Terrestrial Animal Health Code
Terrestrial Animal Health Code |
Slaughter of animals
General principles
Object
These recommendations address the need to ensure the welfare of food animals during pre-slaughter and slaughter processes, until they are dead.
These recommendations apply to the slaughter in slaughterhouses/abattoirs of the following domestic animals: cattle, buffalo, bison, sheep, goats, camelids, deer, horses, pigs, ratites, rabbits and poultry. Other animals, wherever they have been reared, and all animals slaughtered outside slaughterhouses/abattoirs should be managed to ensure that their transport, lairage, restraint and slaughter is carried out without causing undue stress to the animals; the principles underpinning these recommendations apply also to these animals.
Personnel
Persons engaged in the unloading, moving, lairage, care, restraint, stunning, slaughter and bleeding of animals play an important role in the welfare of those animals. For this reason, there should be a sufficient number of personnel, who should be patient, considerate, competent and familiar with the recommendations outlined in this chapter and their application within the national context.
Competence may be gained through formal training and/or practical experience. This competence should be demonstrated through a current certificate from the Competent Authority or from an independent body accredited by the Competent Authority.
The management of the slaughterhouses/abattoirs and the Veterinary Services should ensure that slaughterhouse/abattoir staff are competent and carry out their tasks in accordance with the principles of animal welfare.
Animal behaviour
Animal handlers should be experienced and competent in handling and moving farm livestock, and understand the behaviour patterns of animals and the underlying principles necessary to carry out their tasks.
The behaviour of individual animals or groups of animals will vary, depending on their breed, sex, temperament and age and the way in which they have been reared and handled. Despite these differences, the following behaviour patterns which are always present to some degree in domestic animals, should be taken into consideration in handling and moving the animals.
Most domestic livestock are kept in groups and follow a leader by instinct.
Animals which are likely to harm each other in a group situation should not be mixed at slaughterhouses/abattoirs.
The desire of some animals to control their personal space should be taken into account in designing facilities.
Domestic animals will try to escape if any person approaches closer than a certain distance. This critical distance, which defines the flight zone, varies among species and individuals of the same species, and depends upon previous contact with humans. Animals reared in close proximity to humans i.e. tame have a smaller flight zone, whereas those kept in free range or extensive systems may have flight zones which may vary from one metre to many metres. Animal handlers should avoid sudden penetration of the flight zone which may cause a panic reaction which could lead to aggression or attempted escape.
Animal handlers should use the point of balance at the animal’s shoulder to move animals, adopting a position behind the point of balance to move an animal forward and in front of the point of balance to move it backward.
Domestic animals have wide-angle vision but only have limited forward binocular vision and poor perception of depth. This means that they can detect objects and movements beside and behind them, but can only judge distances directly ahead.
Although most domestic animals have a highly sensitive sense of smell, they react in different ways to the smells of slaughterhouses/abattoirs. Smells which cause fear or other negative responses should be taken into consideration when managing animals.
Domestic animals can hear over a greater range of frequencies than humans and are more sensitive to higher frequencies. They tend to be alarmed by constant loud noise and by sudden noises, which may cause them to panic. Sensitivity to such noises should also be taken into account when handling animals.
Distractions and their removal
Distractions that may cause approaching animals to stop, baulk or turn back should be designed out from new facilities or removed from existing ones. Below are examples of common distractions and methods for eliminating them:
reflections on shiny metal or wet floors – move a lamp or change lighting;
dark entrances to chutes, races, stun boxes or conveyor restrainers – illuminate with indirect lighting which does not shine directly into the eyes of approaching animals or create areas of sharp contrast;
animals seeing moving people or equipment up ahead – install solid sides on chutes and races or install shields;
dead ends – avoid if possible by curving the passage, or make an illusory passage;
chains or other loose objects hanging in chutes or on fences – remove them;
uneven floors or a sudden drop in floor levels at the entrance to conveyor restrainers – avoid uneven floor surfaces or install a solid false floor under the restrainer to provide an illusion of a solid and continuous walking surface;
sounds of air hissing from pneumatic equipment – install silencers or use hydraulic equipment or vent high pressure to the external environment using flexible hosing;
clanging and banging of metal objects – install rubber stops on gates and other devices to reduce metal to metal contact;
air currents from fans or air curtains blowing into the face of animals – redirect or reposition equipment.
An example of a flight zone (cattle)
Handler movement pattern to move cattle forward
Moving and handling animals
General considerations
Each slaughterhouse/abattoir should have a dedicated plan for animal welfare. The purpose of such a plan should be to maintain good level of animal welfare at all stages of the handling of animals until they are killed. The plan should contain standard operating procedures for each step of animal handling as to ensure that animal welfare is properly implemented based on relevant indicators. It also should include specific corrective actions in case of specific risks, like power failures or other circumstances that could negatively affect the welfare of animals.
Animals should be transported to slaughter in a way that minimises adverse animal health and welfare outcomes, and the transport should be conducted in accordance with the OIE recommendations for the transportation of animals (Chapters 7.2. and 7.3.).
The following principles should apply to unloading animals, moving them into lairage pens, out of the lairage pens and up to the slaughter point:
The conditions of the animals should be assessed upon their arrival for any animal welfare and health problems.
Injured or sick animals, requiring immediate slaughter, should be killed humanely and without delay, in accordance with the recommendations of the OIE.
Animals should not be forced to move at a speed greater than their normal walking pace, in order to minimise injury through falling or slipping. Performance standards should be established where numerical scoring of the prevalence of animals slipping or falling is used to evaluate whether animal moving practices and/or facilities should be improved. In properly designed and constructed facilities with competent animal handlers, it should be possible to move 99% of animals without their falling.
Animals for slaughter should
not be forced to walk over the top of other animals.
