Frequently Asked Questions - Slaughter

Every year millions of animals are slaughtered for human consumption.  Below is a Table providing the estimated number of cattle, pigs, sheep, and chickens slaughtered in 2020 in the UK, Europe, and the World (Source: FAOStat).

Data on fish are only available in terms of weight, so the number of individual fish slaughtered is difficult to estimate. Mood et al. (2023) used estimated mean weights for farmed fish species at slaughter to estimate numbers killed for food globally from FAO data. They arrived at 120 billion farmed fishes killed in 2019 worldwide, of which 810 million were slaughtered in the EU, and 51 million in the UK.

EU Council Regulation (EC) No. 1099/2009 protects animals at the time of slaughter or killing. The Regulation is directly applicable in all EU Member States but does not prevent Member States from maintaining any national rules aimed at ensuring more extensive protection of animals. The same regulation is applicable in the United Kingdom as Retained EU law and is implemented by the Welfare of Animals at the Time of Killing (WATOK) Regulations for England (2015), Wales (2014), Scotland (2012) and Northern Ireland (2014),. They stipulate that animals bred or kept for the production of meat, skin, fur or other products must be spared any avoidable pain, distress or suffering during movement, whilst in lairage (keeping animals in stalls, pens, covered areas or fields at a slaughterhouse before they are slaughtered), and during restraint, stunning, and slaughter or killing.

Slaughter can be humane if an animal is protected from avoidable pain, distress or suffering. To achieve this, the animal must be gently but effectively restrained and then stunned, rendering it instantaneously insensible to pain, and then bled rapidly and effectively to ensure death before recovery can occur. If a stunning method does not cause instantaneous unconsciousness, the method must be non-aversive (i.e. must not cause fear, pain, or other unpleasant feelings) to the animal before it becomes unconscious.

Humane slaughter relies on multiple processes; hauliers, operators, stockpersons, slaughter personnel and equipment must all work to their optimum, and in accordance with legislation, in order to ensure high welfare throughout the slaughter chain.

In England and Wales, the Food Standards Agency (FSA) is responsible for ensuring legislative compliance with animal health and welfare controls in licensed fresh meat premises; in Scotland it is Food Standards Scotland (FSS) and in Northern Ireland it is the responsibility of the Department of Agriculture, Environment and Rural Affairs (DAERA). These organizations employ Official Veterinarians (OVs) and Authorized Meat Inspectors (AMIs) to ensure slaughterhouse compliance with animal welfare, meat hygiene and other statutory requirements.

Official Veterinarians (OVs) enforce animal welfare and meat hygiene legislation in the UK and the EU. They may take preventative and corrective actions to ensure compliance with regulations: these may include verbal or written non-compliance notices and warnings and, when necessary, recommendations for prosecution. If OVs witness animals arriving at a slaughterhouse showing evidence of poor welfare arising on farm or during transport, they will report the incident to the appropriate enforcement body which will take the necessary investigative action. 

Monitoring of animal welfare at slaughter is a multi-disciplinary procedure, involving CCTV (closed-circuit television), manual checks and paper exercises to ensure compliance with standard operating procedures (SOPs).  The use of CCTV to cover all live-animal operations has been statutory in England since November 2018; in Scotland since July 2021; and it will become law in Wales in late Spring or Summer 2024.  In Northern Ireland, all licensed abattoirs have CCTV, so it has been deemed not necessary to introduce targeted legislation. 

Major retailers require their suppliers to comply with detailed welfare standards specified by the retailers themselves, and these retailers may employ independent auditors to ensure that their suppliers adhere to these specific welfare standards.

All animals slaughtered in licensed slaughterhouses in the UK and the EU should be treated humanely, in accordance with legislation. Retailer standards, and welfare requirements of individual suppliers may exceed statutory requirements, and there are many farm assurance schemes operating in the UK, the EU, and the US, that lay down minimum animal welfare standards. Producers, hauliers, and abattoirs which seek accreditation to a given scheme must comply with these standards. Retailers frequently specify their own welfare standards to which all their suppliers must adhere. Increasing numbers of consumers are concerned about the welfare of farmed livestock. If you are specifically concerned with the welfare of animals at slaughter and killing, it is worth researching retailers' welfare policies and assurance schemes, particularly those geared towards welfare beyond the farm gate.

