• SANITATION FACILITIES
• ENVIRONMENT HYGIENE
• INSPECTION BEFORE SLAUGHTERING
• STUNNING TECHNIQUES
• RIGOR MORTIS
• INTERNATIONAL VARIATIONS
• MAJOR SLAUGHTERHOUSES
• IN VITRO
• SLAUGHTERHOUSE WASTE MANAGEMENT
• A slaughterhouse or abattoir is a facility where animals
are killed for consumption as food products.
Approximately 45-50% of the animal can be turned into
edible products (meat).
• About 15% is waste, and the remaining 40-45% of the
animal is turned into by-products such as leather, soaps,
candles (tallow), and adhesives.
• In the United States, around nine billion animals are
slaughtered every year(this includes about 150.4 million
cattle, bison, sheep, hogs, and goats and 8.9 billion
chickens, turkeys, and ducks) in 5,700 slaughterhouses
and processing plants employing 527,000 workers;
4. Contd …
• in 2009, 26.9 billion pounds of beef were consumed in
the U.S. alone. In Canada, 650 million animals are killed
annually. In the European Union, the annual figure is
300 million cattle,sheep, and pigs, and four
• Slaughterhouses which process meat unfit for human
consumption are sometimes referred to as Knacker's
yards or Knackeries.
• Slaughtering animals on a large scale poses significant
logistical problems and public health concerns, with
public aversion to meat packing in many cultures
influencing the location of slaughterhouses.
• In addition, some religions stipulate certain conditions
for the slaughter of animals so that practices within
• There has been criticism of the methods of
preparation, herding, and killing within some
slaughterhouses, and in particular of the speed with
which the slaughter is sometimes conducted.
• Investigations by animal welfare and animal
rights groups have indicated that a proportion of these
animals are being skinned or gutted while apparently
still alive and conscious.
• Many of these supposed cases are misinterpretations
of post-mortem death twitching as shown by
• There has also been criticism of the methods of
transport of the animals, who are driven for
hundreds of miles to slaughterhouses in conditions
that often result in crush injuries and death en
route. Slaughtering animals is opposed by animal
rights groups on ethical grounds.
• Slaughterhouses act as the starting point of the meat
industry, where stock come from farms/market to
enter the food chain. They have existed as long as
there have been settlements too large for individuals
to rear their own stock for personal consumption.
• Early maps of London show numerous stockyards in
the periphery of the city, where slaughter occurred in
the open air. A term for such open-air
slaughterhouse is a shambles. There are streets
named "The Shambles" in some English towns
(e.g. Worcester, York) which got their name from
having been the site on which butchers killed and
prepared animals for consumption .
• In the latter part of the 20th century, the layout and
design of most US slaughterhouses has been
significantly influenced by the work of Dr. Temple
Grandin. It was her fascination with patterns and
flow that first led her to redesign the layout of cattle
• While Grandin's primary objective is to help
slaughterhouse operators improve efficiency and
profit, she suggested that reducing the stress and
suffering of animals being led to slaughter may help
achieve this aim.
• In particular she applied an intuitive understanding
of animal psychology to design pens and
corrals which funnel a herd of animals arriving at a
slaughterhouse into a single file ready for slaughter.
• Her corrals employ long sweeping curves so that
each animal is prevented from seeing what lies
ahead and just concentrates on the hind quarters of
the animal in front of it. This design also attempts to
override the animals' survival instincts and prevent
them from reversing direction.
• Grandin now claims to have designed over 54% of
the slaughterhouses in the United States as well as
many other slaughterhouses around the world.
13. Curved cattle corrals designed by Temple Grandin are
intended to reduce stress in animals being led to
• It is impossible to give an adequate definition of
process hygiene because the critical points will
vary, depending on:
• processing buildings (site, size, buildings)
• equipment available
• permanent or non-permanent personnel
(working routines, training)
• climatic conditions
• sanitary facilities
• water and energy supplies
• liquid and solid waste disposal
• Site of buildings for slaughtering and processing
• The slaughterhouse should be situated away from
residential areas. Access for animals - either by
road, rail and/or stock route - must be assured.