Animals should be handled in such a way as
to avoid harm, distress or injury. Under no circumstances should animal handlers resort
to violent acts to move animals, such as crushing or breaking tails
of animals, grasping their eyes or pulling them by the ears. Animal handlers should
never apply an injurious object or irritant substance to animals
and especially not to sensitive areas such as eyes, mouth, ears,
anogenital region or belly. The throwing or dropping of animals,
or their lifting or dragging by body parts such as their tail, head, horns,
ears, limbs, wool, hair or feathers, should not be permitted. The
manual lifting of small animals is permissible.
When using goads and other aids, the following
principles should apply:
Animals that have little or no room to move should not be subjected to physical force or goads and other aids which compel movement. Electric goads and prods should only be used in extreme cases and not on a routine basis to move animals. The use and the power output should be restricted to that necessary to assist movement of an animal and only when an animal has a clear path ahead to move. Goads and other aids should not be used repeatedly if the animal fails to respond or move. In such cases it should be investigated whether some physical or other impediment is preventing the animal from moving.
The use of such devices should be limited
to battery-powered goads on the hindquarters of pigs and large ruminants,
and never on sensitive areas such as the eyes, mouth, ears, anogenital
region or belly. Such instruments should not be used on horses,
sheep and goats of any age, or on calves or piglets.
Useful and permitted goads include panels, flags, plastic paddles, flappers (a length of cane with a short strap of leather or canvas attached), plastic bags and metallic rattles; they should be used in a manner sufficient to encourage and direct movement of the animals without causing undue stress.
Painful procedures (including whipping, kicking, tail twisting, use of nose twitches, pressure on eyes, ears or external genitalia), or the use of goads or other aids which cause pain and suffering (including large sticks, sticks with sharp ends, lengths of metal piping, fencing wire or heavy leather belts), should not be used to move animals.
Excessive shouting at animals or making loud noises (e.g. through the cracking of whips) to encourage them to move should not occur, as such actions may make the animals agitated, leading to crowding or falling.
Animals should be grasped or lifted in a manner which avoids pain or suffering and physical damage (e.g. bruising, fractures, dislocations). In the case of quadrupeds, manual lifting by a person should only be used in young animals or small species, and in a manner appropriate to the species; grasping or lifting such animals only by their wool, hair, feathers, feet, neck, ears, tails, head, horns, limbs causing pain or suffering should not be permitted, except in an emergency where animal welfare or human safety may otherwise be compromised.
Conscious animals should not be thrown, dragged or dropped.
Performance standards should be established to evaluate the use of such instruments. Numerical scoring may be used to measure the percentage of animals moved with an electric instrument and the percentage of animals slipping or falling at a point in the slaughterhouse/abattoir. Any risk of compromising animal welfare, for example slippery floor, should be investigated immediately and the defect rectified to eliminate the problem. In addition to resource-based measures, outcome-based measures (e.g. bruises, lesions, behaviour, and mortality) should be used to monitor the level of welfare of the animals.
Specific considerations for poultry
Stocking density in transport crates should be optimum to suit climatic conditions and to maintain species-specific thermal comfort within containers.
Care is especially necessary during loading and unloading to avoid body parts being caught on crates, leading to dislocated or broken bones in conscious birds. Such injuries will adversely affect animal welfare, carcass and meat quality.
Modular systems that involve tipping of live birds are not conducive to maintaining good animal welfare. These systems, when used, should be incorporated with a mechanism to facilitate birds sliding out of the transport system, rather than being dropped or dumped on top of each other from heights of more than a metre.
Birds may get trapped or their wings or claws may get caught in the fixtures, mesh or holes in poorly designed, constructed or maintained transport systems. Under this situation, operators unloading birds should ensure gentle release of trapped birds.
Drawers in modular systems and crates should be stacked and de-stacked carefully so as to avoid injury to birds.
Birds should have sufficient space so that all can lie down at the same time without being on top of each other.
Birds with broken bones and/or dislocated joints should be humanely killed before being hung on shackles for processing.
The number of poultry arriving at the processing plant with broken bones and/or dislocated joints should be recorded in a manner that allows for verification. For poultry, the percentage of chickens with broken or dislocated wings should not exceed 2%, with less than 1% being the goal (under study).
Provisions relevant to animals delivered in containers
Containers in which animals are transported should be handled with care, and should not be thrown, dropped or knocked over. Where possible, they should be horizontal while being loaded and unloaded mechanically, and stacked to ensure ventilation. In any case they should be moved and stored in an upright position as indicated by specific marks.
Animals delivered in containers with perforated or flexible bottoms should be unloaded with particular care in order to avoid injury. Where appropriate, animals should be unloaded from the containers individually.
Animals which have been transported in containers should be slaughtered as soon as possible; mammals and ratites which are not taken directly upon arrival to the place of slaughter should have drinking water available to them from appropriate facilities at all times. Delivery of poultry for slaughter should be scheduled such that they are not deprived of water at the premises for longer than 12 hours. Animals which have not been slaughtered within 12 hours of their arrival should be fed, and should subsequently be given moderate amounts of food at appropriate intervals.
Provisions relevant to restraining and containing animals
Provisions relevant to restraining animals for stunning or slaughter without stunning, to help maintain animal welfare, include:
provision of a non-slippery floor;
avoidance of excessive pressure applied by restraining equipment that causes struggling or vocalisation in animals;
equipment engineered to reduce noise of air hissing and clanging metal;
absence of sharp edges in restraining equipment that would harm animals;
avoidance of jerking or sudden movement of restraining device.
Methods of restraint causing avoidable suffering should not be used in conscious animals because they cause severe pain and stress:
suspending or hoisting animals (other than poultry) by the feet or legs;
indiscriminate and inappropriate use of stunning equipment;
mechanical clamping of the legs or feet of the animals (other than shackles used in poultry and ostriches) as the sole method of restraint;
breaking legs, cutting leg tendons or blinding animals in order to immobilise them;
severing the spinal cord, for example using a puntilla or dagger, to immobilise animals using electric currents to immobilise animals, except for proper stunning.
Lairage design and construction
General considerations
The lairage should be designed and constructed to hold an appropriate number of animals in relation to the throughput rate of the slaughterhouse/abattoir without compromising the welfare of the animals.
