> Factory Farming - Index >
Slaughter - Index
HAROLD HILLMAN Mb BSc PhD
animals and 650,000 tons of fish are slaughtered each year for food in
Britain. The number of fishes is not known because they are weighed, and
small fishes are thrown back dead into the sea, because it is illegal to
land them. Anglers catch an additional number of fish, and an unknown number
of birds and rabbits are shot.
Farm animals are stunned by electricity
or percussion, and killed by cutting the blood vessels in the neck, causing exsanguination. The halal and shechita method, used by Moslems and Jews,
involves cutting the neck without stunning the animals. Shooting may be
at close quarters, e.g. of horses, or from a distance, e.g. birds and rabbits.
Fish caught at sea or by anglers die of asphyxia, when they are taken out
of the water; anglers sometimes throw fish back after withdrawing the hooks;
the fish may then die of inability to eat, or microbial or fungal infections.
Trapping, snaring and hunting are rarely used in Britain for animals which
are to be eaten. Most animals in Britain are stunned.
Bailhere's Comprehensive Veterinary Dictionary (1988) defines it as "producing
unconsciousness of head in carbon dioxide, gas, electrical shock ... all
of them aiming to allow the animal to bleed out while it is still alive.
An animal that is dead before it has bled out will be unsuitable for marketing."
The latter definition regards stunning as rendering an animal unconscious,
and the exsanguination as the cause of death. However, the Oxford English
Dictionary (1989) says that the aim of stunning is "to deprive of
consciousness or power of motion [my italics] by a blow, a fall
or the like." The author of this entry gives paralysis as an alternative
to loss of consciousness.
The captive bolt may penetrate
the skull and destroy brain tissue, or cause a considerable rise in intracranial
pressure. These result in instantaneous loss of consciousness (as a knock-out
does in boxing), followed by collapse of the animal. If the brain tissue
is not destroyed, the animal may come round, if the carotid arteries and
jugular veins are not cut soon ("sticking"). Instant unconsciousness
occurs if the aim is accurate, the animal is still, and the device works.
Electrical stunning involves passing a large voltage across the animal's
brain. Slaughtermen, butchers, the Royal Society for the Prevention of
Cruelty to Animals, the People's Dispensary for Sick Animals, Compassion
in World Farming and most people who eat meat, assume that the electric
current causes instantaneous unconsciousness, so that the animals feel
no pain. Unfortunately, there is evidence that this assumption may not
Early in the 19th century, the
neurologists Sir Charles Bell in Britain and Francois Magendie in France
recognised the distinctions - both anatomical and physiological - between
the sensory and motor nervous systems. Electric stimulation of the skin
with low voltages and currents causes a tingling sensation, while higher
power causes pain and burns, due to action on the sensory nerve endings
in the skin. Stimulation of motor nerves or of muscle directly with low
voltages and currents, causes muscles to contract, while higher powers
causes spasm and paralysis. It is an everyday experience that, for example,
a patient whose finger is anaesthetized locally to lance a whitlow, can
still flex it. A spastic person can still feel. It is not permitted to
do experiments on paralyzed animals, because they can still feel. Every
physiologist, doctor and nurse, encounters examples showing the distinction
between the sensory and motor systems.
Can an Electrically Stunned Animal Feel Pain?
There is evidence from human beings
that electrical stimulation is painful. Electrical current is widely used
to torture people in South America/ the Middle East and China; cattle prods
or electric batons are used. Victims of torture attest that the larger
the voltage or current, the more painful it is; they do not go unconscious
immediately. The power used to torture people is of the same order as that
used to stun animals. Greater energy used in the electric chair kills the
victim after some minutes, or spoils the taste of meat. Of course, the
voltages and currents experienced by the human beings or animals are much
lower than those coming out of the devices they use, because the electrodes
can not be applied accurately and firmly, and there are alternative pathways
across the skin, through the skin and into the tissues. In the case of
prisoners in the electric chair, the electrodes are moistened and bound
firmly to the head and foot to ensure good contact.