Details of the majority of farm assurance schemes in the UK, the EU, and the US can be found online. If a meat product is accredited to a scheme, it should be clearly displayed on the product's label. Ask your butcher or food retailer about the accreditation of their suppliers.

Adult cattle may be restrained in a stunning pen, usually a solid-sided metal box with a vertical sliding door at one end to allow the animal to enter. Such a pen often has a device that restricts the movement of the animal's head to permit accurate stunning. This is a requirement in the UK and EU but not in all parts of the world. Some may use a halter to keep the head still. In the UK, the majority of cattle are stunned with a captive-bolt device. Alternatively, cattle can be stunned using electricity (head-only), or stunned and killed using electricity (by applying an electric current to the head and heart simultaneously).

If using a captive-bolt, the slaughterperson stands on a platform, in front or to one side of the pen and shoots the animal in the centre front of the head, aligned between the eyes and the ears in order to accurately target the brain. This renders the animal unconscious. The pen side then opens, and the unconscious animal rolls out of the pen, is shackled by one hind leg, hoisted on to an overhead conveyor and moved to the bleed area. Here, the animal is bled by the severance of all major blood vessels supplying the brain with oxygenated blood. This causes profusive bleeding that leads to rapid death, i.e. the animal dies from loss of blood before it makes any recovery from the percussive stun.

For more details, see the HSA online guide for captive-bolt stunning of livestock and Captive-bolt Stunning and Signs of Unconsciousness in Adult Bovines.

In large abattoirs, sheep are often mechanically carried the short distance from the lairage to the stunning area in single file in an inverted V-shaped restrainer conveyor, which gradually lifts the animal from the floor. In small slaughter plants, sheep are moved in groups to a pen where they are individually stunned.

Sheep may be stunned using either electricity or a captive-bolt device. This renders the animal unconscious. Sheep may also be stunned and killed using electricity; this is usually referred to as a head-to-back stun-kill. They are then shackled by one hind leg, hoisted on to an overhead conveyor and moved to the bleed area. Here, the animal is bled by the severance of all major blood vessels that supply the brain with oxygenated blood. This causes profusive bleeding that leads to rapid death, i.e. the animal dies from loss of blood before recovering from the stun.

For more details, see the HSA online guides for captive-bolt stunning of livestock and electrical stunning of red meat animals.

There are two types of stunning method for pigs, electrical or carbon dioxide (CO₂ ). When electrical stunning is used, pigs may be brought to the stunning point in an inverted V-shaped restrainer-conveyor a monorail conveyor or be penned in groups and stunned individually using electricity.

CO₂ anaesthesia is also used in a number of large abattoirs. Pigs are lowered, preferably in groups, into a chamber containing a minimum concentration of 80% CO₂ mixed in the air. The pigs lose consciousness and, in the UK, must remain in the gas mixture until dead. For adult pigs, a minimum dwell time of 2.5 minutes is required to ensure the animals are killed by the gas. Signs of an effective stun and kill include loss of posture, no rhythmic breathing, failure to respond to external stimuli (e.g. pricking their nose) and lack of corneal reflex.

Following electrical stunning, there may be some random muscle movement, but on its own, this is not a sign that the animal is still conscious (see FAQ on movement after stunning for further info).

Whether pigs have been stunned and killed using CO₂, or just stunned by electricity, they should be bled without delay, preferably within 15 seconds. For this, the animals are shackled by one hind leg, hoisted on to an overhead conveyor and moved to the bleed area. Here, the animal is bled by the severance of all major blood vessels which supply the brain with oxygenated blood. This causes profusive bleeding that leads to rapid death, i.e. the animal dies from loss of blood before it makes any recovery from the stun.

Large-scale poultry processing plants use electrical water baths or gas (controlled atmosphere stunning; CAS) to stun the birds. Some abattoirs in the US are using low atmosphere stunning (LAPS).

