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Guidelines for stunning techniques for avian food animals, including ratites

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Chickens -broilers/roasters

Electrical stunning

Multiple bird electrical stunning systems - operational procedures and parameters

For most electrical multiple bird stunning systems, the birds are shackled inverted when still conscious prior to stunning; therefore shackling must be done in a manner to minimize distress and pain to the birds.

Shackles, shackling, shackle line, fractures, bruising and breast bars

Shackles, shackling, shackle line, fractures, bruising and breast bars

Description for chicken handling/shackling

Firstly
A chicken is shown extensive leg and wing bruising from injuries probably sustained from handling/shackling; then
A chicken shackle is shown; thirdly,
The shackling step of poultry is demonstrated and lastly
Shackled conscious chickens are shown.

Source: CFIA and Food and Agriculture Organization of the UN (FAO)

Conductivity

Conductivity of Water and Saline Solutions
Weight (g of salt/liter) ppm (mg/L) Conductivity (H2O and NaCl)
0.0001 1 2.2
0.001 10 21.4
Example, Saskatoon Drinking Water 27 57
0.01 100 210
0.1 Table Note 1 1000 1990
1.0 Table Note 2 10000 17600

Table Notes

Table Note 1

Waterbath concentration

Return to table note 1  referrer

Table Note 2

If you spray the shackles at 1 g/liter it will greatly increase conduction

Return to table note 2  referrer

Waterbath stunning

Waterbath single phase stunner

Diagram of a single phase electric waterbath stunner

Diagram of a single phase electric waterbath stunner. Description follows

Description for Diagram of a single phase electric waterbath stunner

Important elements of an electrical waterbath stunning system and equipment are described for this type of stunner and include the following steps:

  • the shackles for the legs of the bird are clean to make the best contact with the legs
  • the presence of an entry ramp allows each bird to swing into the bath better
  • the bird is immersed up to the shoulders to ensure good contact with the electrified water for the stun which will cause a seizure when done correctly
  • the ground electrode is in constant contact with the shackles to complete the electrical circuit
  • the bird is bled soon after exiting the stunning equipment
  • the birds bleeds within 90 seconds so no conscious bird enters the scald tank

Source: CFIA and Humane Slaughter Association

Entry to a waterbath stunner

Pre-stun shocks:

Pre-stun shocks are not acceptable and are caused by:

Minimize pre-stun shocks by:

Wing flapping is caused by:

Wing flapping can be significantly reduced by:

Plate or grid systems for electrical stunning of birds

Other multiple bird systems include single plate (grid) and two phase (step) plate (grid) systems:

Diagram of an electric wet plate single phase stunner
Diagram of an electric wet plate single phase stunner. Description follows.
Description for Diagram of an electric wet plate single phase stunner

Key elements of an electric plate single phase stunner system and equipment are described in the diagram of this type of stunner and include the following key steps for proper stunning:

  • the shackles for the legs of the bird are clean to ensure the best contact with the legs
  • the presence of an entry ramp allows each bird to swing into the bath better
  • the bird’s head and eye make contact with the electrified plate for the stun which will cause a seizure when done correctly
  • the equipment can adjust for short and large birds
  • the ground electrode is in constant contact with the shackles to complete the electrical circuit
  • the bird is bled soon after exiting the stunning equipment
  • the birds bleeds within 90 seconds so no conscious bird enters the scald tank

Source: CFIA and Humane Slaughter Association

Two phase two plate electrical multiple bird stunner

Diagram of an example of a two phase (or step) electric stunning plate system using a combination of DC pulsed current for the first wet plate and AC sinusoidal current for the second dry plate
Diagram of an example of a two plate system. Description follows.
Description for Diagram of an example of a two plate system

Elements of the two sections of an electric plate two phase stunner system are described in the diagram of an example of a two plate system and include the following steps: the bird enters the first step or the Direct Current phase for this wet plate section and then enters the second step or the Alternating Current phase for this dry plate section in order to complete the stunning process.

Source: CFIA

Table of preventive measures to consider for multiple bird electrical head-to-body stunning systems
Outcome Parameters to include in preventive measures

Generalized epileptiform seizure

  • Reversible for frequencies greater than 50 Hz
  • Irreversible for frequencies equal to or less than 50 Hz

Minimum current amperage, voltage, frequency, duration of stun

Maximum shackle duration, stun-to-stick interval

Frequency of calibration of equipment

Prevention of pre-shocks

Immersion of birds up to base of wings

Based on Welfare of Poultry at Slaughter Workshop, Mohan Raj

Head-Only electrical stunning

Hand-held head-only electrical stunning

This type of electrical stunning device is often used for small birds, culls, or in plants using very slow line speeds.

Tongs or similar device

To ensure adequate current flow, the electrodes of the tongs or the device must:

If not done properly the birds may have electrically induced seizures or be electrically immobilized without losing sensibility and be able to feel pain.

