Stunning is the process of rendering animals immobile or unconscious, with or without killing the animal, when or immediately prior to slaughtering them for food.

Rationale

Within the

European Union The European Union (EU) is a supranational union, supranational political union, political and economic union of Member state of the European Union, member states that are located primarily in Europe, Europe. The union has a total area of ...

, most animals slaughtered for human consumption are killed by cutting major

blood vessel The blood vessels are the components of the circulatory system that transport blood throughout the human body. These vessels transport blood cells, nutrients, and oxygen to the tissues of the body. They also take waste and carbon dioxide awa ...

s in the

neck The neck is the part of the body on many vertebrates that connects the head with the torso. The neck supports the weight of the head and protects the nerves that carry sensory and motor information from the brain down to the rest of the body. In ...

thorax The thorax or chest is a part of the anatomy of humans, mammals, and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main divisions of the c ...

so that rapid blood loss occurs. After a certain degree of blood loss has occurred, the animal will become unconscious, and after a greater blood loss

death Death is the irreversible cessation of all biological functions that sustain an organism. For organisms with a brain, death can also be defined as the irreversible cessation of functioning of the whole brain, including brainstem, and brain ...

will ensue. From the moment of cutting until the loss of consciousness, the animal experiences

pain Pain is a distressing feeling often caused by intense or damaging stimuli. The International Association for the Study of Pain defines pain as "an unpleasant sensory and emotional experience associated with, or resembling that associated with, ...

stress Stress may refer to: Science and medicine * Stress (biology), an organism's response to a stressor such as an environmental condition * Stress (linguistics), relative emphasis or prominence given to a syllable in a word, or to a word in a phrase ...

and

fear Fear is an intensely unpleasant emotion in response to perceiving or recognizing a danger or threat. Fear causes physiological changes that may produce behavioral reactions such as mounting an aggressive response or fleeing the threat. Fear ...

. Without stunning, the time between cutting through the major blood vessels and insensibility, as deduced from behavioural and

brain A brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as Visual perception, vision. I ...

response, is up to 20 seconds in

sheep Sheep or domestic sheep (''Ovis aries'') are domesticated, ruminant mammals typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus '' Ovis'', in everyday usage it almost always refers to domesticate ...

, up to 25 seconds in pigs, up to 2 minutes in

cattle Cattle (''Bos taurus'') are large, domesticated, cloven-hooved, herbivores. They are a prominent modern member of the subfamily Bovinae and the most widespread species of the genus '' Bos''. Adult females are referred to as cows and adult ...

, up to 2.5 or more minutes in

poultry Poultry () are domesticated birds kept by humans for their eggs, their meat or their feathers. These birds are most typically members of the superorder Galloanserae (fowl), especially the order Galliformes (which includes chickens, qu ...

, and sometimes 15 minutes or more in

fish Fish are Aquatic animal, aquatic, craniate, gill-bearing animals that lack Limb (anatomy), limbs with Digit (anatomy), digits. Included in this definition are the living hagfish, lampreys, and Chondrichthyes, cartilaginous and bony fish as we ...

. If one seeks to minimise animal suffering in slaughter, stunning is necessary. The best stunning method depends on the species; the quality of equipment and the adequate training of personnel also influence effectiveness.

History

A primitive form of stunning was used in premodern times in the case of

, which were poleaxed prior to being bled out. However, prior to slaughter pistols and electric stunners, pigs,

and other animals (including cattle) were simply struck while fully conscious. The belief that it was unnecessarily cruel to slaughter an animal against its will eventually led to the compulsory adoption of stunning methods in many countries. One of the first campaigners on the matter was the eminent physician,

Benjamin Ward Richardson Sir Benjamin Ward Richardson (31 October 1828 – 21 November 1896) was a British physician, anaesthetist, physiologist, sanitarian, and a prolific writer on medical history. He was the recipient of the Fothergill gold medal, awarded by the M ...

