Avian Influenza in the Netherlands 2003: comparing culling methods

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)

Colloqium Avian InfluenzaColloqium Avian Influenza

Introduction Problem definition and research questions Material and methods Results Discussion Conclusions

IntroductionIntroduction

Outbreak AI started March 2003

Culling AI-sensitive animals

HKI Wageningen B.V. offered equipment 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 is the:

- capacity

- animal welfare

- feather spreading

- working condition

of each method used during the AI outbreak in the Netherlands in 2003, defined per farming system?

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: small mobile slaughter lines with a water box

Material and methods Material and methods

- RF2: small garbage containers are filled with 60 % CO2.

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 ( nospreading 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 from one to ten. One is enormously stressfull and ten 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?