Red meat slaughterhouses: restraining, stunning, killing animals

Stunning pens, restraining boxes, captive bolt, gas and electrical stunning equipment, bleeding animals and restraining methods.

If you operate a red meat slaughterhouse (abattoir) you must ensure that anyone working in it has a certificate of competence (CoC) if they do any of the following:

  • handle animals
  • stun animals
  • pith animals
  • restrain animals
  • shackle animals
  • hoist animals
  • bleed live animals
  • check stunning has worked
  • check pithing has worked

You risk being prosecuted and losing your CoC if you do not follow these and other Welfare of Animals at the Time of Killing (WATOK) requirements.

If you’re responsible for stunning, hoisting and bleeding animals, you must carry out all operations on one animal before moving to the next.

You must install and operate a CCTV system that can covers the areas where live animals are present. These include unloading, lairage (holding areas), handling, restraint, stunning and killing areas. The CCTV system must keep recorded images and information for 90 days. Youmust give inspectors access to the CCTV system and recordings.

Find more information in CCTV in slaughterhouses: rules for operators.

Restraining animals

You must restrain an animal before you stun or kill it. Your equipment for restraining animals must:

  • be in good working order
  • allow you to stun or kill an animal effectively
  • prevent injury or cuts to animals
  • minimise struggling and vocalisation
  • minimise the time an animal’s restrained

You must only put animals into restraining equipment, including head restraints, when you’re ready to stun or kill the animal.

Stunning pens for cattle

You must use a stunning pen or restraining pen for adult cattle, including bovine animals such as buffalo and bison.

You must only use restraining equipment in the way described in the manufacturer’s instructions.

Stunning pens and restraining boxes must:

  • be in good working order
  • only accommodate one animal at a time
  • prevent any large movements forwards, backwards or sideways
  • allow complete access to an animal’s forehead

Stunning cattle with a pneumatic captive bolt

If you use pneumatic captive bolts you must have a restraining device in any new stunning pens and restraining boxes you’ve bough since 1 January 2013. Your restraining device must:

  • restrict an animal’s head from moving both up and down, and side to side
  • allow the release of an animal’s head immediately after stunning

All stunning pens and restraining boxes used with a pneumatic captive bolt must have this device by 8 December 2019.

Religious slaughter

If you carry out religious slaughter on cattle, sheep or goats, you must use restraining equipment and follow the additional rules regarding restraining an animal.

The Food Standards Agency (FSA) must approve cattle restraining pens before they’re used for religious slaughter.

Killing horses

You must kill a horse in a separate room or a bay from other animals. The room must only be used for this purpose.

You cannot kill a horse:

  • in sight of another horse
  • in a room where there are remains of another horse or other animal

Restraining methods you must not use

You must not use the following methods as a way of restraining animals:

  • suspending or hoisting conscious animals
  • clamping or tying an animal’s legs or feet
  • severing an animal’s spinal cord
  • immobilising an animal with electrical stunning equipment or electric shock devices

Animal stunning and killing

You must stun all animals before you kill them, unless you’re carrying out religious slaughter.

When you stun an animal, it must remain unconscious and unable to feel pain until death. Once you stun it, you must kill it immediately. You can use stunning methods that instantly kill an animal, for example using a gun or rifle.

Simple stunning

Simple stunning is where you stun an animal unconscious but do not instantly kill it. You must immediately use a follow-up procedure to kill the animal before it recovers consciousness, such as bleeding (cutting both neck arteries, the carotid arteries).

Monitoring animals for consciousness

Between stunning and killing, you must check animals for signs of consciousness and unconsciousness.

You must have a CoC on checking the effectiveness of stunning. Your slaughterhouse’s standard operating procedure should also list what monitoring procedures will be used for each type of animal.

Someone, usually an animal welfare officer (AWO), should monitor each slaughter line to check animals are being stunned effectively.

Review your sampling rate

You must check that stunning is effective. How often you do this depends on risk factors such as:

  • how often you change the species or size and weight of animals on a slaughter line
  • the length of each slaughterman shift
  • the results of previous sampling - you’ll need to increase the sampling rate if a previous check found a percentage of animals were not effectively stunned

If you find an animal that has not been properly stunned, you must take immediate action in line with your slaughterhouse’s standard operating procedure.

If you fail to stun an animal properly, you must first re-stun the animal and then find out what’s wrong and correct your operation immediately.

What to record

You must check a representative sample of the animals you’re stunning. For each sample, you must record:

  • the number of animals checked
  • the name of the person monitoring
  • the time and circumstances, such as immediately after stunning an animal
  • any factors affecting the efficiency of the stunning process
  • whether your findings are consistent with previous monitoring
  • tests of unconsciousness and how to interpret the results
  • religious slaughter - tests for signs of life and how to interpret the results

Stunning or killing: equipment and methods

Any equipment you use for stunning or killing must:

  • stun or kill rapidly and effectively
  • be in good working order
  • have the manufacturer’s instructions on how to operate it

You must have back-up stunning equipment available immediately on the spot, in case your main equipment fails.

Maintain your equipment

You must maintain equipment following the manufacturer’s instructions.

You must keep maintenance records for at least a year. The FSA can ask to see them.

Electrical stunning

Electrical stunning is a method of simple stunning, so you’ll need to follow it with another operation to kill the animal once it’s unconscious.

