Outbreaks of animal diseases are well documented throughout modern history. Major outbreaks have damaging consequences for animal welfare, for the industry and often cause major disruptions in food supply, especially within the poultry industry. In order to avoid these consequences, killing methods and techniques have been developed to kill poultry on farm, as well as development dedicated emergency plans, guidelines, procedures to shoulder efforts to reduce and prevent large-scale outbreaks. Despite all these efforts in the past, outbreaks continue to occur. New, integrated methods for culling and disposal must be developed to combat outbreaks that cannot be mitigated or prevented by vaccination. These methods should be capable of supporting large-scale, quick culling campaigns and cadaver disposals without further spreading of diseases, transfer to humans, or putting a liability on the environment. In the EU, although Regulation 1099/2009 covers culling operations, the present techniques often are not compliant, or are often applied in an improper way. On March 17, 2014, Dr. Lotta Berg, one of Europe’s leading experts in this field and Swedens' representative within the European Food Safety Authority EFSA, presented at Neiker Tecnalia in Victoria-Gasteiz (Spain) her vision on emergency response, referring to the EU Directive EU 1099/2009. She covered in her presentation the following subjects: • Different types of poultry and poultry production • Reasons for euthanasia • Large‐scale emergencies • Contingency planning • Monitoring animal welfare at on‐farm killing • Critical points, follow‐up and reporting • Different methods in practice • Non‐emergency euthanasia Dr. Berg concluded in her presentation that the Anoxia technique (N2 gas foam) is applicable for killing poultry on small-, medium- and large-scale poultry operations.

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Lotta Berg
Dept. of Animal Environment and Health
Swedish University of Agricultural Sciences, Skara
Lotta Berg
Dept. of Animal Environment and Health
Swedish University of Agricultural Sciences, Skara
Presentation given at Neiker, Vitoria Gasteiz, Spain, March 17th 2014
Background
Veterinarian
Researcher
Teacher
Previously: Veterinary Officer at the Swedish Board of
Agriculture (National Competent Authority for animal
health and welfare)
Contact Point 1099/2009 (EU Regulation)
Structure of this presentation
Different types of poultry and poultry production
Reasons for euthanasia
Large scale emergencies
Contingency planning
Monitoring animal welfare at on farm killing
Critical points, follow up and reporting
Different methods in practice
Non emergency euthanasia
Presentation
Pdf hand outs will be available afterwards.
Without some of the pictures…
Photos from many different countries.

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Introduction
Different types of poultry
Broilers, laying hens, turkeys, ducks, geese
Different behaviour
Different biology
Different housing systems
Different methods of euthanasia?
Biology and behaviour
Body size and conformation
Flying?
Running?
Sensitive to carbon dioxide?
…
Today’s presentation will focus on layers and broilers, but
often relevant also to other types of poultry.
Reasons for euthanasia
Planned
Unwanted dayold chicks (layer males, malformed chicks)
End of lay hens (entire flocks)
Surplus animals (e.g. breeding males in broiler breeder
flocks)
Emergencies
Single sick or injured birds
Entire flocks suffering from disease
Entire flocks suffering from transmissible,
epidemic/zoonotic disease (e.g. Newcastle, Avian Influenza)
Single
birds
Single birds
Most important: locate and euthanize
How?
Neck dislocation
Preferably after stunning
Not too many animals
Large scale emergencies
Non planned
Often large number of birds
Potential risk of spreading the disease
Disease control and eradication
purposes

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Prevention!
Feed and water
Rodents and wild birds
Poultry bought
Contact with other flocks
Visitors
Veterinarians
Advisors
Neighbours
…
Owner/Farmer/Staff
Transport, equipment
Wind
…
Biosecurity
Rodent and wild bird
control
Visitor control
Farmer/staff control
Poultry control (surveillance,
sampling)
Contingency planning
Is it possible to plan for the unexpected?
Yes – possible and absolutely necessary!
Plans for emergency killing of whole flocks, i.e. depopulation
Flocks infected and diagnosed with a specific disease
Flocks with an undiagnosed disease
Pre emptive culling
Welfare culling (Culling of flocks to avoid over crowding, when
slaughter is not an option and running out of feed…)
Contingency planning
Conditions will vary!
Reason for killing
How urgent?
Zoonosis? (Worker’s safety)
Number of birds
Age of the birds
Type of birds
Type of housing
Methods available
Staff available
Cost
…
Having just one “master
plan” is not enough!
Species and method specific
standard operating
procedures (SOP:s) are
necessary.
Contingency planning
Contingency planning is an overall responsibility of the
authorities.
Also relevant at the farm level.
Prepare for the unexpected!