Target location for hand-held device placement (Figure a)
target location for placement (Figure a) of handheld electrical stunning devices on the head of a chicken between eyes and ears to span the brain
target location for placement (Figure a) of handheld electrical stunning devices on the head of a chicken between eyes and ears to span the brain

Brain
Located in the centre of the head (skull), medial to and just behind the eyes.

target location for placement (Figure a) of handheld electrical stunning devices on the head of a chicken between eyes and ears to span the brain
Figure (a) target location for placement (Figure a) of handheld electrical stunning devices on the head of a chicken between eyes and ears to span the brain

Stunning

Figure (b), (c) hand-held head-only electrical stunning equipment
Figure (b)  (c) hand-held head-only electrical stunning equipment
placement of hand-held equipment (e) on head of chicken spanning the brain
Figure (d) correct placement of hand-held equipment on head
placement of hand-held equipment(e) on head of chicken spanning the brain
Figure (e) correct placement of equipment on head of chicken

Source: Osten Johansson Maskinteknik Stinsgatan

Automated head-only electrical stunning

A current system for head-only automated electrical stunning uses an automated shackling process after stunning.

Key operational points
Restraining cones with birds prior to stunning and subsequent automatic shackling after stunning (Source: TopKip BV)
and automated shackling after stunning of each bird
chickens in individual cones prior to automated individual stunning
Table of preventive measures to consider for head-only electrical stunning parameters
Outcome Parameter to include in preventive measures
Generalized epilepiform seizure, reversible stunning

Minimum current, voltage, frequency, duration of stun

Maximum stun-to-stick interval

Frequency of calibration of equipment

Prevention of pre-stun shocks

Position and contact surface area of the electrodes

Based on Welfare of Poultry at Slaughter Workshop, Mohan Raj

Diagram of stun to stick requirements for reversible (simple) stunning parameters
Diagram of time interval of unconsciousness relative to stun to stick timing. Description follows.
Description for Diagram of stun to stick requirements for reversible (simple) stunning parameters

Diagram of time interval of unconsciousness relative to stun to stick timing for reversible stunning of all food animals during slaughter that shows the ideal time to bleed the animal after the stun to ensure the animal remains unconsciousness until it dies from the bleeding slaughter step.

Source: Mohan Raj, Welfare of Poultry at Slaughter Workshop

Recommended parameters for electrical stunning methods

Tables of electrical waterbath stunning parameters for poultry in accordance with World Organisation for Animal Health (WOAH; founded as Office International des Épizooties (OIE)) recommendations

Minimum current when using 50 Hz is as follows:
Species Minimum current (milliamperes per bird)
Broilers 100
Layers (spent hens) 100
Turkeys 150
Ducks and geese 130
Minimum current when using high frequencies is as follows:
Frequency (Hz) Minimum current (milliamperes per bird)
Chickens Turkeys
From 50 to 200 Hz 100 mA 250 mA
From 200 to 400 Hz 150 mA 400 mA
From 400 to 1500 Hz 200 mA 400 mA
Table from European Union Legislation (1099/2009) mandatory electrical parameters for electrical waterbath stunning equipment (average values per animal of amperage)
Frequency (Hz) Chickens Turkeys Ducks; geese Quails
< 200 100 mA 250 mA 130 mA 45 mA
200 - 400 150 mA 400 mA Not permitted Not permitted
400 - 1500 200 mA 400 mA Not permitted Not permitted
Table of head-only electrical stunning parameters (hand-held or automated equipment)
Chicken Turkeys
240 mA 400 mA

Based on Mohan Raj, Welfare of Poultry at Slaughter Workshop

Controlled atmosphere stunning (CAS)

CAS systems using different mixtures of CO2, Argon and O2

Table of examples of gas mixtures used internationally in different systems
Gas mixtures (examples) Induction phase Final phase
CO2 with air 30% - 40% 60% - 100% CO2
CO2 with O2 40% maximum + 30% enriched O2 (gradually removed in multiple stages) > 40% (in multiple steps) + removed O2
Argon, nitrogen (or other inert gases) with air 90% Argon with air
Residual O2 does not exceed 2%
No change
CO2 and Argon (or any other inert gas mixture in air) 30% CO2 and 60% Argon with air
Residual O2 does not exceed 2%
No change

Low atmospheric pressure systems (LAPS)

Modules with birds loaded into cyclinders (Source: TechnoCatch LAPS)

modules of chickens being placed into LAPS cyclindersSource)

Decompression cylinders (Source: TechnoCatch LAPS)

LAPS cylinders

Captive bolt stunning

Maintenance and operational issues for maximum effectiveness

Target location for captive bolt stunning

Target location for captive bolt stunning

Brain
Located in the centre of the bird's head (skull), medial to and just behind the eyes.

missing alt

Source: CFIA

Stunning

target location for captive bolt stunning of chickens at top of head behind location of eyes

Specific poultry class or species requirements for stunning methods

Mature chickens (culled breeders, end-of-lay broilers, end-of-lay laying hens)

Handling and/or stunning requirements unique to this class of chickens

Handle gently and support calcium depleted animals with fragile skeletons that fracture easily. Skeleton fragility is exacerbated by the lack of muscle conditioning from being housed in small cages for several months.