The slaughterhouse should be located in areas
where flooding is impossible.
• An abundant supply of potable water as well as
adequate facilities for treatment and disposal is
• The land acquired for the proposed
slaughterhouse should be sufficient to permit
future expansion as overcrowding of facilities
may give sanitation problems.
• Where the “slaughterhouse” is more or less an open
slaughter place, trees may provide some shade or
even be used as a part of the structure. If the
slaughterhouse consists of regular buildings the
ground should be free of shrubbery or vegetation in
close proximity to the structure.
17. Sanitation facilities
• Water points, hoses, sterilizers for hand tools etc. and
cleaning equipment must be provided in sufficient
numbers. Where possible sterilizers should be supplied
with hot water instead of chemical disinfectants.
• Sanitary facilities must also include a sufficient number
of toilets/latrines and arrangements for hand-washing or
even possibilities for bathing (showering). These facilities
must be kept clean and well maintained.
• To avoid back-flow from toilets in case of flooding the
toilet outlets must be separated from common waste
• Areas/rooms for resting and eating may be required
assuring that food for the personnel and the
carcasses/meat cannot be mixed.
18. Environment hygiene
• Environmental hygiene and its implementation
will depend on the area where the
slaughterhouse/meat plant is situated. The
precautions to be taken will be different if the site
is in a town or in the country.
• The main principles of environmental hygiene will
• proper fencing (public, dogs, etc.)
• pest control (rodents, insects)
• liquid and solid waste disposal
• Proper fencing: To prevent access of unauthorized
persons, the public, dogs and other animals fencing
must be erected around the slaughterhouse area.
• Pest control:Pests (insect, rodents and birds) should
be controlled to prevent their access to
slaughterhouses, production areas and storage
departments. This is best achieved by the
construction of buildings and working places where
access of insects, rodents and birds is hindered, but
it will be almost impossible to secure buildings totally
• Insect control :Principles in insect control may
Biological control through emphasis on the
natural enemies of pests.
Cultural control through alteration of the
environment to make it unfavourable to pests.
Sanitation programmes and water
management are examples.
Physical and mechanical control. Burning and
sticky adhesives are examples.
21. Inspection before slaughtering
• Ante Mortem or before slaughter Establishments are
required to notify FSIS(food safety and inspection
service) inspection program personnel when they want
animals inspected prior to slaughter.
• Inspection at a slaughter establishment begins in the
ante mortem area or pen where FSIS inspection
program personnel inspect live animals before moving
• It is the establishment's responsibility to follow the
Humane Methods of Slaughter Act. Egregious
violations to humane handling requirements can lead
to suspension of inspection activity within an
establishment. This will stop the plant from operating.
• During this inspection, FSIS inspection program
personnel observe all animals at rest and in motion.
• Inspection program personnel are trained to look for
abnormalities and signs that could indicate disease
or health conditions that would prohibit the animal
from entering the food supply.
• If an animal goes down or shows signs of illness after
receiving and passing ante mortem inspection before
slaughter, the establishment must immediately notify
the FSIS veterinarian to make a case-by-case
disposition of the animal's condition. Alternatively,
the establishment may humanely euthanize the
23. • The following are stunning techniques used in
The Captive Bolt Pistol
Electric head-only stunning
Stun to kill techniques
CO2 Gas Stunning
Cardiac arrest stunning
24. The Captive Bolt Pistol
• This stunning method is widely used for all farmed
animals. There are two types of captive bolt pistol:
penetrative and non-penetrative.
• Penetrative: Penetrative stunners drive a bolt into
the skull and cause unconsciousness both through
physical brain damage and the concussive blow to
• non-penetrative: The bolt on a non-penetrative
stunner is 'mushroom-headed' and impacts on the
brain without entering the skull. Unconsciousness is
caused by the concussive blow.