In order to permit operations to be conducted as smoothly and efficiently as possible without injury or undue stress to the animals, the lairage should be designed and constructed so as to allow the animals to move freely in the required direction, using their behavioural characteristics and without undue penetration of their flight zone.
The following recommendations may help to achieve this.
Design of lairage
The lairage should be designed to allow a one-way flow of animals from unloading to the point of slaughter, with a minimum number of abrupt corners to negotiate.
In red meat slaughterhouses/abattoirs, pens, passageways and races should be arranged in such a way as to permit inspection of animals at any time, and to permit the removal of sick or injured animals when considered to be appropriate, for which separate appropriate accommodation should be provided.
Each animal should have room to stand up and lie down and, when confined in a pen, to turn around, except where the animal is reasonably restrained for safety reasons (e.g. fractious bulls). Fractious animals should be slaughtered as soon as possible after arrival at the slaughterhouse/abattoir to avoid welfare problems. The lairage should have sufficient accommodation for the number of animals intended to be held. Drinking water should always be available to the animals, and the method of delivery should be appropriate to the type of animal held. Troughs should be designed and installed in such a way as to minimise the risk of fouling by faeces, without introducing risk of bruising and injury in animals, and should not hinder the movement of animals.
Holding pens should be designed to allow as many animals as possible to stand or lie down against a wall. Where feed troughs are provided, they should be sufficient in number and feeding space to allow adequate access of all animals to feed. The feed trough should not hinder the movement of animals.
Where tethers, ties or individual stalls are used, these should be designed so as not to cause injury or distress to the animals and should also allow the animals to stand, lie down and access any food or water that may need to be provided.
Passageways and races should be either straight or consistently curved, as appropriate to the animal species. Passageways and races should have solid sides, but when there is a double race, the shared partition should allow adjacent animals to see each other. For pigs and sheep, passageways should be wide enough to enable two or more animals to walk side by side for as long as possible. At the point where passageways are reduced in width, this should be done by a means which prevents excessive bunching of the animals.
Animal handlers should be positioned alongside races and passageways on the inside radius of any curve, to take advantage of the natural tendency of animals to circle an intruder. Where one-way gates are used, they should be of a design which avoids bruising. Races should be horizontal but where there is a slope, they should be constructed to allow the free movement of animals without injury.
In slaughterhouses/abattoirs with high throughput, there should be a waiting pen, with a level floor and solid sides, between the holding pens and the race leading to the point of stunning or slaughter, to ensure a steady supply of animals for stunning or slaughter and to avoid having animal handlers trying to rush animals from the holding pens. The waiting pen should preferably be circular, but in any case, so designed that animals cannot be trapped or trampled.
Ramps or lifts should be used for the loading and unloading of animals where there is a difference in height or a gap between the floor of the vehicle and the unloading area. Unloading ramps should be designed and constructed so as to permit animals to be unloaded from vehicles on the level or at the minimum gradient achievable. Lateral side protection should be available to prevent animals escaping or falling. They should be well drained, with secure footholds and adjustable to facilitate easy movement of animals without causing distress or injury.
Construction of lairage
Lairages should
be constructed and maintained so as to provide protection from unfavourable
climatic conditions, using strong and resistant materials such as
concrete and metal which has been treated to prevent corrosion.
Surfaces should be easy to clean. There should be no sharp edges
or protuberances which may injure the animals.
Floors should be well drained and not slippery;
they should not cause injury to the feet of the animals. Where necessary,
floors should be insulated or provided with appropriate bedding.
Drainage grids should be placed at the sides of pens and passageways
and not where animals would have to cross them. Discontinuities
or changes in floor, wall or gate colours, patterns or texture which
could cause baulking in the movement of animals should be avoided.
Lairages should
be provided with adequate lighting, but care should be taken to
avoid harsh lights and shadows, which frighten the animals or affect
their movement. The fact that animals will move more readily from
a darker area into a well-lit area might be exploited by providing
for lighting that can be regulated accordingly.
Lairages should
be adequately ventilated to ensure that waste gases (e.g. ammonia)
do not build up and that draughts at animal height are minimised.
Ventilation should be able to cope with the range of expected climatic
conditions and the number of animals the lairage will
be expected to hold.
Care should be taken to protect the animals
from excessively or potentially disturbing noises, for example by avoiding
the use of noisy hydraulic or pneumatic equipment, and muffling
noisy metal equipment by the use of suitable padding, or by minimising
the transmission of such noises to the areas where animals are held
and slaughtered.
Where animals are kept in outdoor lairages without natural shelter or shade, they should be protected from the effects of adverse weather conditions.
Care of animals in lairages
Animals in lairages should be cared for in accordance with the following recommendations:
As far as possible, established groups of animals should be kept together and each animal should have enough space to stand up, lie down and turn around. Animals hostile to each other should be separated.
Where tethers, ties or individual stalls are used, they should allow animals to stand up and lie down without causing injury or distress.
Where bedding is provided, it should be maintained in a condition that minimises risks to the health and safety of the animals, and sufficient bedding should be used so that animals do not become soiled with manure.
Animals should be kept securely in the lairage, and care should be taken to prevent them from escaping and from predators.
Suitable drinking water should be available to the animals on their arrival and at all times to animals in lairages unless they are to be slaughtered without delay.
Waiting time should be minimised and should not exceed 12 hours. If animals are not to be slaughtered within this period, suitable feed should be available to the animals on arrival and at intervals appropriate to the species. Unweaned animals should be slaughtered as soon as possible.
In order to prevent heat stress, animals subjected to high temperatures, particularly pigs and poultry, should be cooled by the use of water sprays, fans or other suitable means. However, the potential for water sprays to reduce the ability of animals to thermoregulate (especially poultry) should be considered in any decision to use water sprays. The risk of animals being exposed to very cold temperatures or sudden extreme temperature changes should also be considered.