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Contingency planning
People involved
As few as possible if dealing with a zoonosis
As little human bird contact as possible if a zoonosis
People available
Who has relevant knowledge?
Who is paying…?
Farmer, veterinarian, staff
Responsibilities
Who is in charge?
At the central/regional level: Competent authorities
Who makes decisions on what method to apply, how to do
it and when?
At the farm:
Again – who makes decisions? Who is supervising
biosecurity and animal welfare?
Commercial companies specialising in such operations?
Make sure to settle an agreement on responsibilities
Media attention – part of the
contingency planning
Ethical issues
Newspaper coverage
TV cameras…
Discussions in social media
Who should handle this discussion?
The individual farmer?
The authorities?
Someone else?
Animal Welfare considerations
The main task is always to prevent further spread of
disease (to humans or animals).
Biosecurity
Speed is often essential
Appropriately trained staff available?
Relevant equipment available?
Occupational hazards?
Stressful both for the farmer and official staff
Animal welfare is an inherent aspect
Decision making tree?
One possibility – just an example:
…and so on…
Laying
hens
Infected
<50 birds
50 5000
birds
Status
unknown
Wait for
test results
Non
infected
>5000
birds
Carbon
dioxide
Animal Welfare considerations
EU legislation 1099/2009
Various guidelines
OIE: “Methods applied should result in immediate death
or immediate loss of consciousness lasting until death.
When loss of consciousness is not immediate, the
induction of unconsciousness should be the least aversive
possible to the animal.”

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Animal Welfare considerations
Whenever possible: use methods that are the
same as, or similar to, methods used for
standard on farm killing of sick or injured birds
or flocks unfit for slaughter.
Because: equipment is readily available, staff
experienced and knowledgeable.
Not always possible, because of the numbers
involved.
Animal Welfare considerations
Animal welfare aspects should be included in contingency
planning and emergency preparedness:
Organisation
Training
Reporting
Follow up
Detailed provisions on choice of method depending on
species, number etc
Standard Operating Procedures (SOPs) for each method.
Animal Welfare considerations
The entire depopulation operation must be monitored
from an animal welfare point of view.
‘Lessons learned’ should be applied in the future.
Killing large numbers of animals is
not an easy task, mentally…
For large scale operations
Staff rotation and counselling
Farmer participation??
Police
Media
On farm Animal Welfare monitoring
OIE Terrestrial Animal Health Code:
Official veterinarian in charge
OV appoints personnel and provides guidance
At each farm: Specialist team, with a team leader and
including a veterinarian (or with constant access to
veterinary advice).
Team leader and veterinarian must have animal welfare
assessment competence.

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On farm Animal Welfare monitoring
EU Regulation 1099/2009
Competent authority is responsible for depopulation for
disease control
Shall establish an action plan to ensure compliance with
animal welfare regulation.
Exceptional circumstances?
Human health at risk? Substantial delay?
Competent authorities can allow for derogations, on a
case by case basis.
Does not substitute proper planning!
On farm Animal Welfare monitoring
Public demand for transparency
EU requirement: reports on depopulation should be
made public online.
Reason for depopulation
Number of animals
Species
Methods used
Any difficulties?
Solutions?
Monitoring
“Observe and check the
progress or quality of
(something) over a period
in time, keep under
systematic review”
Oxford Dictionary
Monitoring
Not just watching and keeping records –
Taking relevant corrective action when necessary
Learning from current and previous difficulties
Authority to act!
Critical Points
Animal handling prior to killing
Where will the animals be killed?
Stun quality
Effectiveness of the method used to render the birds
unconscious and dead
Confirmation of death
Prior to carcass disposal
Critical Points
Everybody involved should know their roles and
responsibilities
Everybody should participate in monitoring…
But it is recommended to have a specific person in charge
of overall monitoring of animal welfare on site.
This person must have knowledge about
Animal behaviour, physiology, signs of pain
and suffering, etcetera.