When you carry out electrical stunning you must make sure that:

  • there’s good electrical contact with the animal
  • electrodes span the brain of the animal and can be adapted for the size of animal
  • the current is strong enough to make an animal unconscious until death

In addition you must:

  • kill the animal before it recovers consciousness
  • use at least the minimum currents for each species

Minimum currents for head-only electrical stunning

Species Minimum current
Cattle 6 months or older 1.28 amps (A)
Cattle younger than 6 months 1.25A
Sheep and goats 1.0A
Pigs 1.3A

Head-to-body electrical stunning

If you’re using electrodes on an animal’s head and body, you must use the following currents:

  • sheep and goats - 1A
  • pigs - 1.3A

You cannot use this method of simple stunning on cattle.

Monitor electrical stunning

For each animal you stun, equipment must be fitted with a device that displays key parameters such as:

  • voltage
  • current
  • length of exposure

The device must be clearly visible to staff carrying out stunning. Your standard operating procedure should state what parameters you need to record.

If the electrodes do not deliver the right current or voltage for the right amount of time, the device must give a warning that you can clearly see and hear.

You must keep all records for at least a year. Equipment purchased after 1 January 2013 - and all equipment from 8 December 2019 - must be fitted with a device that can record the parameters used for each animal stunned. These records must be kept for all equipment.

Captive bolt stunning

You must follow manufacturer’s instructions when using any device, including positioning and using the correct strength of cartridge.

Penetrative captive bolt

You can use penetrative captive bolt devices for simple stunning for all species.

You must apply the device in the proper position.

You must check the bolt has retracted to its full extent after each shot. If the bolt has not fully retracted, you must not use the device until it’s repaired

You must not shoot cattle (or any bovine animal, including bison and buffalo) in the back of the head.

Penetrative captive bolt: sheep and goats with horns

When stunning sheep and goats that have horns:

  • you can shoot the animal in the back of the head - you must aim the shot just behind the base of the horns and aim towards the mouth
  • you must bleed or kill an animal within 15 seconds of shooting it

Non-penetrative captive bolt

You can only use non-penetrative captive bolt devices for simple stunning on cattle, sheep, goats and deer (ruminants) under 10 kg. You must apply the device in the proper position.

Firearm stunning

You can use a firearm or shotgun to stun and kill an animal. You must use the correct power and calibre of cartridge for the type of animal.

Gas stunning

Gas stunning is a method of killing pigs. You must use a gas stunner to do this and follow the manufacturer’s instructions.

You must expose each pig to the gas for long enough to kill it and be able to:

  • visually monitor pigs in the gas stunner
  • access the pigs as quickly as possible
  • flush the stunner with air so you can enter the chamber

Gas stunners and their conveyors must:

  • minimise struggling or vocalisation
  • allow pigs to remain standing until they lose consciousness
  • get pigs to the point of maximum gas concentration within 30 seconds
  • have enough space for pigs to lie down without lying on each other, even when you’re operating at maximum capacity
  • have adequate lighting to allow pigs to see other pigs and their surroundings

Gas stunners and their conveyors must not injure or bruise pigs, or compress a pig’s chest.

Gas monitoring devices

Gas stunners must have a monitoring device that continuously measures and displays the gas concentration. You must make sure the device is clearly visible to staff.

Gas stunners installed since January 2013 must record the gas concentration. By December 2019, all gas stunners must record the gas concentration.

If the gas concentration falls below the correct level, the monitoring device must display a clear visible warning and sound an alarm.

You cannot allow a pig to go into or remain in the stunner if:

  • there’s a problem with the gas stunner
  • the alarm goes off
  • the gas concentration falls below the correct level

Keep records for gas stunners installed since January 2013

When using gas stunners installed since January 2013, you must record:

  • the gas concentration
  • the length of exposure to gas

You should keep the records for at least a year.

From 8 December 2019, this information must be recorded by all gas stunners.

Gas mixtures

You can use:

  • carbon dioxide at high concentration
  • carbon dioxide mixed with inert gases
  • inert gases

You must not allow gases to enter into the chamber or the location where animals are to be stunned and killed in a way that it could create burns or excitement by freezing or lack of humidity.

You must only stun pigs by gas if each pig is exposed to the gas for long enough to make sure it’s killed.

Carbon dioxide at high concentration

The minimum concentration is 80% carbon dioxide. Exposure of conscious pigs to the gas must lead to anoxia (loss of oxygen to the brain).

You must make sure that no pig enters the gas stunner if the carbon dioxide concentration by volume falls below 80%.

A pig must be conveyed to the maximum concentration of gas within 30 seconds of entering the stunner.

Carbon dioxide mixed with inert gases

Expose conscious pigs directly or progressively to a gas mixture containing up to 40% of carbon dioxide mixed with inert gases.

The maximum concentration is 40% carbon dioxide. Direct or progressive exposure of conscious pigs to the gas must lead to anoxia.

Inert gases

Expose conscious pigs directly or progressively to an inert gas mixture such as argon or nitrogen. This exposure must lead to the brain being deprived of oxygen (anoxia).

Bleeding animals

Bleeding is a killing method for cattle, sheep, goats, pigs and deer following simple stunning.

You must cut an animal’s 2 carotid arteries. Bleeding must:

  • begin immediately after simple stunning
  • be rapid
  • be profuse
  • be completed before the animal regains consciousness

If you bleed an animal after simple stunning, you must wait for the bleeding to stop and at least:

  • 30 seconds for cattle
  • 20 seconds for sheep, deer, pigs and goats

You have to confirm there are no signs of life before you can dress the animal.

Shackling or hoisting animals

Animals must be unconscious before they are shackled or hoisted. You must have a CoC to perform this operation.

Published 15 October 2015
Last updated 12 February 2019 + show all updates
  1. Added a paragraph about the Mandatory Use of CCTV in slaughterhouses regulations 2018

  2. First published.