• The bolt is described as 'captive' because it flies
out of the barrel but remains attached to the
pistol. The pistol is placed on the centre of the
animal's forehead and is either trigger-fired or
fires automatically on contact with the animal's
• Percentage of plants using the captive bolt pistols
(penetrative and mushroom-headed) according
to species and type of plant
Cattle (captive bolt/pith): 71.1%
Cattle (captive bolt only): 24.9%
• Pithing is carried out in the majority of cattle
slaughterhouses. The practice involves inserting a
wire or rod through the hole in the head made by
the captive bolt. The rod is slid up and down to
destroy the lower part of the brain and the spinal
• The Farm Animal Welfare Council say, 'From purely
hygiene considerations, the practice is not favoured.
Pithing is due to be banned in the UK during 2001.
Studies show that this process may risk BSE (Bovine
Spongiform Encephalopathy, or Mad Cow Disease)
infected brain material entering the animal's
29. Electric head-only stunning
• Electric head-only stunning with tongs is used to stun
cattle, calves, sheep, goats, pigs, rabbits and
ostriches. The operator places a pair of electric tongs
on either side of the animal's head and passes an
electric current through the brain - supposedly
causing a temporary loss of consciousness
• Percentage of plants using electric head-only
stunning according to species and type of plant as
• Cattle: 0.5%
• Sheep & goats: 56%
• Pigs: 73.9%
• The RSPCA (The Royal Society for the Prevention of
Cruelty to Animals) say that, 'There is increasing
scientific evidence that some animals stunned
electrically using tongs regain consciousness before
they die from loss of blood.'
• There are two reasons for this: either insufficient
electrical current passes through the brain to stun
the animal, or the time interval between stunning
and sticking exceeds 20 seconds and the animal
starts to regain consciousness.
• The Scientific Veterinary Committee of the EU says
that, 'Under the commercial conditions, a
considerable proportion of animals are either
inadequately stunned or require a second stun. This
is mainly because of poor electrode placements, bad
electrical contacts and long stun-to-stick intervals.'
• The Committee also expresses concern that, 'The
strength of electric current used should be high
enough for the species to induce a stun within one
second of application. Otherwise, the animals could
suffer a potentially painful electric shock before
• The Welfare of Animals at Slaughter Regulations 1995
state that electrodes should not be used to stun
animals unless the stunning apparatus incorporates a
device which, 'measures the impedance of a load and
prevents operation of the apparatus unless a current
can be passed which is sufficient to render an animal of
the species being stunned unconscious until it is dead.'
• In other words, electrical stunning equipment should
not be used unless a device is attached which disables
the equipment if a strong enough current cannot be
achieved. This law is being openly flouted because
according to the Meat Hygiene Service, 'such a device
is not currently commercially available.'
34. Waterbath stunning
• The electric water bath is widely used to stun chickens,
turkeys, ducks and geese. Birds are shackled upside
down on a moving conveyor which carries them to an
electrified water bath into which their heads are
supposed to be immersed.
• The shackles contact a bar which is connected to earth.
The strength of the electrical current has risen in
recent years - with the aim of ensuring that birds suffer
a cardiac arrest and die when they enter the water
• The Meat Hygiene Service report that in 1997/8 the
average electric current applied to chickens stunned in
an electric water bath was 157 mA.
35. Stun to kill techniques
• Traditionally, animals are stunned before their
throats are cut but the stun does not actually kill the
animal. Animals die from loss of blood after their
throats are cut.
• Stunning techniques do not kill animals outright
because it has always been assumed that the heart
needs to continue functioning so that as much blood
as possible can be pumped out of the animal before
s/he is eaten.
• However in their 1984, 'Report on the Welfare of
Livestock (Red Meat Animals) at the Time of
Slaughter', the Farm Animal Welfare Council point to
scientific research undertaken on pigs at the Meat
Research Institute which shows that if animals die
from a heart attack before they are knifed and bled
out there is 'no effect on the amount of blood lost,
the rate of loss or the residual content of blood in
• FAWC(farm animal welfare council) conclude that,
• 'the release of blood from the animal need not
necessarily occur prior to death... and should a
change of attitude come about variations could
advantageously be made in the design and operation
of stunning techniques.‘
• The following table shows that the number of
abattoirs using stunning methods which kill the
animal outright are very low
Sheep and goats - 3.5%
Pigs - 1.9% (not including CO2 gas stun/kill)
Chickens - 1.1% (gas stunning)
Cattle - 0.5%
38. CO2 Gas Stunning
• Four high throughput slaughterhouses stun and then
kill pigs by exposing them to a mixture of carbon
dioxide and air.
