Applying the Anoxia Method for culling small poultry flocks on organic farms

DESCRIPTION ANOXIA METHOD FOR EUTHANISING ANIMALS © AVT AB 2015
THE ANOXIA METHOD
APPLYING THE ANOXIA METHOD FOR EUTHANIZING POULTRY
Detailed description of the general principles of the Anoxia method
How the Anoxia method can be used for euthanizing animals in the context of
managing a small-scale outbreak
Euthanizing 6.000 floor-bred chickens
Within a time frame of 6 hours - using 5 experienced poultry workers
Under the supervision of 1 veterinarian and one veterinary extension worker
Harm Kiezebrink
Thursday, 12 March 2015
Anoxia Foam Technology has been developed by Harm Kiezebrink, AVT Applied Veterinary Technologies N2GF Project
leader: Harm Kiezebrink: +46-761 731 779 or +44 7452 272358, mail: harm.kie@gmail.com
The Anoxia Method is commercially available as N2GF® through Anoxia Europe BV
Hoge Eng Oost 52A, 3882 TN Putten, The Netherlands: +31-34170687 Mail: info@anoxia-europe.com
Web sites: http://www.n2gf.com and http://www.anoxia-europe.com
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THE ANOXIA METHOD
APPLYING THE ANOXIA METHOD FOR EUTHANIZING POULTRY - SUMARY
Humane killing of animals
The Anoxia method is the most humane method to euthanize animals that are in severe
pain or suffer severely seems to be the use of nitrogen gas foam. By this method the
animals will be unconscious within a short time through an abundance of nitrogen. The
animals die in a short time, without regaining consciousness.
The method of nitrogen gas foam uses a barrel, filled up with a layer of high expansion foam
(big bubbles) completely filled with pure nitrogen. The animal will be placed in the foam and
covered with a layer of foam of at least 60 centimetres. The animal will breathe 98 per cent
nitrogen. The amount of oxygen in the blood diminishes very quickly and the animal will
very soon be unconscious. Because of the extreme oxygen deficiency (anoxia) the animal
dies within one and a half to two minutes. The animal will not regain consciousness and
won’t notice that it dies.
The animal will be unaware that it breathes in pure nitrogen and it will not be harmful or
painful for the animal because the normal air an animal breathes consists already of 78 per
cent nitrogen. Inhalation of nitrogen is therefore not stressful, whereas for example with
high concentrations of carbon dioxide the animal will try not to breathe.
The Anoxia method is not physically demanding on the farmer and his employees. The
animals almost instantly lose consciousness after being dipped through the foam. Fixation
of the animal to avoid them to hurt themselves during stunning is not needed, as necessary
in most other methods. Because of the thick nitrogen foam layer and the amount of 98 per
cent nitrogen it is certain that the animal will die. The chance that the method fails and the
animal regain consciousness and won’t die, is next to zero.
Description of the disposable container
Disposable containers consist of two bags, one inside the other. The disposable container is
made from tear-resistant material. Both can be burnt safely. A set consists of one
disposable container and five liners.
A disposable container is lined with a liner and filled with high expansion foam filled with
>98% nitrogen by volume (Anoxia foam). The logistics of the nitrogen gas bottles involved
are the same as those for the corresponding CO2 container gassing system. Depending on
container size, the birds are placed into the foam-filled containers inside or outside the
house. It is also possible to foam the birds directly in the Disposable containers without
using a container. After filling and foaming, the Disposable containers are sealed so they are
airtight.