, who spent many years of his later working life developing more ‘humane’ methods of slaughter. As early as 1853, he designed a lethal chamber that would gas animals to death supposedly painlessly and without their knowledge, and he founded the Model Abattoir Society in 1882 to investigate and campaign for other methods of slaughter. He even experimented with the use of electric current at the Royal Polytechnic Institution. Cattle Market- Everyday Life at Cattle Markets in Kent, England, UK, 1944 D22206

Cattle Market- Everyday Life at Cattle Markets in Kent, England, UK, 1944 D22206

The development of stunning technologies occurred largely in the first half of the twentieth century. In 1911, the Council of Justice to Animals (later the Humane Slaughter Association) was created to improve the slaughter of livestock and address the killing of unwanted pets. In the early 1920s, the HSA introduced and demonstrated a mechanical stunner, which led to the adoption of stunning by many local authorities." The HSA played a key role in the passage of the Slaughter of Animals Act 1933. This made the mechanical stunning of cows and electrical stunning of pigs compulsory, with the exception of

Jewish Jews ( he, יְהוּדִים, , ) or Jewish people are an ethnoreligious group and nation originating from the Israelites Israelite origins and kingdom: "The first act in the long drama of Jewish history is the age of the Israelites""The ...

and Muslim meat. Modern methods, such as the

captive bolt pistol A captive bolt (also variously known as a cattle gun, stunbolt gun, bolt gun, or stunner) is a device used for stunning animals prior to slaughter. The goal of captive bolt stunning is to inflict a forceful strike on the forehead with the bo ...

and electric tongs were required and the Act's wording specifically outlawed the

poleaxe The poleaxe (also pollaxe, pole-axe, pole axe, poleax, polax) is a European polearm that was widely used by medieval infantry. Etymology Most etymological authorities consider the ''poll''- prefix historically unrelated to "pole", instead mea ...

. The period was marked by the development of various innovations in slaughterhouse technologies, not all of them particularly long-lasting.

Modern methods

In modern slaughterhouses a variety of stunning methods are used on livestock. Methods include: *Electrical stunning *Gas stunning *Percussive stunning

Electrical stunning

Electrical stunning is done by sending an electric current through the

and/or

heart The heart is a muscular Organ (biology), organ in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as ca ...

of the animal before slaughter. Current passing through the brain induces an immediate but non-fatal general

convulsion A convulsion is a medical condition where the body muscles contract and relax rapidly and repeatedly, resulting in uncontrolled shaking. Because epileptic seizures typically include convulsions, the term ''convulsion'' is sometimes used as a ...

that produces

unconsciousness Unconsciousness is a state in which a living individual exhibits a complete, or near-complete, inability to maintain an awareness of self and environment or to respond to any human or environmental stimulus. Unconsciousness may occur as the r ...

. Current passing through the heart produces an immediate

cardiac arrest Cardiac arrest is when the heart suddenly and unexpectedly stops beating. It is a medical emergency that, without immediate medical intervention, will result in sudden cardiac death within minutes. Cardiopulmonary resuscitation (CPR) and possi ...

that also leads shortly to unconsciousness and death. It is a controversial subject however. With chickens for example, over stunning leads to bone fractures and/or electrocution which prevents bleeding of the animal. This negatively affects the quality of the meat, and therefore under stunning is an attractive practice for slaughterhouses. In the

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, for example, the law states that poultry must be stunned for 4 seconds minimum with an average current of 100mA, which leads to systematic under stunning. The CrustaStun is a device designed to administer a lethal electric shock to

shellfish Shellfish is a colloquial and fisheries term for exoskeleton-bearing aquatic invertebrates used as food, including various species of molluscs, crustaceans, and echinoderms. Although most kinds of shellfish are harvested from saltwater environ ...

(such as

lobsters Lobsters are a family (Nephropidae, synonym Homaridae) of marine crustaceans. They have long bodies with muscular tails and live in crevices or burrows on the sea floor. Three of their five pairs of legs have claws, including the first pair, ...

crabs Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirely under the thorax. They live in all the ...

, and

crayfish Crayfish are freshwater crustaceans belonging to the clade Astacidea, which also contains lobsters. In some locations, they are also known as crawfish, craydids, crawdaddies, crawdads, freshwater lobsters, mountain lobsters, rock lobsters, m ...

) before cooking. This avoids boiling a live shellfish which may be able to experience

in a way similar to vertebrates. The device works by applying a 120

volt The volt (symbol: V) is the unit of electric potential, electric potential difference (voltage), and electromotive force in the International System of Units (SI). It is named after the Italian physicist Alessandro Volta (1745–1827). Defin ...