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Practical aspects in general
Animal handling prior to killing
Animals should be handled as little as possible
Staff should know how to handle animals
Personal protective clothing
No unnecessary disturbance from the media etc.
Practical aspects in general
Verify that the necessary equipment for stunning and
killing is functioning.
Monitor stun/kill quality frequently
Cleaning and maintenance, when necessary
Verify gas concentration when relevant
Practical aspects in general
Verify death, for each individual bird
Large numbers, great haste…
Systematic approach
Combination of different indicators
Absence of heartbeat
Cessation of respiration
Absence of movement over a longer period
Presence of rigor mortis
Checklists
To be developed by authorities, advisory/extension
services or producers’ organizations.
Methods for on farm depopulation
Aspects to consider, for example:
Reason for killing
How urgent?
Zoonosis? (Worker’s safety)
Biosecurity
Number of birds
Age of the birds
Type of birds
Type of housing
House location and surroundings
Owner attitude
Methods available
Staff available
Cost
…

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Barbiturate injections
For veterinary use only
Useful for testing of individual birds, where physical
trauma is detrimental and gas too time consuming.
Very time consuming for larger numbers of birds.
Difficult to inject correctly:
Abdominal injection: birds do not have an abdomen (!).
But – birds have air sacks.
Intravenous injections: requires training, applicable mainly
for larger species.
Cervical dislocation
Neck dislocation by stretching and wringing (torsion) the
neck, so that the spinal column vertebrae are properly
separated (i.e. dislocated).
When properly carried out, the blood vessels will rupture,
and the bird will bleed under the skin.
Ensure proper separation.
Manually: no more than 70 birds per person/day
Manually: Bird weight maximum 3 kg
Cervical dislocation
Not really a stunning method
Preferable to stun the birds first (usually by a blow to the
head)
Stick/ truncheon

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Mechanical neck dislocation:
Broiler breeders
Remember –
do not just
break/crush
the neck –
stretching
and torsion is
important.
Mechanical neck dislocation:
Geese
“Home built” tool for assisting neck dislocation in geese.
Remember stretching plus torsion.
Blow to the head
V shaped hook for neck
dislocation
Hard plastic stick
(truncheon) for blow to
the head
Captive bolt gun for poultry
A bolt that kills
Two person operation
“Cash Poultry killer”
Head only electrical stunning
Followed by neck dislocation
Gas methods
Carbon dioxide
Anoxia (Nitrogen)
Method of gas administration
Gas in container
Liquid – gas
Foam – gas

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Mode of action: CO2
Hypercapnia + hypoxia
Lowers pH
Sedative effect
Heavy gas (heavier than air, will build up from the floor)
Mammals and birds have chemoreceptors for CO2
It is unpleasant (aversive) to inhale CO2
Gasping, head shaking
Less aversive at low concentrations:
Better to start at lower concentrations and gradually increase
the concentration (but still relatively rapidly).
Carbon
dioxide
Mode of action: nitrogen
Anoxia
Outcompetes oxygen
Odourless
No chemoreceptors, not aversive.
Will mix with air
Difficult to contain
Anoxia leads to convulsions
Always a gradual process
Nitrogen
Method of distribution
Gas, ambient temperature (CO2 in small amounts),
welding gas (CO2 + argon)
Liquefied gas, very cold (CO2)
Dry nitrogen ice (very cold)
Foam containing the gas (nitrogen)
Worker’s safety.
These gases are as lethal for humans and other animals as
they are for poultry!
Method of distribution
In containers
+ Lower amount of gas needed.
+ Controlled, the dead birds are already collected.
Staff has to catch the birds first.
Whole house
+ No catching or crating of live birds needed. Minimal human
live bird contact.
+ Dead birds are easy to collect.
Higher amount of gas needed.
House must be reasonably sealable
Carbon dioxide in containers
Small flocks. Wheelie bins or small containers.
In this case, the container is filled
with gas before the birds are
placed in it.
Carbon dioxide in containers
Medium size flocks, dumpsters
In this case, the
container is filled with
gas before the birds are
placed in it.

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CO2 or CO2+argon in containers
In this case, birds
are placed in the
container before
the gas enters it.
Carbon dioxide whole house
Medium large flocks
For emergency depopulation, but also end of lay hens
Commercially available
Preparations
Calculate the volume of the building
Formula aiming at 80 % CO2:
[ house volume (m3) x 1.8 x 0.80 ]
Order the gas
Order dumpsters for the carcasses
Drill a hole in the wall and insert a permanent tube – if
not already present
Seal the building – but do not over seal
Why aiming at
80 %?
Margins!
Leakage
“Overkill”…
The leading in tube
High pressure!
Better to install the tube when building the house…
Seal the building
Remember: heavy gas.
When adding 80 % CO2, air will have to escape – do not
over pressurize the building.
CO2 can leak to adjacent compartments – seal properly
(egg belts, manure systems etcetera)
Make sure that the birds are not hit
by the cold high pressure gas beam
Fence off the area near the inlet.
Empty the water line – freezing.