For electrical waterbath stunning, poultry are unloaded from their transport containers and suspended by both legs onto a moving shackle line, which moves them to the waterbath. The birds' heads swing into the electrified water in the bath and a stunning current passes from their heads, through their bodies, to their feet in the shackles; this causes them to become unconscious. The electrical parameters of the waterbath can be set to either stun the birds or stun and kill them. To ensure all birds die, they are then cut at the neck as soon as possible after they exit the waterbath, leading to rapid blood loss and death.

Controlled Atmosphere Stunning (CAS) systems kill birds by exposure to CO₂ or an anoxic gas mixture (a gas mixture that does not contain oxygen), which rapidly renders them insensible to pain or distress. Although the name suggests that birds are only stunned, UK legislation demands that birds must be killed whilst they are still in the gas mixture and before they are shackled. The birds are moved through a chamber containing the gas mixture that causes them to become unconscious and then die. In some systems birds remain in their transport containers so there is minimal handling; others unload the birds prior to entry to the controlled atmosphere machine.

Low atmosphere stunning (LAPS) is used in some poultry processing plants in the US. The birds are placed in a chamber where controlled reduction in air pressure causes oxygen depletion, leading to unconsciousness and death.

Every year, around the world, millions of farmed fish are slaughtered for human consumption. Fish react to painful stimuli in a similar way as do terrestrial livestock, and the welfare of farmed fish should be protected throughout the pre-slaughter handling. All farmed fish should be stunned effectively, causing instantaneous insensibility, before being bled.

Traditional methods of killing fish include asphyxiation out of water, exposure to carbon dioxide, exposure to very low temperatures on an ice bed, and bleeding without stunning. These procedures take several minutes to induce insensibility, are not humane and should not be used.

Electrical and percussive stunning methods for fish are now becoming more common. Current electrical systems include waterbath stunning systems, using either an enclosed pipe system, or a metal de-watering grid followed by a conveyor belt system which passes fish through electrified water to stun them. Research has been directed at determining optimum electrical parameters for stunning different species, as tolerances vary widely. Percussive stunning of fish has been modernised with the development of automated percussive flow-through systems, which remove the need for human intervention and retain the fish in water until the point of stunning.

Aquaculture is an expanding industry and there has been considerable research recently to improve welfare at stunning and slaughter. The HSA plays a role in helping industry to apply this research to commercial practice.

The HSA has produced Guidance Notes on Humane Harvesting of Salmon and Trout which provide guidance on the humane handling and killing of salmon and trout. The publication describes the different slaughter methods used, how higher welfare practices can be implemented, and the meat quality implications of using these methods.

For more information about the welfare of farmed fish at slaughter, please view the HSA finfish consumer video, also available on the HSA homepage.

Post-stun movement is – perhaps surprisingly – an expected result and a sign of an effective stun or stun-kill. The important organ in the context of stunning is the brain.  Following an effective percussive blow (eg by captive bolt device), or electrical insult, the brain is no longer functioning.  Once the brain is not functioning, spinal reflexes are released from the control otherwise exerted by the functioning upper-brain, leading to post-stun movements.  These will gradually subside.

From birth, the brains of fully conscious animals, and humans, are constantly suppressing brain-stem reflexes.  When a healthy animal is stunned prior to slaughter, this control by the upper brain (cerebral cortex), the part which is responsible for consciousness and cognition, ceases to function and loses control of the brain stem (medulla oblongata); the normally suppressed brain-stem reflexes are then manifested in convulsions.  These convulsions vary in intensity and duration according to the species, age, and health status of the animals, as well as the depth of concussion incurred and the method of stunning.  Post-stun movement is not a sign of consciousness; indeed, with electrical stunning, an exaggerated kicking phase, following the initial period of rigidity, is indicative of an effective stun. 

Yes, electrical stunning is humane when performed correctly.

Electrical stunning of livestock (also known as electronarcosis) causes immediate insensibility to pain. This is because the electrical current renders the animal unconscious before the nerve supply can transmit the signal of pain from the stunning. Sufficient current should be passed through the brain for a sufficient period of time at the optimum voltage, frequency, and waveform to ensure insensibility. These requirements are laid out in legislation (EC 1099/2009) and the HSA’s recommendations can be found in our publications on mammals and birds.