The lairage area should be well lit in order to enable the animals to see clearly without being dazzled. During the night, the lights should be dimmed. Lighting should also be adequate to permit inspection of all animals. Subdued lighting, and for example blue light, may be useful in poultrylairages in helping to calm birds.
The condition and state of health of the
animals in a lairage should
be inspected at least every morning and evening by a veterinarian or,
under the veterinarian’s
responsibility, by another competent person, such as an animal handler.
Animals which are sick, weak, injured or showing visible signs of
distress should be separated, and veterinary advice should be sought
immediately regarding treatment or the animals should be humanely
killed immediately if necessary.
Lactating dairy animals should be slaughtered
as soon as possible. Dairy animals with obvious udder distension should
be milked to minimise udder discomfort.
Animals which have given birth during the journey or in the lairage should be slaughtered as soon as possible or provided with conditions which are appropriate for suckling for their welfare and the welfare of the newborn. Under normal circumstances, animals which are expected to give birth during a journey should not be transported.
Animals with horns, antlers or tusks capable of injuring other animals, if aggressive, should be penned separately.
Poultry awaiting slaughter should be protected from adverse weather conditions and provided with adequate ventilation.
Poultry in transport containers should be examined at the time of arrival. Containers should be stacked with sufficient space between the stacks to facilitate inspection of birds and air movement.
Forced ventilation or other cooling systems may be necessary under certain conditions to avoid buildup of temperature and humidity. Temperature and humidity should be monitored at appropriate intervals.
Recommendations for specific species are described in detail in Articles 7.5.5. to 7.5.9.
Management of foetuses during slaughter of pregnant animals
Under normal circumstances, pregnant animals that would be in the final 10% of their gestation period at the planned time of unloading at the slaughterhouse/abattoir should be neither transported nor slaughtered. If such an event occurs, an animal handler should ensure that females are handled separately, and the specific procedures described below are applied. In all cases, the welfare of foetuses and dams during slaughter should be safeguarded.
Foetuses should not be removed from the uterus
sooner than 5 minutes after the maternal neck or chest cut, to ensure absence
of consciousness. A foetal heartbeat will usually still be present
and foetal movements may occur at this stage, but these are only
a cause for concern if the exposed foetus successfully breathes
air.
If a live mature foetus is removed from the uterus,
it should be prevented from inflating its lungs and breathing air
(e.g. by clamping the trachea).
When uterine, placental or foetal tissues, including foetal blood, are not to be collected as part of the post-slaughter processing of pregnant animals, all foetuses should be left inside the unopened uterus until they are dead. When uterine, placental or foetal tissues are to be collected, where practical, foetuses should not be removed from the uterus until at least 15–20 minutes after the maternal neck or chest cut.
If there is any doubt about consciousness, the foetus should be killed with a captive bolt of appropriate size or a blow to the head with a suitable blunt instrument.
The above recommendations do not refer to foetal rescue. Foetal rescue, the practice of attempting to revive foetuses found alive at the evisceration of the dam, should not be attempted during normal commercial slaughter as it may lead to serious welfare complications in the newborn animal. These include impaired brain function resulting from oxygen shortage before rescue is completed, compromised breathing and body heat production because of foetal immaturity, and an increased incidence of infections due to a lack of colostrum.
Summary analysis of handling and restraining methods and the associated animal welfare issues
| Presentation of animals | Specific procedure | Specific purpose | Animal welfare concerns/ implications | Key animal welfare requirements | Applicable species | |
| No restraint | Animals are grouped | Group container | Gas stunning | Specific procedure is suitable only for gas stunning | Competent animal handlers in lairage; facilities; stocking density | Pigs, poultry |
| In the field | Free bullet | Inaccurate targeting and inappropriate ballistics not achieving outright kill with first shot | Operator competence | Deer | ||
| Group stunning pen | Head-only electrical Captive bolt | Uncontrolled movement of animals impedes use of hand operated electrical and mechanical stunning methods | Competent animal handlers in lairage and at stunning point | Pigs, sheep, goats, calves | ||
| Individual animal confinement | Stunning pen/box | Electrical and mechanical stunning methods | Loading of animal; accuracy of stunning method, slippery floor and animal falling down | Competent animal handlers | Cattle, buffalo, sheep, goats, horses, pigs, deer, camelids, ratites | |
| Restraining methods | Head restraint, upright | Halter/ head collar/bridle | Captive bolt Free bullet | Suitable for halter-trained animals; stress in untrained animals | Competent animal handlers | Cattle, buffalo, horses, camelids |
| Restraining methods (contd) | Head restraint, upright | Neck yoke | Captive bolt Electrical-head only Free bullet Slaughter without stunning | Stress of loading and neck capture; stress of prolonged restraint, horn configuration; unsuitable for fast line speeds, animals struggling and falling due to slippery floor, excessive pressure | Equipment; competent animal handlers, prompt stunning or slaughter | Cattle |
| Leg restraint | Single leg tied in flexion (animal standing on 3 legs) | Captive bolt Free bullet | Ineffective control of animal movement, misdirected shots | Competent animal handler | Breeding pigs (boars and sows) | |
| Upright restraint | Beak holding | Captive bolt Electrical-head only | Stress of capture | Sufficient competent animal handlers | Ostriches | |
| Upright restraint | Head restraint in electrical stunning box | Electrical-head only | Stress of capture and positioning | Competent animal handler | Ostriches | |
| Holding body upright-manual | Manual restraint | Captive bolt Electrical-head only Slaughter without stunning | Stress of capture and restraint; accuracy
of stunning/ slaughter | Competent animal handlers | Sheep, goats, calves, ratites, small camelids, poultry | |
| Holding body upright mechanical | Mechanical clamp/crush/ squeeze/ V-restrainer (static) | Captive bolt Electrical methods Slaughter without stunning | Loading of animal and overriding; excessive pressure | Proper design and operation of equipment | Cattle, buffalo, sheep, goats, deer, pigs, ostriches | |
