessica E. Martin, Karen Christensen, Yvonne Vizzier-Thaxton, Dorothy E. F. McKeegan (2016) Effects of analgesic intervention on behavioural responses to Low Atmospheric Pressure Stunning Applied Animal Behaviour Science 180 (2016) 157–165

7.2.3. Jessica E. Martin, Karen Christensen, Yvonne Vizzier-Thaxton, Malcolm Mitchell, Dorothy E. F. McKeegan (2016) Behavioural, brain and cardiac responses to hypobaric hypoxia in chickens Physiology and Behavior 163 (2016) 25–36.

7.2.4. Jessica E Martin, Karen Christensen, Yvonne Vizzier-Thaxton, Dorothy E. F. McKeegan (2016) Effects of light on responses to Low Atmospheric Pressure Stunning in broilers. British Poultry Science 57 (2016) 585–600

7.2.5. Paul H. Holloway, David G. Pritchard (2017) Effects of ambient temperature and water vapor on chamber pressure and oxygen level during Low Atmospheric Pressure Stunning of poultry. Poultry Science (2017) 0 1–12.

7.3. Other reviews on LAPS

7.3.1. AVMA Guidelines for the Humane Slaughter of Animals: 2016 Edition

7.3.2. Meyer R 2015 in Veterinary anesthesia and Analgesia Fifth Edition edited by Lumb and Jones edited by Kurt A. Grimm, Leigh A. Lamont, William J. Tranquilli, Stephen A. Greene, Sheilah A. Robertson, Wiley Pub Ames Iowa Chichester UK

7.3.3  Johnson C L 2014A review of bird welfare during controlled atmosphere and electrical water JAVMA, Vol 245, No. 1, July 1, 2014

8. What did the most recent research chicken behaviors during LAPS show?

In the more recent work on LAPS, the SciLAPS team conducted detailed behavioral observations which provide indicators of welfare and allow direct comparisons to other types of stunning (gas). This work showed that the range and patterning of behavior seen during LAPS is very similar to that seen with gas stunning with inert gases. The SciLAPS team also measured behavior, ECG (heart rate) and EEG (brain waves) in the same individual birds, which allowed the SciLAPS team to accurately determine the time of loss of consciousness by corroborating behavioral and brain responses. In another research trial birds were subjected to LAPS with and without a dose of a pain relieving drug, to determine if any of the behavioral responses that are seen might change, which would suggest the behaviours are pain related (there was no convincing evidence for pain). Another research trial focused on conducting LAPS in the light and in the dark, and the results indicated that birds became unconscious slightly more quickly in the dark (LAPS is normally conducted in the dark). These results also showed that being in the dark induces a drowsy state in the birds from the start of the LAPS process. It is known from other peer reviewed scientific work that if the birds were in pain or in a state of fear in this phase, that they would 'wake up' and the EEG does not show this – thus providing more evidence that birds are not suffering during the LAPS induction to unconsciousness. Finally, birds were placed in the LAPS chamber without turning it on, to distinguish between behaviors caused by placement in a novel environment versus undergoing LAPS. The research showed that almost all the behaviors recorded are due to LAPS and not placement in the chamber. Collectively, this work provides a very comprehensive welfare assessment of the LAPS system that proves that LAPS does not cause anxiety, pain, distress, or suffering.