A captive-bolt device induces instantaneous insensibility by administering a severe blow to the skull of an animal. There are two broad categories of device, penetrative and non-penetrative. Penetration of the skull is not required to induce insensibility; concussion can be caused by massive shearing forces which accelerate the brain within the skull in the absence of actual penetration of the skull or brain tissue. An effective percussive stun is characterised by immediate collapse of the animal, with exaggerated tonic activity (rigid muscle tension), no rhythmic breathing, no corneal reflex and a relaxed jaw.

Captive-bolt stunners may be trigger-fired or fired on contact with the animal’s head.  Captive-bolt devices are used mainly for stunning cattle, sheep, goats and some farmed deer. Pigs are usually electrically stunned as they show exaggerated clonic activity (convulsive spasms and paddling of the legs) when percussively stunned, resulting in a risk to operator’s safety when hoisting, bleeding or further processing the animal. For adult pigs, it is therefore recommended that they are stunned electrically or killed using a free-bullet humane killer or shotgun. 

Captive-bolt devices may be powered by cartridges or compressed air. Cartridges vary in strength and different strengths will be required depending on the type of stunner, and the size, age, and species of animal.

The HSA Guidance Notes on Captive-Bolt Stunning of Livestock provide further details on choosing the correct ammunition and device for the animal you wish to stun, on the use of captive-bolt equipment including how it works, effective stunning, bleeding, restraint and safety. See also this UK Government link on captive bolt stunning for further information.

 Further information can be obtained from this UK Government link on captive-bolt stunning and this FSA link .

In some countries, such as New Zealand, all animals are required to be stunned prior to slaughter, even if they are killed according to religious requirements. However, in the UK, there are specific provisions within the legislation allowing sheep, goats, cattle, and poultry to be slaughtered without prior stunning providing various criteria are met.

The UK legislation [WATOK Regulations for England (2015), Wales (2014), Scotland (2012) and Northern Ireland (2014)], allows slaughter without prior stunning and this can only be performed in a licenced slaughterhouse, for the consumption of people practising the Muslim and Jewish faiths. As well as holding Certificates of Competence, slaughter personnel must have additional specific (religious) qualifications in place in order to perform this. The legislation stipulates that the animals must be spared any avoidable suffering, pain, or distress. 

Other aspects of UK legislation laid out in WATOK to protect animal welfare remain in force, along with the CCTV legislative requirements.

Results from the 2022 survey on stun and non-stun slaughter in England and Wales, conducted by the Food Safety Standards (FSA), are published by DEFRA and the Welsh Government.

In the UK, the website of The Food Standards Agency (FSA) provides a comprehensive list of all EU approved animal slaughterhouses and processing plants in the UK, detailing the species they are legally allowed to slaughter and their geographical location within the UK. In the EU, information about similar establishments can be found on this webpage.

Please note that, in the UK, there are restrictions on the slaughter of cattle over 30 months due to TSE (transmissible spongiform encephalopathies), so check that your abattoir is appropriately licensed.  

The HSA is happy to undertake visits to provide independent and confidential advice to slaughterhouses on animal welfare aspects and can also undertake animal welfare assessments on request.  For more information, see the Advice page on the HSA website.

In the UK, slaughter of animals by their owners for their own consumption, and that of their immediate families living in the same household, does not require the owners to have a WATOK Licence (slaughter licence).  They must, however, slaughter the animals without causing “avoidable pain, distress or suffering during their killing and related operations” which is also a requirement in the EU (EC 1099/2009, Article 3.1).  Compliance with animal by-products legislation is also statutory.  Where animals are being slaughtered for home consumption in the UK by a person for the owner, a CoC or WATOK Licence is required, along with compliance with meat hygiene and animal by-products disposal legislation.

