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This study of a group of students was conducted in 2003, during the outbreak of H7N7 in Holland. Since a new series of outbreaks recently started in Asia, it's good to look back at the efficiency and effectiveness of the Dutch Emergency Response was.
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Colloqium Avian InfluenzaColloqium Avian Influenza
Introduction Problem definition and research questions Material and methods Results Discussion Conclusions
Avian Influenza in the Avian Influenza in the NetherlandsNetherlands
Evaluation of
culling methods used
during the
outbreak in 2003
Avian Influenza in the Avian Influenza in the NetherlandsNetherlands
Students: Judith Dietvorst
Marjan Kamphorst
Supervisors: Dr. Simon Oosting (WUR)
Harm Kiezebrink (HKI)
IntroductionIntroduction
Outbreak AI started March 2003 Culling AI-sensitive animals HKI Wageningen B.V. offered equipment and staff to cull poultry
Problem definitionProblem definition
Many animals have to be culled Not much knowledge about culling methods used during AI
outbreak in Netherlands
Research questions Research questions
What are the differences, comparing the methods used during the AI outbreak in the Netherlands in 2003, defined per farming system?
- capacity
- animal welfare
- feather spreading
- working condition
Research questions Research questions
What are the advantages and disadvantages of the culling methods used during the outbreak in the Netherlands?
Material and methods Material and methods
Culling methods used during outbreak- Electrocution: mobile slaughter lines with a waterbath
Material and methods Material and methods
- RF2: wheelie bin containers with a steal lit, filled with 60% - 80% Carbon Dioxide.
Material and methods Material and methods
- CAS: Controlled Atmosphere stunning. Tunnel with conveyor belt which goes trough stunning system. Combination of CO2, O2 and N2.
Material and methods Material and methods
- House gassing: 4 different companies worked with CO2. Gas is distributed out of the gas tank into the house through tubes.
Material and methodsMaterial and methods
Farms Located in Gelderse Vallei and Nederweert 22 observations on 11 farms and one
slaughterhouse Different farming systems
Material and methodsMaterial and methods
Four aspects of culling methods were measured:
1 Capacity: number of animals per hour that can be culled
2 Feather spreading: amount of feather spreading during culling was observed.
Scores were given from zero till four ( no spreading till extreme spreading)
Material and methods Material and methods
Observing periods Electrocution RF2 House gassing Catch X X Shackle X Put into container X Tubes brought into house X Culling process X X X
3. Animal welfare: divided in stress, back laying and live animals
Stress: observed animals on behavior like wing flapping, struggling, vocalization, head shaking and gasping. Scores were given on a scale of 1 to 10: a score of 1 is enormously stressful and 10 absence of stress
Material and methods Material and methods
Back laying: Counted dead poultry that were laying on their back. Could mean that poultry had to
struggle before they died.
Live animals: Counted surviving animals after the culling process.
Material and methods Material and methods
4. Working conditions:
- Catching birds out of house
- Walking with birds
- Shackling birds
- Use of CO2
ResultsResults
Culling method
Cage systems
Floor systems1
Average
RF2
9.5b, y 3.2x 6.3b
Electrocution
2.5a 3.0 2.8a
House gassing
13.3c,y 4.6x 9.0b
CAS
n.a. n.a. -
Average
8.4y 3.6x
1 Hobby animals excluded n.a. : not available
Capacity: x 1000 animals per hour
ResultsResults
Feather spreading
Culling method Score RF2
1.9b
Electrocution
2.7c
House gassing
0.9a
Different superscripts within column indicate significant differences (P < 0.05)
ResultsResults
Culling method
Catching Importing Culling
RF2
4.9 5.1b 5.4b
Electrocution
3.9 3.4a 3.9a
House gassing
- 4.8a 3.9a
Different superscripts within column indicate significant differences (P < 0.05)
Animal welfare
- Stress observations: scored as affected by catching, importing animals into culling operation and the culling as such
ResultsResults
Culling method Live animals % Incidence RF2 (n = 6) 0 0 Electrocution (n = 4) 2.3 3 House gassing (n= 11) 4.5 1 CAS (n = 1) 0 0
Animal welfare
- Back laying: assessed for the four house gassing systems. Average of 3.7% was found back laying after culling
-Live animals:
ResultsResults
Observations RF2 Electrocution House gassing
Catching live birds out of cages, floor or aviary system
+++ +++
Walking with live birds out of house
+++ +++
Use of CO2
++ ++
Shackling birds
++
Putting birds into container
++
+ = light work ++ = average work +++ = heavy work
Working conditions
DiscussionDiscussion
Capacity- Farming system
- Number of RF2 containers used
DiscussionDiscussion
Animal welfare- Subjective results
- Back laying: could be a measurement , but back laying is a result of convulsions.
- RF2 no live animals, but maybe not only by CO2.
DiscussionDiscussion
Feather spreading- Assumption made feathers could spread virus. Not
found in literature.
Working conditions- Cage system and house gassing: clearly heavier than
the other farming system. Rigor mortis takes place very soon after gassing.
ConclusionsConclusions
CapacityCapacity Advantage Disadvantage RF2 - the more containers
available the quicker the culling goes
- time needed to walk from house to RF2
- time needed to fill the container with gas
Electrocution - many animals could be shackled
- time needed to walk out of the house to electrocution system
House gassing
- a lot of animals in one time
- waiting after gassing before evacuators can do their work
CAS - not many animals could be
culled per hour
ConclusionsConclusions
Animal welfareAnimal welfare
Advantage Disadvantage
RF2 - quick death - no live animals
- sultriness while animals are consciousness
Electrocution - when system
properly used quick death
- live animals - pre stun shock
House gassing
- normally a mild culling process
- slow death
CAS - quick death
- not enough animals, birds could be consciousness in phase two.
ConclusionsConclusions
Feather spreading
Feather spreading
Advantage Disadvantage
RF2 - closed container - walking with birds out of the house
Electrocution - walking with birds and shackling
House gassing
- closed house - ventilation on and doors open after gassing
CAS - closed system
ConclusionsConclusions
Working conditionsWorking conditions
Advantage Disadvantage
RF2 - cage system: not running after birds
- catching live birds: aviary, free range and floor systems
Electrocution - cage system: not
running after birds
- catching live birds: aviary, free range and floor systems
House gassing
- dead birds: no running
- rigor mortis
CAS - cage system: not running after birds
- catching live bids: aviary, free range and floor systems
Thank you for your attention.Thank you for your attention.
Questions?