| Lateral restraint–manual or mechanical | Restrainer/ cradle/crush | Slaughter without stunning | Stress of restraint | Competent animal handlers | Sheep, goats, calves, camelids, cattle | |
| Upright restraint mechanical | Mechanical straddle (static) | Slaughter without stunning Electrical methods Captive bolt | Loading of animal and overriding | Competent animal handlers | Cattle, sheep, goats, pigs | |
| Upright restraint–manual or mechanical | Wing shackling | Electrical | Excessive tension applied prior to stunning | Competent animal handlers | Ostriches | |
| Restraining and /or conveying methods | Mechanical –upright | V–restrainer | Electrical methods Captive bolt Slaughter without stunning | Loading of animal and overriding; excessive pressure, size mismatch between restrainer and animal | Proper design and operation of equipment | Cattle, calves, sheep, goats, pigs |
| Mechanical straddle–band restrainer (moving) | Electrical methods Captive bolt Slaughter without stunning | Loading of animal and overriding, size mismatch between restrainer and animal | Competent animal handlers, proper design and layout of restraint | Cattle, calves, sheep, goats, pigs | ||
| Flat bed/deck Tipped out of containers on to conveyors | Presentation of birds for shackling
prior to electrical stunning Gas stunning | Stress and injury due to tipping
in dump-module systems height of tipping conscious poultry broken bones and dislocations | Proper design and operation of equipment | Poultry | ||
| Restraining and /or conveying methods (contd) | Suspension and/or inversion | Poultry shackle | Electrical stunning Slaughter without stunning | Inversion stress; pain from compression on leg bones | Competent animal handlers; proper design and operation of equipment | Poultry |
| Cone | Electrical – head-only Captive bolt Slaughter without stunning | Inversion stress | Competent animal handlers; proper design and operation of equipment | Poultry | ||
| Upright restraint | Mechanical leg clamping | Electrical – head-only | Stress of resisting restraint in ostriches | Competent animal handlers; proper equipment design and operation | Ostriches | |
| Restraining by inversion | Rotating box | Fixed side(s) (e.g. Weinberg pen) | Slaughter without stunning | Inversion stress; stress of resisting restraint, prolonged restraint, inhalation
of blood and ingesta Keep restraint as brief as possible | Proper design and operation of equipment | Cattle |
| Compressible side(s) | Slaughter without stunning | Inversion stress, stress of resisting restraint, prolonged restraint Preferable to rotating box with fixed sides Keep restraint as brief as possible | Proper design and operation of equipment | Cattle | ||
| Body restraint | Casting/ hobbling | Manual | Mechanical stunning methods Slaughter without stunning | Stress of resisting restraint;
animal temperament; bruising. Keep restraint as short as possible | Competent animal handlers | Sheep, goats, calves, small camelids, pigs |
| Rope casting | Mechanical stunning methods Slaughter without stunning | Stress of resisting restraint; prolonged restraint,
animal temperament; bruising Keep restraint as short as possible | Competent animal handlers | Cattle, camelids | ||
| Leg restraints | Tying of 3 or 4 legs | Mechanical stunning methods Slaughter without stunning | Stress of resisting restraint; prolonged restraint,
animal temperament; bruising Keep restraint as short as possible | Competent animal handlers | Sheep, goats, small camelids, pigs |
Stunning methods
General considerations
The competence of the operators, and the appropriateness,
and effectiveness of the method used for stunning and the
maintenance of the equipment are the responsibility of the management
of the slaughterhouse/abattoir,
and should be checked regularly by a Competent Authority.
Persons carrying out stunning should be properly trained and competent, and should ensure that:
the animal is adequately restrained;
animals in restraint are
stunned as soon as possible;
the equipment used for stunning is
maintained and operated properly in accordance with the manufacturer's recommendations,
in particular with regard to the species and size of the animal;
the equipment is applied correctly;
stunned animals are bled out (slaughtered)
as soon as possible;
animals are not stunned when slaughter is
likely to be delayed; and
backup stunning devices
are available for immediate use if the primary method of stunning fails.
Provision of a manual inspection area and simple intervention like
captive bolt or cervical dislocation for poultry would
help prevent potential welfare problems.
In addition, such persons should be able to recognise when an animal is not correctly stunned and should take appropriate action.
Mechanical stunning
A mechanical device should be applied usually
to the front of the head and perpendicular to the bone surface.
For a more detailed explanation on the different methods for mechanical stunning,
see Chapter 7.6. and
Articles 7.6.6., 7.6.7. and 7.6.8.
Signs of correct stunning using a mechanical device are as follows:
the animal collapses immediately and does not attempt to stand up;
the body and muscles of the animal become tonic (rigid) immediately after the shot;
normal rhythmic breathing stops; and
the eyelid is open with the eyeball facing
straight ahead and is not rotated.
Captive bolts powered by cartridges, compressed air or spring can be used for poultry. The optimum position for poultry species is at a right angle to the frontal surface. Firing of a captive bolt in accordance with the manufacturers’ instructions should lead to immediate destruction of the skull and the brain and, as a result, immediate death.
Electrical stunning
General considerations
An electrical device should be applied to the animal in accordance with the following recommendations.
Electrodes should be designed, constructed, maintained and cleaned regularly to ensure that the flow of current is optimal and in accordance with manufacturing specifications. They should be placed so that they span the brain. The application of electrical currents which bypass the brain is unacceptable unless the animal has been stunned. The use of a single current leg-to-leg is unacceptable as a stunning method.
If, in addition, it is intended to cause cardiac
arrest, the electrodes should either span the brain and immediately
thereafter the heart, on the condition that it has been ascertained
that the animal is adequately stunned, or span brain and heart simultaneously.
Electrical stunning equipment
should not be applied on animals as a means of guidance, movement, restraint or
immobilisation, and shall not deliver any shock to the animal before
the actual stunning or killing.
Electrical stunning apparatus
should be tested prior to application on animals using appropriate
resistors or dummy loads to ensure the power output is adequate
to stun animals.
The electrical stunning apparatus should incorporate a device that monitors and displays voltage (true RMS) and the applied current (true RMS) and that such devices are regularly calibrated at least annually.