2–5 amp electrical shock to the animal. It is reported the CrustaStun renders the shellfish unconscious in 0.3 seconds and kills the animal in 5 to 10 seconds, compared to 3 minutes to kill a lobster by boiling or 4.5 minutes for a crab.

Gas stunning

With gas stunning animals are exposed to a mixture of breathing gases (

argon Argon is a chemical element with the symbol Ar and atomic number 18. It is in group 18 of the periodic table and is a noble gas. Argon is the third-most abundant gas in Earth's atmosphere, at 0.934% (9340 ppmv). It is more than twice a ...

and

nitrogen Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...

for example) that produce unconsciousness or death through hypoxia or

asphyxia Asphyxia or asphyxiation is a condition of deficient supply of oxygen to the body which arises from abnormal breathing. Asphyxia causes generalized hypoxia, which affects primarily the tissues and organs. There are many circumstances that can ...

. The process is not instantaneous and leads to respiratory stress when done with

carbon dioxide Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is t ...

Percussive stunning

With percussive stunning, a device which hits the animal on the head, with or without penetration, is employed. Such devices, such as the

, can be either pneumatic, or powder-actuated. Percussive stunning produces immediate unconsciousness through brain trauma.

Gallery

File:Schlachtschussapparat (modified).jpg, Captive bolt pistol File:TED Stunner Captive Bolt Technology.jpg, Modern captive bolt device File:Stunning with captive bolt gun.jpeg, Stunning a cow with a captive bolt File:Betäubung.jpeg, Directions for positioning bolt gun to ensure swift stunning

European regulations

The European Convention for the Protection of Animals for Slaughter, or Slaughter Convention (

Council of Europe The Council of Europe (CoE; french: Conseil de l'Europe, ) is an international organisation founded in the wake of World War II to uphold human rights, democracy and the rule of law in Europe. Founded in 1949, it has 46 member states, with a p ...

, 1979), requires all large animals to be stunned before slaughter through one of the three modern methods (concussion, electronarcosis, or gas), and prohibits the use of pole-axes, hammers and puntillas. Parties may permit exemptions for religious slaughter, emergency slaughter, slaughter of poultry, rabbits and other small animals. On the other hand, the

European Court of Justice The European Court of Justice (ECJ, french: Cour de Justice européenne), formally just the Court of Justice, is the supreme court of the European Union in matters of European Union law. As a part of the Court of Justice of the European U ...

(an EU institution) ruled on 17 December 2020 that member states of the European Union may also require a reversible pre-cut stunning procedure in ritual slaughter in order to promote animal welfare.

United States regulations

Stunning is regulated by the provisions of the Humane Methods of Slaughter Act (7 U.S.C. 1901), which the

Food Safety and Inspection Service The Food Safety and Inspection Service (FSIS), an agency of the United States Department of Agriculture (USDA), is the public health regulatory agency responsible for ensuring that United States' commercial supply of meat, poultry, and egg pro ...

(FSIS) is mandated to uphold under the

Federal Meat Inspection Act The Federal Meat Inspection Act of 1906 (FMIA) is an American law that makes it illegal to adulterate or misbrand meat and meat products being sold as food, and ensures that meat and meat products are slaughtered and processed under strictly r ...

(21 U.S.C. 603 (b)). No similar provision exists in the Poultry Products Inspection Act of 1957 (21 U.S.C. 451 et seq.). After confirmation of the first U.S. BSE case, FSIS issued regulations (69 FR 1887, 12 January 2004) prohibiting the use of the most widely used stunning device (air-injection captive bolt stun gun) because the compressed air device (in contrast to the blank cartridge-driven or non-penetrating captive bolt) has been shown to force pieces of brain and other central nervous system (CNS) tissue into the bloodstream. Cattle blood is processed primarily for use as a protein supplement in animal feeds and milk replacer for calves, and could transmit BSE if it contained specified risk materials (SRMs include brain and CNS tissue).CRS Report for Congress: Agriculture: A Glossary of Terms, Programs, and Laws, 2005 Edition - Order Code 97-905

References

External links

{{Wiktionary
The Food and Agricultural Organisation (FAO)
outlines practical suggestions for humane handling and slaughter of livestock. Meat industry Animal killing