The Food Standards Agency (FSA) in England and Wales has produced a document on the law surrounding home slaughter, and the HSA Technical Note number 8 also covers this topic

A firearm certificate is no longer required for purchase, possession, carriage or use of captive-bolt stunners in the UK. However, a valid WATOK slaughter licence or Certificate of Competence (CoC) is required to use any captive-bolt device for the purpose of stunning livestock, except in emergency or casualty situations. Operators should be fully trained and knowledgeable regarding the positioning, firing, maintenance, ammunition, and effectiveness of captive-bolt stunners. It should always be remembered that captive-bolt devices are percussion stunners, not humane killers. Therefore,  stunning should always be followed by immediate bleeding or pithing (destruction of the brain via the hole left by the bolt using a metal rod, or similar) to ensure death.  Cattle, sheep, and goats intended for consumption must not be pithed; they must be bled. 

Yes, some firearms are suitable for killing farmed animals humanely and safely, provided they are used correctly.  The operator should be aware that these weapons discharge free projectiles, which may exit the carcase and endanger other animals and humans in close proximity, if used incorrectly.  The operator must also have a Firearm Certificate which authorizes the use of the firearm for this purpose. 

The types of weapons and ammunition suitable for this purpose are detailed in the HSA publication Humane Killing of Livestock Using Firearms, which provides guidance on the use of shotguns or free bullet weapons including correct gun operation, ballistics, how animals should be shot, types of equipment available, using the right ammunition, safety, and maintenance. 

See also the Opinion on the welfare of animals killed on-farm (2017) by the Farm Animal Welfare Council (UK).

Legal methods of killing poultry currently include neck dislocation. However, the HSA has reservations about this method. In neck dislocation, it is difficult to consistently achieve an immediate loss of consciousness. As such, there is potential for distress, pain, and suffering. The HSA recommends that neck dislocation should only be used in emergencies or for very small numbers of birds where no better method is available. The legislation only permits the use of manual neck dislocation in poultry up to 3 kg bodyweight, and up to 5 kg bodyweight if a mechanical method is used, such as the NEX.

You do not require a slaughter licence to carry out neck dislocation on the premises on which the birds were reared. Where possible, the HSA advises the use of other methods such as electrical or mechanical concussion stunning. Hand-held electrical stunners and mechanical percussive devices are available (see the HSA publication Practical Slaughter of Poultry – A Guide for the Small Producer online guide or booklet for details). When used as per the manufacturer’s instructions, these methods should cause instantaneous insensibility. They must be immediately followed up by bleeding to kill the bird whilst the bird is unconscious.

On-farm slaughter of poultry requires the correct training and equipment.  It is advisable to familiarise yourself with local legislation and obtain training before using this type of equipment for any purpose, whether commercial or private. The HSA has documents covering various aspects of these procedures; from catching and handling the birds, practical guidance on the humane slaughter of poultry using captive-bolt devices, and effective neck cutting.  The HSA’s Technical Note for small scale and seasonal producers may also be useful.

The HSA provides one-day training courses for those who wish to learn how to use electrical stunners and percussive devices. At some courses, participants can also be assessed for a WATOK poultry slaughter licence. See the Training & Education page for more information.

On-farm slaughter of cattle, sheep, pigs, and goats is extremely difficult to carry out legally in terms of food hygiene, disease controls, and in terms of application of humane methods of restraint, stunning and slaughter. When slaughtering on-farm, there are several regulations of which you need to be aware. These are in place to safeguard animal welfare and food safety. There are also environmental regulations (e.g. controlling the disposal of by-products), aspects of which may vary both within and between countries. It is therefore important that you check with your Local Authority before carrying out any of the tasks related to home slaughter.

Welfare at slaughter must be upheld in accordance with Council Regulation EC 1099/2009 on the Protection of Animals at the Time of Killing and The Welfare of Animals at the Time of Killing Regulations  (WATOK) for England (2015), Wales (2014), Scotland (2012) and Northern Ireland (2014). It is an offence to cause any avoidable pain, distress or suffering to an animal during its killing and related operations. It is also an offence to sell or to supply to another person (other than immediate family), meat that has not been slaughtered and health marked in a licensed abattoir.