Advantages
The advantages of the Anoxia method using disposable containers are:
• Simplicity - simple instructions – simple Standard Operating Procedure - widely
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available bottled nitrogen or oxygen/nitrogen generator – disposable containers
are easy to assemble – easy to operate – easy to clean & disinfect
• Easy to operate: simple instructions – simple Standard Operating Procedure
• Cost effective – if only a small number of animals need to be euthanized, bottled
nitrogen can be used. Bottled nitrogen is one of the most affordable bottled gases,
globally available at any gas filling station
• Safety - Nitrogen is non-toxic inert gas; atmospheric air consist 78% nitrogen–
safe storage/transport – safe disposal - no reuse of the disposable containers
• Multiple usage: single sick or cripple animals – backyard situations and small
number of animals (<100 birds) – all housing systems with up to 38.000 animals
• Animal welfare friendly: birds are stunned and euthanized by anoxia without any
additional stress or pain
• All-in-one culling bag system: fully disposable – euthanize – carcass
storage/transport – carcass disposal
• Reduced risks of spreading: disposable containers can be used inside different
types of poultry housing systems
• Easy handling: light weight - easy to assemble - easy to transport - easy to store
• Safe process: Nitrogen is non-toxic – safe storage/transport – safe disposal
• Low operating costs, no investments: disposable materials - low logistic costs -
simple cleaning and disinfection - easy storage - no maintenance costs - no
advanced investments for complicated mobile slaughter equipment - no need for
long-term storage facilities - no need for special transportation of heavy
equipment
• Separated processes: The carcasses of the slaughtered animals are stored safely
in a thick plastic bag, transportable on a plywood pallet.
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PROTOCOL CONTENT
Part 1: General principles of the Anoxia method
Part 2: Detailed description of the method for euthanizing animals in the context of
managing a small scale outbreak, euthanizing a stock of 6.000 floor-bred
chickens within a time frame of 6 hours, using 5 experienced poultry workers,
under the supervision of 1 veterinarian and one veterinary extension worker.
Part 3: Technical materials list.
Part 4:Brief description of a back-up system using CO2.
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PART 1: GENERAL PRINCIPLES OF THE ANOXIA METHOD
• Background information
Most of the mobile poultry slaughter equipment and -techniques used within Europe have
been developed under the pressure during on-going large-scale outbreaks in the
Netherlands and Belgium in 2003. Though somewhat modified and there have been minor
improvements since then, all existing equipment and techniques still are limited in their
practical use under different housing conditions or with different species. These techniques
do not allow for to a humane treatment of animals nor do these techniques prevent the
virus to infect humans when applying these techniques.
• EU 1099/2009
Based on lessons learnt of these experiences on January 1, 2013, EU Regulation EU
1099/2009 was issued. This rule applies to the slaughter and killing of animals, including the
euthanizing of farm animals. In this new regulation, killing and euthanizing animals on the
farm has been strictly regulated to prevent unnecessary stress or pain. Therefore, since
2004, the Anoxia method was developed as a technical solution to improve animal welfare,
simplify procedures, prevent Human to Animal contact, increase efficiency & effectiveness
and to reduce operational costs. The Anoxia method is fully compliant to the new EU
Regulation.
• Proof of Principle
Specially designed to perform euthanasia on animals the method is based on the principle
that mammals cannot survive without oxygen. The Anoxia method is absolutely unique in
its kind. Animals become unconscious without being aware of it because atmospheric
oxygen is replaced by >98% nitrogen in a controlled environment created by the foam.
Therefore, the animals suffer a minimum of pain and distress. In the 2013 May issue of
Poultry Science 1, proof-of-principle for the Anoxia method has been presented. It states
that submersion in nitrogen foam provides is a rapid and highly effective method of
euthanasia causing loss of consciousness of poultry within 15-20 seconds.
1 2013 Poultry Science 92:1145-1154
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• Euthanizing animals on the farm
There are various reasons why animals need to be euthanized on the farm or at the hatchery:
they have been selected based on gender, they are incurable (and especially painful) sick or
crippled, during outbreaks of diseases, in case of lack of resources to continue supporting
the animal, or animals that have been used for laboratory test procedures that need to be
disposed of.
The Anoxia method is an Animal Euthanasia method in accordance with EU 1099/2009 and
therefore permitted under this new regulation. Euthanasia differs from animal slaughter
and pest control, which are performed for purposes other than an act of mercy, although in
some cases the killing procedure is the same.