Appropriate measures, such as removing excess
wool or wetting the skin only at the point of contact, can be taken
to minimise impedance of the skin and facilitate effective stunning.
The stunning apparatus
should be appropriate for the species. Apparatus for electrical stunning should
be provided with adequate power to achieve continuously the minimum
current level recommended for stunning as
indicated in the table below.
In all cases, the correct current level shall be attained within one second of the initiation of stun and maintained at least for between one and three seconds and in accordance with the manufacturer's instructions. Minimum current levels for head-only stunning are shown in the following table.
| Species | Minimum current levels for head-only stunning |
| Cattle | 1.5 amps |
| Calves (bovines of less than 6 month of age) | 1.0 amps |
| Pigs | 1.25 amps |
| Sheep and goats | 1.0 amps |
| Lambs | 0.7 amps |
| Ostriches | 0.4 amps |
Electrical stunning of birds using a waterbath
There should be no sharp bends or steep gradients
in the shackle line and the shackle line should be as short as possible
consistent with achieving acceptable line speeds, and ensuring that
birds have settled by the time they reach the waterbath. A breast
comforter can be used effectively to reduce wing flapping and calm
birds. The angle at which the shackle line approaches the entrance
to the waterbath, and the design of the entrance to the waterbath,
and the draining of excess 'live' water from the bath are all important
considerations in ensuring birds are calm as they enter the bath,
do not flap their wings, and do not receive pre-stun electric shocks.
In the case of birds suspended on a moving line,
measures should be taken to ensure that the birds are not wing flapping
at the entrance of the stunner. The birds should be secure in their
shackle, but there should not be undue pressure on their shanks.
The shackle size should be appropriate to fit the size of the shanks (metatarsal
bones) of birds.
Birds should be hung on shackles by both legs.
Birds with dislocated or broken legs or wings
should be humanely killed rather than shackled.
The duration between hanging on shackles and stunning should be kept to the minimum. In any event, the time between shackling and stunning should not exceed one minute.
Waterbaths for poultry should be adequate in size and depth for the type of bird being slaughtered, and their height should be adjustable to allow for the head of each bird to be immersed. The electrode immersed in the bath should extend the full length of the waterbath. Birds should be immersed in the bath up to the base of their wings.
The waterbath should be designed and maintained
in such a way that when the shackles pass over the water, they are
in continuous contact with the earthed rubbing bar.
The control box for the waterbath stunner should
incorporate an ammeter which displays the total current flowing
through the birds.
The shackle-to-leg contact should be wetted preferably
before the birds are inserted in the shackles. In order to improve
the electrical conductivity of the water, it is recommended that
salt be added in the waterbath as necessary. Additional salt should
be added regularly as a solution to maintain suitable constant concentrations
in the waterbath.
Using waterbaths, birds are stunned in groups
and different birds will have different impedances. The voltage should
be adjusted so that the total current is the required current per
bird as shown in the table hereafter, multiplied by the number of
birds in the waterbath at the same time. The following values have
been found to be satisfactory when employing a 50 Hertz sinusoidal
alternating current.
Birds should receive the current for at least
4 seconds.
While a lower current may also be satisfactory,
the current shall in any case be such as to ensure that unconsciousness
occurs immediately and lasts until the bird has been killed by cardiac
arrest or by bleeding. When higher electrical frequencies are used,
higher currents may be required.
Every effort shall be made to ensure that no
conscious or live birds enter the scalding tank.
In the case of automatic systems, until fail-safe
systems of stunning and
bleeding have been introduced, a manual back-up system should be
in place to ensure that any birds which have missed the waterbath
stunner and/or the automatic neck-cutter are immediately stunned
and/or killed immediately, and they are dead before entering scald
tank.
To lessen the number of birds that have not been
effectively stunned reaching neck cutters, steps should be taken
to ensure that small birds do not go on the line amongst bigger
birds and that these small birds are stunned separately. The height
of the waterbath stunner should be adjusted in accordance with the
size of birds to ensure even the small birds are immersed in the
waterbath up to the base of the wings.
Waterbath stunning equipment
should be fitted with a device which displays and records the details
of the electrical key parameter.
Minimum current for stunningpoultry when using 50Hz is as follows:
| Species | Current (milliamperes per bird) |
| Broilers | 100 |
| Layers (spent hens) | 100 |
| Turkeys | 150 |
| Ducks and geese | 130 |
Minimum current for stunningpoultry when using high frequencies is as follows:
| Frequency (Hz) | Minimum current (milliamperes per bird) | |
| Chickens | Turkeys | |
| From 50 to 200 Hz | 100 mA | 250 mA |
| From 200 to 400 Hz | 150 mA | 400 mA |
| From 400 to 1500 Hz | 200 mA | 400 mA |
Gas stunning (under study)
Stunning of pigs by exposure to carbon dioxide (CO2)
The concentration of CO2 for stunning should be preferably 90% by volume but in any case no less than 80% by volume. After entering the stunning chamber, the animals should be conveyed to the point of maximum concentration of the gas as rapidly as possible and be kept until they are dead or brought into a state of insensibility which lasts until death occur due to bleeding. Ideally, pigs should be exposed to this concentration of CO2 for 3 minutes. Sticking should occur as soon as possible after exit from the gas chamber.
In any case, the concentration of the gas should be such that it minimises as far as possible all stress of the animal prior to loss of consciousness.
The chamber in which animals are exposed to CO2 and the equipment used for conveying them through it shall be designed, constructed and maintained in such a way as to avoid injury or unnecessary stress to the animals. The animal density within the chamber should be such to avoid stacking animals on top of each other.
The conveyor and the chamber shall be adequately lit to allow the animals to see their surroundings and, if possible, each other.
It should be possible to inspect the CO2 chamber whilst it is in use, and to have access to the animals in emergency cases.
The chamber shall be equipped to continuously measure and display register at the point of stunning the CO2 concentration and the time of exposure, and to give a clearly visible and audible warning if the concentration of CO2 falls below the required level.