The HSA has produced a technical note, On-Farm Slaughter of Livestock for Consumption, which provides in depth information to help make an informed and welfare-friendly decision regarding on-farm slaughter. Guidance on home slaughter in the UK is available online from Gov.uk. Further information regarding home kills and associated legislation is available from the Food Standards Agency website.

Yes, this is lawful in the UK. If you are not prepared to carry out the slaughter process yourself, then you can employ a licensed slaughterer to kill and dress the animal/s on farm under your responsibility and supervision. The slaughterer must hold a Certificate of Competence (CoC) or a WATOK Licence for the relevant activities which indicates they have the knowledge and skill necessary to perform the tasks humanely and efficiently. Any licensed slaughterer should be able to produce evidence of their licence.

Carcases or parts of carcases from home slaughter livestock, other than those being disposed of as animal by-products, cannot be removed to another premises for processing. The meat from a home slaughtered animal can only be consumed by the owner and/or that of their immediate family living in the same household. The sale or gifting of meat from a home slaughtered animal is not permitted.

For further information, see the FSA guidance on the HSA webpage.

In the UK, monitoring slaughter, and enforcing legislation, outside the curtilage of licensed abattoirs, e.g. on-farm seasonal slaughter of poultry, is the domain of the Animal and Plant Health Agency (APHA) and the Trading Standards and Environmental Health Departments of the local authority in which the premises are located. 

In the UK, the welfare at the time of killing (WATOK) regulations states that if you intend to engage in any one or more of the following operations, you must possess a valid Certificate of Competence (CoC) or WATOK Licence:

• handling of animals prior to slaughter
• restraint of an animal for the purposes of stunning, slaughtering or killing
• stunning, slaughter or killing of animals
• pithing and assessment of effective pithing of stunned animals
• assessment of effective stunning or killing
• shackling or hoisting of stunned animals
• bleeding of animals which are not dead

The requirement for a licence does not apply to any person who:

• holds a certificate registered with the competent authority, provided that the scope of the certificate extends to the operation being undertaken;
• works in the presence, and under the direct supervision, of a person who holds a certificate or licence registered with the competent authority, provided that the scope of the certificate or licence extends to the operation being undertaken;
• works in the presence, and under the direct supervision, of a veterinary surgeon;
• carries out the emergency killing of an animal;
• kills an animal other than for a commercial purpose;
• for purposes other than human consumption, kills an animal in the field by means of a free bullet;
• for purposes other than human consumption, kills poultry by means of cervical dislocation (where there are no other methods available for stunning) on premises forming part of an agricultural holding on which the poultry were reared;
• kills an animal for the purpose of depopulation;
• kills surplus chicks or embryos in hatchery waste;
• is a veterinary surgeon acting in the exercise of the veterinary surgeon’s profession;
• is an owner of an animal killing it for private domestic consumption (when slaughter takes place elsewhere than in a slaughterhouse or knacker's yard). See answer to question 14 above for further details.
• kills an animal in circumstances which are out of scope of the EU Regulation, i.e.:
  • during scientific experiments carried out under the supervision of a competent authority;
  • during hunting or recreational fishing activities;
  • during cultural or sporting events;
  • poultry, rabbits and hares slaughtered outside of a slaughterhouse by their owner for private domestic consumption

A Certificate of Competence (CoC) is normally issued to slaughter personnel working in a licensed abattoir.  In the UK, it involves both a paper and practical assessment by assessors registered with an approved centre and accredited by Food and Drink Qualifications (FDQ).  In order to obtain a CoC, one would normally be assessed in a licensed abattoir.  If the person being assessed is not an employee of the abattoir, then this has to be arranged with agreement from the OV and the Food Business Operator (FBO).

In England and Wales, but not in Scotland or Northern Ireland, there is an alternative to the CoC for those slaughtering outside the curtilage of a licensed abattoir, such as seasonal poultry processors and knacker personnel.  This document is known as a WATOK Licence and the procedure for its acquisition is a little different to that of the CoC. 

For further information go to:

https://www.gov.uk/guidance/get-a-certificate-of-competence-or-licence-to-slaughter-or-kill-animals

https://www.gov.uk/government/publications/welfare-of-animals-at-the-time-of-killing-licence-application