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Safety
Make sure that nobody is still inside the house
Turn off the ventilation (not earlier!)
Connect the hose and turn on the
tap
Beware – the equipment gets very cold.
Monitor the process Snow fog
Wait sufficiently long time
Gas distribution time: 5 15 minutes, depending on house
size.
Wait at least 30 60 minutes before turning on the
ventilation again. Open the doors.
Wait until the CO2 has been removed from the building
Remember:
heavy gas: remain
standing up!
Inspect the result

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Ensure that all birds are dead.
Broilers
Turkeys
Nitrogen
Dry ice or under compression or N2 in gas foam
Truck delivery of compressed N2 (trial only). Not a heavy gas
– sealing crucial.
N2. Trial
only!
Difficult to seal commercial poultry houses enough. Difficult
to achieve low enough oxygen concentration.
Nitrogen in gas foam
Small, medium and large farms
High expansion foam filled with gas (could be any type of gas).
Large bubbles that rupture when coming in contact with the
birds.
Makes it possible to contain the gas where it is needed, i.e.
around the birds.
Commercially available (n2gf.com)
Not specifically mentioned in 1099/2009, but inert gases are
allowed, and method of administration is not specified.

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Equipment needed:
• Disposable containers or used in the
whole house.
• Foam nozzles.
• Compressed nitrogen
• High expansion foam detergent.
• Water tanks? If large amounts of
water needed.
• Sets of regulators and measuring
equipment.
N2 gas foam N2 gas foam
Possible to use also in house, but not first choice.
Fire fighting foam
Not legal in the EU (1099/2009), but used in the US.
Bubbles do not contain any specific gas (just air).
Bubbles are small and will cause occlusion of the
respiratory tract.
Birds die from asphyxiation.
Not recommended from an animal welfare point of view.
Ventilation shut down
Not legal in the EU (but sometimes used anyway, as a last
resort).
Shut ventilation down to increase ambient temperature.
Birds die from hyperthermia.
Very slow for birds with relatively low metabolism and in
cold climates, slightly more rapid for birds with high
metabolism and in hot weather.
Not recommended from an animal welfare point of view!
Summary
For large scale operations:
Whole house CO2
Nitrogen gas foam in containers (or in the house)
For medium or small operations:
Nitrogen foam or CO2 in containers
Or manual methods…
End of lay hens, which are not suitable for slaughter…

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Non emergency killing of small
numbers of poultry
Stunning + manual neck dislocation
Stunning + mechanical neck dislocation
Electrical dry or waterbath stunning + bleeding
Non emergency killing of large numbers
of poultry
Gas methods as described above.
Non emergency killing of large numbers
of poultry
CO2 flow container / tunnel
87
• Developed by the
Danish company
”Chickpulp”
• Producer-owned
• Catching staff
included, if asked for
• 3500-4000 birds/hour
• End product used as
mink feed
• More manual
handling of live birds
• Difficult to sanitize
the equipment.
• Difficult to multiply
rapidly…
88
Design
Minimum 60 + 120
seconds in container,
then maximum 60
sec to macerator
89
The hens become unconscius and die in
the container
Window for
inspection on
the other side.
CO2
meter
90
The dead hens are
transported from the
container to the
macerator

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91
Vehicles and equipment…
Everything is stored
on the vehicle.
Cold transport truck
picks up the pulp.
The vehicle brings
the gas tubes, and
its own diesel
generator for
electrical power.
Hygiene,
biosecurity!
Further reading
Berg, C., 2009. Poultry welfare problems related to avian influenza and other contagious diseases. World’s
Poultry Science Journal, book of abstracts, WPSA Poultry Welfare Symposium, Cervia, Italy, 18 22 May, p70 74.
Berg, C., 2012. The need for monitoring farm animal welfare during mass killing for disease eradication
purposes. Animal Welfare, 21:357 361.
OIE Terrestrial Animal Heath Code. Chapter 7.6. Killing of animals for
disease control purposes.
http://www.oie.int/index.php?id=169&L=0&htmfile=chapitre_1.7.6.htm
(In Spanish: http://www.oie.int/es/normas internacionales/codigo terrestre/acceso en
linea/?htmfile=chapitre_1.7.6.htm)
European Union 2009. Council Regulation (EC) No 1099/2009 of September 2009 on the protection of animals
at the time of killing. http://ec.europa.eu/food/animal/welfare/slaughter/regulation_1099_2009_en.pdf
(In Spanish: http://eur lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2009:303:0001:0030:ES:PDF)