• Minimizing the risks of spreading the infection
Disease control measures require animals to be killed on farms to minimize the risk of
spread of disease and in some cases to protect public health. Using the Anoxia method,
animals are submerged under a blanket of Nitrogen-filled foam, which will render them
unconscious within tens of seconds. Compared to other culling methods, Human-to-Animal
H2A contact will be substantially reduced. This is because human handling is not part of the
actual euthanasia process itself. By reducing H2A contact the Anoxia method improves
biosecurity at the farm. Thus limiting the spread of infections and disease as well as
reducing the risk of human infections. This is a key issue to prevent larger scale outbreaks of
diseases through human interaction with diseased animals.
• Technical description of the Anoxia technique
The Anoxia method is based on the use of a high velocity jet nozzle installed in a cylindrical
stainless housing which creates a pressure differential across a mesh screen. This allows
nitrogen to pass through the unit and, with the introduction of soap in the environment,
creates large volumes of high expansion nitrogen foam, up to 300-expansion rate.
The Anoxia technique is based on producing high expansion - water based – foam, created
to deliver an anoxic gas (nitrogen). The source of the nitrogen gas is provided by either
pressurized bottles/tanks or created out of atmosphere by a nitrogen generator. The foam
nozzle itself consists of a spray nozzle and a pair of wire-mesh screens mounted inside a
stainless steel cylinder.
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The foam nozzle is connected to a soap dispenser that is connected to tap water. The water
and soap premix (3% soap) is pumped in and sprayed with a rotating high velocity spray
nozzle on the first Mesh using a pressure of 3,5 bar. Most tap water systems provide a
pressure of 3,5 bar, so unless the tap water pressure is below 3,5 bar, an additional
pressurized water reservoir (mobile water tank) is not needed. The premix is specially
designed for high and very high expansion that can build up foam up to 12m high.
The foam nozzle is also connected to a nitrogen supply source (nitrogen generator or bottle)
with a pressure of 4 to 8 bar. The nitrogen is released inside the closed body of the foam
nozzle. The pressure and the flow of the premix is tailored to the flow of nitrogen through
the nozzle in order to create a uniform flow of nitrogen foam. With a designed expansion
rate of 300:1 and a nominal premix flow rate of 2,5 litre per minute, the output is 0,75 m3 per
minute.
• Mobile Nitrogen generator
Depending on the demand of Nitrogen needed to apply the Anoxia method, there are two
options:
A. Using bottled Nitrogen
B. Applying a Nitrogen generator
Ad A: Bottled Nitrogen
This option can be applied in case the demand of nitrogen is limited, for instance to
euthanize small numbers of animals at the time. Nitrogen is widely available and can usually
be delivered in any quantity needed, at any given location.
Ad B: Applying a Nitrogen generator
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Nitrogen can be generated freely at your location, in a continuous and reliable way that only
requires a supply of compressed air. Generally speaking, there are two ways to make on-site
nitrogen. There is membrane technology and PSA (Pressure Swing Adsorption) technology.
Membrane Technology works by filtering oxygen from the dry compressed air stream via
hundreds of thousands of hollow, polymeric fibers each the diameter of a human hair to
produce gaseous nitrogen. The purity of the nitrogen (O2 Content) can be adjusted by
regulating the volume of air passed through the membrane.
PSA technology utilizes two towers that are filled with carbon molecular sieve (CMS).
Compressed air enters the bottom of the "online" tower and flows up through the CMS.
Oxygen and other trace gases are preferentially adsorbed by the CMS, allowing nitrogen to
pass through. After a pre-set time the on-line tower automatically switches to the
regenerative mode, venting contaminants from the CMS. Carbon molecular sieve differs
from ordinary activated carbons as it has a much narrower range of pore openings. This
allows small molecules such as oxygen to penetrate the pores and separate from nitrogen
molecules, which are too large to enter the CMS. The larger molecules by-pass the CMS and
emerge as nitrogen gas.