Emergency stunning equipment should be available at the point of exit from the stunning chamber and used on any pigs that do not appear to be completely stunned.
Inert gas mixtures for stunning pigs
Inhalation of high concentration of carbon dioxide is aversive and can be distressing to animals. Therefore, the use of non-aversive gas mixtures is being developed.
Such gas mixtures include:
a maximum of 2% by volume of oxygen in argon, nitrogen or other inert gases, or
to a maximum of 30% by volume of carbon dioxide and a maximum of 2% by volume of oxygen in mixtures with carbon dioxide and argon, nitrogen or other inert gases.
Exposure time to the gas mixtures should be sufficient to ensure that no pigs regain consciousness before death supervenes through bleeding or cardiac arrest is induced.
Gas stunning of poultry
The main objective of gas stunning is to avoid the pain and suffering associated with shackling conscious poultry under waterbath stunning and killing systems. Therefore, gas stunning should be limited to birds contained in crates or on conveyors only. The gas mixture should be non-aversive to poultry.
Live poultry contained within transport modules or crates may be exposed to gradually increasing concentrations of CO2 until the birds are properly stunned. No bird should recover consciousness during bleeding.
Gas stunning of poultry in their transport containers will eliminate the need for live birds' handling at the processing plant and all the problems associated with the electrical stunning. Gas stunning of poultry on a conveyor eliminates the problems associated with the electrical waterbath stunning.
Live poultry should be conveyed into the gas mixtures either in transport crates or on conveyor belts.
The following gas procedures have been properly documented for chickens and turkeys but do not necessarily apply for other domestic birds. In any case the procedure should be designed as to ensure that all animals are properly stunned without unnecessary suffering. Some monitoring points for gas stunning could be the following:
ensure smooth entry and passage of crates or birds through the system;
avoid crowding of birds in crates or conveyors;
monitor and maintain gas concentrations continuously during operation;
provide visible and audible alarm systems if gas concentrations are inappropriate to the species;
calibrate gas monitors and maintain verifiable records;
ensure that duration of exposure is adequate to prevent recovery of consciousness;
make provision to monitor and deal with recovery of consciousness;
ensure that blood vessels are cut to induce death in unconscious birds;
ensure that all birds are dead before entering scalding tank;
provide emergency procedures in the event of system failure.
Gas mixtures used for stunning poultry include:
a minimum of 2 minutes exposure to 40% carbon dioxide, 30% oxygen and 30% nitrogen, followed by a minimum of one minute exposure to 80% carbon dioxide in air; or
a minimum of 2 minutes exposure to any mixture of argon, nitrogen or other inert gases with atmospheric air and carbon dioxide, provided that the carbon dioxide concentration does not exceed 30% by volume and the residual oxygen concentration does not exceed 2% by volume; or
a minimum of 2 minutes exposure to argon, nitrogen, other inert gases or any mixture of these gases in atmospheric air with a maximum of 2% residual oxygen by volume; or
a minimum of 2 minutes exposure to a minimum of 55% carbon dioxide in air; or
a minimum of one minute exposure to 30% carbon dioxide in air, followed by a minimum of one minute exposure to at least 60% carbon dioxide in air.
Requirements for effective use are as follows:
Compressed gases should be vaporised prior to administration into the chamber and should be at room temperature to prevent any thermal shock; under no circumstances, should solid gases with freezing temperatures enter the chamber.
Gas mixtures should be humidified.
Appropriate gas concentrations of oxygen and carbon dioxide should be monitored and displayed continuously at the level of the birds inside the chamber to ensure that anoxia ensues.
Under no circumstances, should birds exposed to gas mixtures be allowed to regain consciousness. If necessary, the exposure time should be extended.
Bleeding
From the point of view of animal welfare, animals which are stunned with a reversible method should be bled without delay. Maximum stun-stick interval depends on the parameters of the stunning method applied, the species concerned and the bleeding method used (full cut or chest stick when possible). As a consequence, depending on those factors, the slaughterhouse/abattoir operator should set up a maximum stun-stick interval that ensures that no animals recover consciousness during bleeding. In any case the following time limits should be applied.
| Stunning method | Maximum–stun stick interval |
|---|---|
| Electrical methods and non-penetrating captive bolt | 20 seconds |
| CO2 | 60 seconds (after leaving the chamber) |
All animals should be bled out by incising both carotid arteries, or the vessels from which they arise (e.g. chest stick). However, when the stunning method used causes cardiac arrest, the incision of all of these vessels is not necessary from the point of view of animal welfare.
It should be possible for staff to observe, inspect and access the animals throughout the bleeding period. Any animal showing signs of recovering consciousness should be re-stunned.
After incision of the blood vessels, no scalding carcass treatment or dressing procedures should be performed on the animals for at least 30 seconds, or in any case until all brain-stem reflexes have ceased.