• The Meat Hygiene Service say that, 'The killing of pigs
by exposure to CO2 is used in only four
slaughterhouses but these premises process 25% of
the total number of pigs slaughtered each year.'
• 16.3 million pigs were killed in the UK in 1998, so
over 4 million were stunned using CO2 gas.
39. Cardiac arrest stunning
• Cattle, sheep, pigs, rabbits and goats can be stunned
and simultaneously given a cardiac arrest. However,
as the table above shows, very few abattoirs actually
use these methods.
• An electric current is either sent through the head
and body at the same time to span the brain and
heart or is sent though the head first to cause
unconsciousness and then across the chest to cause
a cardiac arrest.
• If administered correctly, these methods do at least
remove the risk of animals regaining consciousness
while they are bleeding to death as the heart attack
should kill the animal outright.
• However, the Scientific Veterinary Committee of the
EU say that when the second method is used, 'a
considerable proportion of animals are either
inadequately stunned or require a second stun.
• This is mainly because of poor electrode placements
and bad electrical contacts. Measures shall be taken
to avoid these practices. Otherwise, when using
method 2, the animals could suffer a potentially
painful cardiac arrest.'
• Sticking is the term used to describe sticking a knife
into an animal's throat or chest with the aim of
causing blood loss and brain death.
• When the neck is severed, the killing is described as
a 'neck stick' and when the major vessels near the
heart are severed, the killing is described as a
• After being stuck, an animal's blood pressure is
supposed to fall quickly, resulting in a rapid loss of
blood supply to the brain. If the major blood vessels
are adequately cut, animals should lose between 40
and 60% of their total blood volume.
• Researcher Steve Wotton explains that, 'Poor
sticking, leading to inadequate or delayed
exsanguination, can allow blood pressure to be
maintained so that sensibility is regained before
• In order to ensure that animals are not recovering
from a stun, slaughter men are supposed to check
that animals have an absence of rhythmic breathing
movements and an absence of a corneal (eye) reflex.
43. OVER ALL PROCESS
• The slaughterhouse process differs by species and region and
may be controlled by civil law as well as religious laws such
as Kosher and Halal laws. A typical procedure follows:
1.Cattle (mostly steers and heifers, some cows, and even fewer
bulls) are received by truck or rail from a ranch, farm,
2.Cattle are herded into holding pens.
3. Cattle are rendered unconscious by applying an electric
shock of 300 volts and 2 amps to the back of the head,
effectively stunning the animal, or by use of a captive bolt
pistol to the front of the cow's head (a pneumatic or
cartridge-fired captive bolt). Swine can be rendered
unconscious by CO2/inert gas stunning. (This step is prohibited
under strict application of Halal and Kashrut codes.)
4.Animals are hung upside down by both of their hind
legs on the processing line.
5.The carotid artery and jugular vein are severed with
a knife, blood drains, causing death
6.The head is removed, as well as front and rear feet.
Prior to hide removal, care is taken to cut around
the digestive tract to prevent fecal contamination
later in the process.
7.The hide/skin is removed by down pullers, side
pullers and fisting off the pelt (sheep and goats).
Hides can also be removed by laying the carcase on a
cradle and skinning with a knife.
8.The internal organs are removed and inspected for
internal parasites and signs of disease. The viscera are
separated for inspection from the heart and lungs,
referred to as the "pluck." Livers are separated for
inspection, tongues are dropped or removed from the
head, and the head is sent down the line on the head
hooks or head racks for inspection of the lymph nodes
for signs of systemic disease.
9.The carcase is inspected by a government inspector for
safety. (This inspection is performed by the Food Safety
Inspection Service in the U.S., and Canadian Food
Inspection Agency in Canada.)
10.Carcases are subjected to intervention to reduce levels
of bacteria. Common interventions are steam, hot water,
and organic acids.