Anoxia Europe BV and Parker Hannifin, the world-leading manufacturer of nitrogen
generators, developed a generator that is specifically tailored to the needs of the Anoxia
technology. The generator has a nitrogen production that is sufficient for one foam nozzle,
is mobile and has been designed to work in the corrosive atmosphere of poultry houses.
The picture shows a Compair Hydrovane air compressor, with nitrogen generator and a
nitrogen storage tank. The system will be supplied at national electricity standards. The foam
nozzle has not been represented.
• Occupational Health & Safety
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Nitrogen is not a “poison” in the traditional sense. It presents a hazard when it displaces
oxygen, making the atmosphere hazardous to humans. Breathing an oxygen deficient
atmosphere can have serious and immediate effects, including unconsciousness after only
one or two breaths. The exposed person has no warning and cannot sense that the oxygen
level is too low. Occupational Safety and Health regulations require employers to maintain
workplace oxygen at levels between 19.5 and 23.5% because the human body is adversely
affected by lower concentrations. As the oxygen concentration falls below 16%, the brain
sends commands to the breathing control centre, causing the victim to be resuscitated, and
he or she risks cardiac arrest. Thus it is important that euthanizing with nitrogen gas foam is
done in an area with good ventilation to prevent human exposure to low levels of oxygen.
Oxygen monitoring devices can be used to assure the correct oxygen concentration in both
inside the foam bubble (<5%) and in the air that workers are exposed to (19.5 – 23.5%). Gas
cylinders are heavy and should be handled with care! They can turn into projectile missiles if
a drop or being knocked over causes damage to the pressure valves. Thus it is important
that they are held in place with a sturdy mount while in use.
Atmospheric oxygen
concentration (%)
Possible results on humans2
20,9% Normal
19,0% Some unnoticeable adverse physiological effects
16,0% Increased pulse and breathing rate, impaired thinking and
attention, reduced coordination
14,0% Abnormal fatigue upon exertion, emotional upset, faulty
coordination, poor judgment
12,5% Very poor judgment and coordination, impaired respiration that
may cause permanent heart damage, nausea, and vomiting
<10% Inability to move, loss of consciousness, convulsions, death
PART 2: APPLYING THE ANOXIA METHOD
A. Euthanizing a stock of 6.000 chickens within an 6 hours time frame
To demonstrate how the Anoxia method could be applied during an emergency, you will
find a detailed description of the procedure of euthanizing a flock of 38.000 floor bred
broilers by a small team of 5 well-trained and experienced poultry workers (under the
supervision of 1 veterinarian and one veterinary extension worker) within a time frame of 8
hours. It includes a full stocktaking of all components needed to carry out the procedure.
B. The euthanasia procedure
Four disposable containers are assembled and placed on a pallet and a liner is placed into
the container. The surplus of the liner is pulled over the outside of the container, through
the filling spout of the container.
2 SOURCE: Compressed Gas Association, 2001.
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The maximum loads are 40 birds at a time (creating a layer of max 10 birds per container)
equally divided into the liner of each container in order to prevent the stacking living
animals. When the first layer of birds has been loaded, the nitrogen foam is inserted in the
liner, submerging the birds in foam. All oxygen in the bag is replaced by animals and foam
filled with >98% nitrogen. The foam layer on top of the animals works as a seal. It prevents
the gas from escaping, even though the bubbles underneath the entrance might break by
movement or wing flapping. The filling sprouts of the big bags are closed tightly with a knot
to prevent the nitrogen from escaping.
Submerging birds under a layer of foam hardly affects the physiology or behavior of the
birds until they are unconscious. The physical reaction of the animal starts after the bird is
unconscious. After 9 to 16 seconds, the birds show Ataxia/loss of posture, followed by an
onset of wing flapping for 14 to 16 seconds. Time to cessation of movement is between 51
to 65 seconds.