Burns occur at the sites of contact with the electrodes. Those due to torture of human beings may be
very small. They have been detected histologically in biopsies taken from
victims at the Rehabilitation and Research Centre for Torture Victims in
Copenhagen. Massive burns and charring are seen at the sites where the
electrodes are attached when the electric chair is used. Patients who are
given electroshock for manic depression, are anaesthetised because of the
stress and pain which would be caused. Other patients, whose hearts require
defibrillation with large amounts of energy, are now anaesthetized, because
those who recovered complained of the pain. Powerful muscle contraction
causes painful cramps in athletes. Perhaps the most obvious evidence is
that it is painful to touch the electric mains. Why, then, is it so widely
believed that electrical stunning is humane?
Why Electrical Stunning is not Believed to be Painful
Firstly, the public, the slaughterers,
the farmers and the butchers, have not understood the division of the nervous
system into sensory and motor systems. Secondly, animals and people subjected
to large currents, being paralysed, can not exhibit the obvious sign of
pain - evasive and violent movements. Thirdly, people believe that unconsciousness
in animal slaughter (as in the electric chair) is instantaneous. Fourth,
N Gregory and S Wotton of the Department of Meat Animal Science of the
University of Bristol in 1985 applied the electric current to the heads
of sheep for too short a period to stun or kill them; when the current
was turned off, the sheep walked away, apparently without distress. They
also saw no burns beneath the electrodes. Nevertheless the same research
group was of the opinion that "electrical stunning does not cause de-afferentation of the visual cortex in a consistent and prolonged manner."
Fifthly, no one wants to know that animals might have suffered severe pain
every time they eat a ham sandwich, hold a barbecue or put on their sheepskin
Large numbers of animals are slaughtered
rapidly in an assembly line. Chickens are lifted by their legs when they
are fully conscious. Their heads are immersed in water to make electrical
contact, but some flutter and are not stunned. Chickens and pigs are subjected
to scalding water to remove their feathers and hair. When stunning is not
done properly or exsanguination has not progressed enough, a significant
proportion of animals is burnt before going unconscious.
Halal and shechita are both widely
used in Britain. The animals are not stunned either by percussion or electrical
current. Their necks are exposed, and their carotid arteries and jugular
veins cut rapidly with a sharp knife; they die by exsanguination. The restraint
and sudden exposure of their necks must be stressful, and the neck incision
must be painful. Those who practice this method justify it on the grounds
that: (a) their religions and holy books have sanctioned it for centuries;
(b) cutting with a sharp knife is not painful; (c) the animal becomes unconscious
immediately; (d) other methods are also cruel; (e) animals do not suffer
pain, or it does not matter.
Slaughter of Fish
The slaughter of fish has received
remarkably little attention. Fish die by asphyxia when they are taken out
of the water, or when they are ground up in vacuum fishing. If they have
been caught in nets, they may be exhausted from the attempts to free themselves.
Some customers in Britain prefer the fishes to be sold with their heads
still attached. Sometimes fish are gutted while their hearts are still
beating, and the beating is prolonged when they are put into ice. There
is no reason to believe that fish do not feel pain, and suffer stress in
the nets and during their agonal asphyxia.
Few people who eat meat or fish,
or products made from them are aware how the animals are killed. Penetrating
captive bolts kill the animals most quickly, and percussion is also effective,
if they are stuck before they come round. Electric stunning is probably
very painful, because the animals are fully conscious when they are electrocuted.
It would be impractical to anaesthetize the animals before exsanguinating
them, and the procedure of slaughter with carbon dioxide is too slow, although
the animals die quite quickly. The challenge to the meat and fish industry
is to devise methods of killing animals and fish in more humane ways, but
this may not be possible on an industrial scale. It is likely that kinder
and less stressful methods would make meat and fish more expensive.
Dr Harold Hillman is the Director
of the Unity Laboratory of Applied Neurobiology
in Guildford, and was formerly
Reader in Physiology at the University of Surrey.
He can be contacted at
76 Epsom Road, Guildford, Surrey, GU1 2BX, UK
Tel: [+44] 01483 568332
Fax: [+44] 01483 531110