11.Carcases (typically cattle and sheep only) can
be electrically stimulated to improve meat
12.Carcases are chilled to prevent the growth
of microorganisms and to reduce meat deterioration
while the meat awaits distribution.
13.The chilled carcase is broken down into primal
cuts and subprimals for boxed meat unless customer
specifies for intact sides of meat. Beef and horse
carcases are always split in half and then quartered,
pork is split into sides only and goat/veal/mutton
and lamb is left whole
14.The remaining carcase may be further processed to
extract any residual traces of meat, usually
termed advanced meat recovery or mechanically
separated meat, which may be used for human or
15.Waste materials such as bone, lard or tallow, are
sent to a rendering plant. Also, lard and tallow can be
used for the production of biodiesel or heating oil.
16.The wastewater, consisting of blood and fecal
matter, generated by the slaughtering process is sent
to a waste water treatment plant.
17.The meat is transported to distribution centers that
then distribute to retail markets.
48. Rigor mortis
• Rigor mortis (Latin meaning "stiffness of
death") is one of the recognizable signs
of death that is caused by a chemical change
in the muscles after death, causing the limbs
of the corpse to become stiff and difficult to
move or manipulate. In humans it commences
after about 3 hours, reaches maximum
stiffness after 12 hours, and gradually
dissipates until approximately 72 hours (3
days) after death. Heat sources such as fire or
exercise can speed up the process of rigor
• Rigor mortis is very important in meat technology.
The onset of rigor mortis and its resolution partially
determines the tenderness of meat. If the post-
slaughter meat is immediately chilled to 15°C (59°F),
a phenomenon known as cold shortening occurs,
where the muscle shrinks to a third of its original
size. This will lead to the loss of water from the meat
along with many of the vitamins, minerals, and water
soluble proteins. The loss of water makes the meat
hard and interferes with the manufacturing of
several meat products like cutlet and sausage.
• Cold shortening is caused by the release of
stored calcium ions from the sarcoplasmic
reticulum of muscle fibres in response to the cold
stimulus. The calcium ions trigger powerful
muscle contraction aided by ATP molecules. To
prevent cold shortening, a process known as
electrical stimulation is carried out, especially in
beef carcasses, immediately
after slaughter and skinning. In this process,
the carcass is stimulated with alternating current,
causing it to contract and relax, which depletes
the ATP reserve from the carcass and prevents
51. International variations
• The standards and regulations governing
slaughterhouses vary considerably around the world.
In many countries the slaughter of animals is
regulated by custom and tradition rather than by law.
In the non-Western world, including the Arab world,
the Indian sub-continent, etc., both forms of meat
are available: one which is produced in
modern mechanized slaughterhouses, and the other
from local butcher shops.
• In some communities animal slaughter may be
controlled by religious laws,
notably halal for Muslims and kashrut for Jewish com
• These both require that the animals being
slaughtered should be conscious at the point of
death, and as such animals cannot be stunned prior
• This can cause conflicts with national regulations
when a slaughterhouse adhering to the rules of
kosher preparation is located in some Western
• In Islamic and Jewish law, captive bolts and other
methods of pre-slaughter paralysis are generally
not permissible, due to it being forbidden for an
animal to be killed prior to slaughter.
• Various halal food authorities have more recently
permitted the use of a recently developed fail-
safe system of head-only stunning where the
shock is less painful and non-fatal, and where it is
possible to reverse the procedure and revive the
animal after the shock.
• In many societies, traditional cultural and religious
aversion to slaughter led to prejudice against the
people involved. In Japan, where the ban on
slaughter of livestock for food was lifted only in the
late 19th century, the newly found slaughter industry
drew workers primarily from villages of burakumin,
who traditionally worked in occupations relating to
• Some countries have laws that exclude specific
animal species or grades of animal from being
slaughtered for human consumption, especially
those that are taboo food.