Electrical stunning

Captive bolt stunning

Controlled atmosphere stunning (CO2)

Rock Cornish Hens (immature broilers)

Handling and/or stunning requirements unique to this class of chickens

Electrical stunning

Captive bolt stunning

Controlled atmospheric stunning (CO2)

Turkeys

Electrical stunning

Waterbath stunning

Images of turkey shackles, shackling, shackle line and breast bars
example of shackles designed for turkeys
Turkey shackle
an example of using greater space between birds on shackle lines
Greater space on the line
an example of a breast bar to calm turkeys
Breast bar

Resistance and current to each bird

Resistance and current to each bird

Entry to the water bath stunner

Head-only electrical stunning

Brain
Located in the centre of the head (skull) medial to and just behind the eyes.

target location for placement of handheld electrical stunning devices on the head between the eyes and ears in order for the electrical current to pass through the brain of a turkey Source: Aviagen Turkeys Ltd

Direct the stunning device at a location that is just behind the eyes and just forward (rostral) to the ear openings.

Approach the bird's head from the top.
proper placement of hand-held electrical stunning device using the location between the eyes and ears of a turkey

Source: Aviagen Turkeys Ltd and CFIA

Controlled atmospheric stunning (CO2)

Captive bolt stunning

captive bolt stunning device using the location at the of top of the head and between eyes and ears of a turkey

Source: Humane Slaughter Association

Geese

example of a domestic goose

Electrical stunning

Waterbath electrical stunning

Head-only electrical stunning

The brain is located in the centre of the head (skull) medial to and just behind the eyes
target location and placement location of hand-held electrical stunning device just behind the eyes of a goose

Source: CFIA

Controlled atmosphere stunning (CO2)

Captive-bolt stunning

target location and placement location of a captive bolt pistol device on top of head of a goose

Source: Humane Slaughter Association (HSA) and CFIA

Ducks

example of a domestic duck

Electrical stunning

Waterbath stunning

Head only electrical stunning

Controlled atmosphere stunning (CO2)

Captive bolt stunning

Silkies and farmed game birds: Quail, Partridges, Pheasants

examples of farmed Quail
Farmed Quail
examples of silkie
Silkie
examples of farmed partridge
Farmed partridge
examples of farmed pheasant
Farmed pheasant

Electrical stunning

Specialized smaller size shackle equipment for quail
Example of specialized small shackles for quail
Alternative method of using small shackles hung from larger chicken shackles
Example of an alternative method using these small shackles to hang them from conventional larger chicken shackles

Controlled atmosphere stunning (CAS)

Ratites (Ostriches, Rhea and Emus)

Mechanical

Landmarks and approaches

[a]ratite - side view with arrow pointing to top of head for stun site

Legend - landmark for stunning ratites
Image Description
location of target for mechanical stunning equipment that should be pointed at the top of the head of an ostrich indicates the direction that the stunning device should be pointed and the entry point at the top of the animal's head

Mechanical stunning devices

Captive bolt
Recommended captive bolt equipment
Firearms

Electrical Stunning

Landmarks and approaches

[b]location of target where electrodes should be applied to sides of head of an ostrich for electrical handheld stunning

Legend - landmarks for stunning ratites
Image Description
indicates where the electrodes should be applied to each side of the animal's head. Indicates where the electrodes should be applied to each side of the animal's head.

Electrical stunning devices

Electrical stunning - Ratites
Birds Amperage Volts Frequency Time (sec)
Ostriches, Rhea, Emus Not hooded 0.12 - 0.4 230 - 300 50 - 60 3 - 4
Ostriches, Rhea, Emus Hooded 0.4 230 - 300 50 - 60 3 - 4

Shackling and hoisting

Sticking

Neck cutting and bleeding

automatic neck cutting equipment for poultry slaughter<
Neck cutting

Source: Food and Agriculture Association (FAO)

red birds which have missed the neck cutting step of slaughter and were not bled out prior to entering the scald tank
Figure 1
red birds which have missed the neck cutting step of slaughter and were not bled out prior to entering the scald tank
Figure 2

Source: CFIA

"Red" not bled bird compared to normal neck cut bled bird (Figure 1) and "Red" bird with neck not cut (figure 2)
Note: red birds are generally the smallest birds or the runts in a given lot of birds

Bleeding /sticking

Table of recommended time intervals between stunning and bleeding for all reversible stunning methods
Stunning method Maximum stun-to-cut interval
Electrical methods and non-penetrating captive bolt 10 - 15 seconds
CO2 60 seconds after leaving the chamber

(Based on WOAH guidelines)

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