After 1,5 minute, the filler sprout can be opened and the liner can be filled with a next layer
of birds. The procedure can be repeated until each liner is filled to a capacity of around 100.
The liners are now closed with the rip tie and all the remaining plastic of the liner is put back
through the filling sprout. Pulling firmly (by two persons) on the four corner loops of the big
bag, the bag slides over the liner, leaving the liner on the pallet for safe transportation and
storage. The big bags are placed on the next four pallets and the procedure is repeated until
all birds are euthanized. After the process, all pallets and liners are disinfected, ready for
pickup.
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C. Suitability
The Anoxia method can be applied to the following poultry species:
• Hens – puppets, laying hens, broilers, breeding stock
• Turkey – rearing, meat, breeding stock
• Ducks – rearing, meat, breeding stock
• Other – geese, pheasants, Guinea fowl, Partridges, Quail
D. Visualisation of the Standard Operating Procedure
1.
Set up 4 disposable
containers per nozzle and
insert 4 sheets of hard
plastic into the side pockets.
2. Place the disposable
container on a disposable
plywood pallet for easy
transportation and storage
3. Insert the plastic liner
through the snout of the
disposable container
4. Connect the water hose to
the tap water system
(minimum pressure needed
is 3,5 bar) to the soap
dispenser. Place the soap
dispenser into a canister
with soap concentrate and
set the dispenser on adding
3% foam concentrate. In
case tap water cannot be
applied, connect a pressure
vessel filled with water to
the soap dispenser.
5. Connect the foam
dispenser to water valve of
the nozzle(s).
6. Connect the nitrogen
source to the gas valve of
the nozzle(s)
7. Place the gas foam
nozzle(s) horizontally away
from the snout of the
container
8. Enter 10 birds at the time
into the liner of each
container
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9. Anoxia foam
Allow 1 m3
of Anoxia foam per 250 kg (125) birds. One m3
of foam
sublimates to approximately 1,26 Kg of Nitrogen gas. The Nitrogen can
either be sourced by bottles or by a Nitrogen generator
10. Oxygen monitoring device
EU and OIE standards require the monitoring of gas concentration. The
residual oxygen levels inside the foam should be maintained at least 98%.
11. Start creating foam, but
before turning the nozzle
to the snout of the
container, check the gas
pressure (3,5 to 4 bar) and
the water pressure (3,5
bar) and adjust the
pressure of both water
and soap until solid foam
is formed.
12. Measure the residual
oxygen level with the
oxygen sensor. The
residual oxygen level in
the top layer of the foam
should be at not more
than 2% (indicating a
nitrogen concentration of
>98%).
13. After the settings are
correct and solid nitrogen
foam is created, turn the
nozzle towards the snout
of the container and spray
the foam over the
animals. Repeat this
procedure for each
container. This will take
approximately 30 seconds
per bag
14. After the container is
completely filled with
foam, close the snout of
the container with the
attached cord. Keep the
bag closed for at least 1
minute until all
movements in the bag
have stopped.
15. Open the bags and start
refilling them with 10
birds.
16. Repeat this procedure 10
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times, until the bags are
filled with 100 dead
poultry carcasses.
17. Seal each liner securely
with a rip tie
18. Remove the container by
gently sliding it of the liner
on the pallet in vertical
direction
19. Replace the pallets with
filled liners and repeat the
procedure.
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PART 3: TECHNICAL DISCRIPTION MATERIALS
The materials used for this operation include all technical components needed to carry out
the euthanasia operation. Besides these, the materials list includes sufficient personal
protection equipment for 10 persons, as well as components to carry out disinfection. For
easy storage, all materials and components are delivered on a pallet, in cardboard boxes.
Complete sets of instructions for the use of various components are included in the form of
a user manual as well as an online version.