Summary analysis of stunning methods and the associated animal welfare issues
| Method | Specific method | Animal welfare concerns/ implications | Key animal welfare requirements applicable | Species | Comment |
| Mechanical | Free bullet | In accurate targeting and inappropriate ballistics | Operator competence; achieving outright kill with first shot | Cattle, calves, buffalo, deer, horses, pigs (boars and sows) | Personnel safety |
| Captive bolt – penetrating | Inaccurate targeting, velocity and diameter of bolt | Competent operation and maintenance of equipment; restraint; accuracy | Cattle, calves, buffalo, sheep, goats, deer, horses, pigs, camelids, ratites, poultry | (Unsuitable for specimen collection from
TSE suspects). A back-up gun should be available in the event of an ineffective shot | |
| Captive bolt – non-penetrating | Inaccurate targeting, velocity of bolt, potentially higher failure rate than penetrating captive bolt | Competent operation and maintenance of equipment; restraint; accuracy | Cattle, calves, sheep, goats, deer, pigs, camelids, ratites, poultry | Presently available devices are not recommended for young bulls and animals with thick skull. This method should only be used for cattle and sheep when alternative methods are not available. | |
| Manual percussive blow | Inaccurate targeting; insufficient power; size of instrument | Competent animal handlers; restraint; accuracy. Not recommended for general use | Young and small mammals, ostriches and poultry | Mechanical devices potentially more reliable. Where manual percussive blow is used, unconsciousness should be achieved with single sharp blow delivered to central skull bones | |
| Electrical | Split application: 1. across head then head to chest; 2. across head then across chest | Accidental pre-stun electric shocks; electrode positioning; application of a current to the body while animal conscious; inadequate current and voltage | Competent operation and maintenance of equipment; restraint; accuracy | Cattle, calves, sheep, goats and pigs, ratites and poultry | Systems involving repeated application of head-only or head-to-leg with short current durations (<1 second) in the first application should not be used. |
| Single application: 1. head only; 2. head to body; 3. head to leg | Accidental pre-stun electric shocks; inadequate current and voltage; wrong electrode positioning; recovery of consciousness | Competent operation and maintenance of equipment; restraint; accuracy | Cattle, calves, sheep, goats, pigs, ratites, poultry | ||
| Waterbath | Restraint, accidental pre-stun electric shocks; inadequate current and voltage; recovery of consciousness | Competent operation and maintenance of equipment | Poultry only | ||
| Gaseous | CO2 air/O2 mixture; CO2 inert gas mixture | Aversiveness of high CO2; respiratory distress; inadequate exposure | Concentration; duration of exposure; design, maintenance and operation of equipment; stocking density management | Pigs, poultry | |
| Method | Specific method | Animal welfare concerns/ implications | Key animal welfare requirements applicable | Species | Comment |
| Gaseous (contd) | Inert gases | Recovery of consciousness | Concentration; duration of exposure; design, maintenance and operation of equipment; density management | Pigs, poultry |
Summary analysis of slaughter methods and the associated animal welfare issues
| Slaughter methods | Specific method | Animal welfare concerns/ implications | Key requirements | Species | Comments |
| Bleeding out by severance of blood vessels in the neck without stunning | Full frontal cutting across the throat | Failure to cut both common carotid arteries; occlusion of cut arteries; pain during and after the cut | High level of operator competency.
A very sharp blade or knife of sufficient length so that the point
of the knife remains outside the incision during the cut; the point
of the knife should not be used to make the incision. The incision should not close over the knife during the throat cut. | Cattle, buffalo, horses, camelids, sheep, goats, poultry, ratites | No further procedure should be
carried out before the bleeding out is completed (i.e. at least
30 seconds for mammals). The practice to remove hypothetical blood clots just after the bleeding should be discouraged since this may increase animal suffering. |
| Bleeding with prior stunning | Full frontal cutting across the throat | Failure to cut both common carotid arteries; occlusion of cut arteries; pain during and after the cut. | A very sharp blade or knife of sufficient length so that the point of the knife remains outside the incision during the cut; the point of the knife should not be used to make the incision. The incision should not close over the knife during the throat cut. | Cattle, buffalo, horses, camelids, sheep, goats | |
| Neck stab followed by forward cut | Ineffective stunning; failure
to cut both common carotid arteries; impaired blood flow; delay in cutting after reversible stunning | Prompt and accurate cutting | Camelids, sheep, goats, poultry, ratites | ||
| Neck stab alone | Ineffective stunning; failure to cut both common carotid arteries; impaired blood flow; delay in cutting after reversible stunning | Prompt and accurate cutting | Camelids, sheep, goats, poultry, ratites | ||
| Chest stick into major arteries or hollow-tube knife into heart | Ineffective stunning; inadequate size of stick wound inadequate length of sticking knife; delay in sticking after reversible stunning | Prompt and accurate sticking | Cattle, sheep, goats, pigs | ||
| Bleeding with prior stunning (contd) | Neck skin cut followed by severance of vessels in the neck | Ineffective stunning; inadequate size of stick wound; inadequate length of sticking knife; delay in sticking after reversible stunning | Prompt and accurate cutting of vessels | Cattle | |
| Automated mechanical cutting | Ineffective stunning; failure
to cut and misplaced cuts. Recovery of consciousness following reversible stunning systems | Design, maintenance and operation of equipment; accuracy of cut; manual back-up | Poultry only | ||
| Manual neck cut on one side | Ineffective stunning; recovery of consciousness following reversible stunning systems | Prior non-reversible stunning | Poultry only | N.B. slow induction of unconsciousness under slaughter without stunning | |
| Oral cut | Ineffective stunning; recovery of consciousness following reversible stunning systems | Prior non-reversible stunning | Poultry only | N.B. slow induction of unconsciousness in non-stun systems | |
| Other methods without stunning | Decapitation with a sharp knife | Pain due to loss of consciousness not being immediate | Sheep, goats, poultry | This method is only applicable to Jhatka slaughter | |
| Manual neck dislocation and decapitation | Pain due to loss of consciousness not being immediate; difficult to achieve in large birds | Neck dislocation should be performed in one stretch to sever the spinal cord | Poultry only | Slaughter by neck dislocation should be performed in one stretch to sever the spinal cord. Acceptable only when slaughtering small numbers of small birds. | |
| Cardiac arrest in a waterbath electric stunner | Bleeding by evisceration | Induction of cardiac arrest | Quail | ||
| Bleeding by neck cutting | Poultry |
Methods, procedures or practices unacceptable
on animal welfare grounds
The restraining methods which work through electro-immobilisation or immobilisation by injury such as breaking legs, leg tendon cutting, and severing the spinal cord (e.g. using a puntilla or dagger) cause severe pain and stress in animals. Those methods are not acceptable in any species.
The use of the electrical stunning method with a single application leg to leg is ineffective and unacceptable in any species.
The slaughter method of brain stem severance by piercing through the eye socket or skull bone without prior stunning is not acceptable in any species.
nb: first adopted in 2005; most recent update adopted in 2016.
2018 ©OIE - Terrestrial Animal Health Code |