• The former Indian Prime Minister Atal Behari
Vajpayee suggested in 2004 introducing legislation
banning the slaughter of cows throughout India,
as Hinduism holds cows as sacred and considers their
slaughter unthinkable and offensive. This was often
opposed on grounds of religious freedom. The
slaughter of cows and the importation of beef into the
nation of Nepal are strictly forbidden. Several U.S.
states have banned the slaughter and consumption of
dogs. The sale and consumption of horse meat is illegal
in The United States, although horses are
slaughtered for meat export to Europe and Japan for
human consumption and for the U.S. pet food market.
• Most countries have laws in regard to the treatment
of animals at slaughterhouses. In the United States,
there is the Humane Slaughter Act of 1958, a law
requiring that all swine, sheep, cattle, and horses be
stunned unconscious with just one application of a
stunning device by a trained person before being
shackled and hoisted up on the line (chickens are
exempt from this Act).
• The United States Department of Agriculture (USDA)
is opposed to the Humane Slaughter Act, and
violations of the Act carry no penalties.
• Since stopping the line to re-knock conscious animals
causes "down time" and results in lower profits, the
Humane Slaughter Act is usually bypassed and
ignored by USDA supervisors
• There is some debate over the enforcement of this
act. This act, like those in many countries, exempts
slaughter in accordance to religious law, such
as kosher shechita and dhabiĥa halal. Most strict
interpretations of kashrut require that the animal be
fully sensible when its carotid artery is cut.
• The novel The Jungle detailed unsanitary conditions
in slaughterhouses and the meatpacking industry
during the 1800s. This led directly to an investigation
commissioned directly by the President, and to the
passage of the Meat Inspection Act and the Pure
Food and Drug Act of 1906, which established
the Food and Drug Administration. A much larger
body of regulation deals with the public health and
worker safety regulation and inspection.
• Historically, some doubted that fish could experience
pain. However, laboratory experiments have shown
that fish do react to painful stimuli (e.g. injections of
bee venom) in a similar way to mammals.
• The expansion of fish farming as well as animal
welfare concerns in society has led to research into
more humane and faster ways of killing fish.
• In large-scale operations like fish farms, stunning fish
with electricity or putting them into water saturated
with nitrogen so that they cannot breathe, results in
death more rapidly than just taking them out of the
• For sport fishing, it is recommended that fish
be killed soon after catching them by hitting
them on the head followed by bleeding out, or
by stabbing the brain with a sharp
object (called pithing or ike jime in Japanese).
62. Major slaughterhouses
• The largest slaughterhouse in the world is operated
by the Smithfield Packing Company in Tar Heel, North
Carolina. It is capable of butchering over 32,000 pigs
a day. In the US, the majority of major meat packing
plants are located in the Midwestern and High Plains
63. In vitro meat
• "In-Vitro meat is the manufacturing of meat products
through 'tissue-engineering' technology. Cultured
meat ( in-vitro meat) could have financial, health,
environmental, and animal welfare advantages over
traditional meat. The idea: To produce animal meat,
simply without using an animal. Starting cells are
taken painlessly from live animals, they are put into a
culture media where they start to proliferate and
grow, independently from the animal."
• A 2009 article in h+ magazine (published by
Humanity+) predicts that as a result of the
introduction of in vitro meat, the
slaughterhouse will eventually become an
unneeded institution when animal meat is
created from the DNA of the animal instead of
its dead carcase. Only sentimental values will
keep the butcher stores and slaughter houses
open as people switch to in vitro meat.
• We still do not understand Stunning; what it
does exactly and how it stuns the animal (even in
ECT (Electroconvulsive therapy) for the human,
we also do not know what it does and how it
works). We are still unable to define pain and
sensation of the animal (and we will be unlikely
to do so) and to understand the loss of
consciousness and its relation to pain.
• Many scientists opposed to the use of stunning
• With regard to Pain. I would like to quote
from the FAWC(farm animal welfare council)
Report (1985), ‘There is a lack of scientific
evidence to indicate at what stage in the
process of losing consciousness the ability to
feel pain ceases.’
• Grandin, T. "Best Practices for Animal Handling and
Stunning", Meat & Poultry, April 2000, pg. 76.
• Williams, Erin E. and DeMello, Margo. Why Animals
Matter. Prometheus Books, 2007, p. 49.