A. Description of the nozzle system
• Foam generator (Nozzle)
• Monitoring equipment for water pressure and a nitrogen regulator
• Soap dispenser, adjustable to ad 1 – 5% soap
• Dynamic oxygen monitoring device, to measure the residual oxygen levels inside
• The foam should be maintained at least 98% of nitrogen
B. Description of the disposable container system
The Anoxia method is based on the use of disposable materials to avoid risks of spreading
infections through the reuse of equipment. The use of disposable containers is a simple and
effective application to contain and dispose carcasses safely. Closed bags on disposable
pallets are easy to clean and disinfect and because the animals are safely stored in the
strong plastic bags, they are concealed during storage and transportation. Once assembled,
a 1m3 disposable container is created that enables processing up to 100-birds/250 kg. The
disposable container system consists of the following components.
Disposable container with an open bottom and 4 side pockets
• A Flexible Intermediate Bulk Container FIBC made of thick woven polypropylene with four
lifting loops
• The big bag has double walls or pockets that are used to stabilize the disposable container
with 4 hard plastic supports (included)
A strong polyethylene liner that is placed inside the big bag
• 3 meter long and a radius of 1 meter
• Thickness of 80/160 gr, strong enough to withstand penetration
• Capacity to contain 6 - 125 birds (max 250kg,) depending on choice of thickness
Disposable pallet
• Lightweight plywood pallet 100 x 120 cm, for one-time-use only
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Rip ties
• Special rip ties provided with a QR code to simplify traceability and recognition
C. Description of the Personal Protection and disinfection Equipment
To prevent human infection and the spread of infection through human trafficking, the
disposable container system is accompanied with a complete set of disposable Personal
Protection Equipment for suitable for 10 persons including:
• XL size protective coveralls
• 3M respirators, class type N95
• Surgical gloves
• Working gloves
• Durable shoe covers
• Protective glasses
• Plastic aprons
D. Description of the additional items
In addition easy –to-use items are included that are particularly useful, like:
• Duct tape, to adjust the size of the one-size-fit-all coveralls to the size of the person
wearing the coverall
• Marker pens, to prevent miscommunication by visualizing the name of the person
wearing the coverall
• Ziploc bags, to tape on the coverall, enabling the person to use side pockets
• Colored biohazard bag, to dispose the PPE safely after use
• 1 role of barrier tape, to demarcate the working area (in case the procedure is carried
out in the open)
• Netting, to create a pen, secondary fencing, or herd birds
E. Description of the Disinfection equipment
To enable safe transportation of carcasses, humans and materials, before exiting the
euthanizing area, a simple disinfection set is included, containing a back spray unit and 1 kg
of Virkon S disinfectant
• 2 foot dip containers
• 1 kg powdered Virkon S disinfectant
• 1 manually operated back pack sprayer
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PART 4: BACK-UP
A. Alternative Backup System
In case a backup system is needed to replace the production of nitrogen gas foam,
alternatively CO2 with a concentration of at least 70% can be used to cull the birds.
Alternative procedure using vaporized CO2.
1. Place the gas tube in the base of the bag and start adding vaporised CO2 into the bag
with a maximum pressure of 1.2 bar, to prevent freezing.
2. The concentration of CO2 should be periodically checked. It should be at least 70%
(residual oxygen level > 6.3%) within 20 cm of top of bag.
3. Once the correct concentration of CO2 is achieved, birds can be caught and placed in
the bag.
Alternative procedure using dry ice (solid CO2)
1. Place some used litter, hay or straw in the base of the bag to cover the solid dry ice. This
prevents any risk of the birds coming into contact with the dry ice and will not affect the
vaporization of the gas.
2. Once the correct concentration of CO2 is achieved, birds can be caught and placed in
the bag.
3. The concentration of CO2 should be periodically checked. It should be at least 70%
(residual oxygen level > 6.3%) within 20 cm of top of bag.
4. If it falls below 70% then additional dry ice pallets should be added and allowed to
vaporize
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Applying the Anoxia Method for culling small poultry flocks on organic farms

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