4 Flashcards
Cervical dislocation for poultry slaughter description?
Manual or mechanical stretching and twist of neck provoking cerebral ischaemia.
Conditions of use of cervical dislocation?
Poultry up to 5kg (mechanically) and 3kg (manually) live weight.
Slaughter, depopulation and other situations.
Legislation regarding cervical dislocation and percussive blow to the head.
These methods shall not be used as routine methods but only where there are no other methods available for stunning.
These methods shall not be used in slaughterhouses except as a back-up method for stunning.
What does neck dislocation actually do?
Severs spinal cord.
May produce haemorrhaging of major blood vessels.
Kill the bird through haemorrhagic shock.
Unlikely to concuss bird.
Not immediate kill.
- ~100 seconds for brain death to occur.
– conscious for quite a lot of this.
How long after cutting off a chicken’s head does the brain die?
~130 seconds.
Captive bolt for poultry.
Acceleration of the head sufficient to produce a stun.
Possible tissue damage prevents recovery.
Resultant flapping means brain destroyed.
- do not flap as much as with neck dislocation as pressure wave goes down spine.
How is electrical stunning achieved in poultry?
By passing an electrical current through the brain by either direct application to the head (head-only) or passage of current through the whole bird using a water-bath stunner.
- head only causes a lot of flapping and damage to pectoral muscles and wings.
- Minimum current for chicken head-only stunning?
- Minimum current for turkey head-only stunning?
- 240 mA.
- 400 mA.
- Minimum current for waterbath stunning of chickens?
2, Minimum current for waterbath stunning of turkeys?
- 100 mA.
- 250 mA.
Problems w/ head-only poultry stunning?
Inversion of the bird.
- no diaphragm so crush thoracic organs.
Speed of application.
- slow – not feasible commercially.
Post stun flapping (enhance spinal reflexes).
- reduced carcase quality.
Types of waterbath stunners?
Stun-to-stun (high frequency).
- chickens and turkeys.
- simple stunning.
Stun-to-kill (low frequency - 50Hz producing cardiac fibrillation)
- hardly used as produces carcass damage due to direct muscle stimulation at 50Hz in 20 ms.
- ducks and geese – red meat.
– do not contract with as much force so not as much damage.
- stunning.
Recommendations for phasing out waterbath stunners for poultry.
Not included in regulations because impact assessment revealed such recommendations were not economically viable at present in EU.
Important to continue discussion in future.
To this end, the Commission should prepare and submit to the European Parliament and the Council a report on the various stunning methods for poultry, and in particular multiple-bird waterbath stunners.
Issues w/ poultry waterbath stunners?
Bird inversion is stressful.
Shackling is painful.
Pre-stun shocks are painful.
Variation in current received.
Difficult (impossible?) to assess stunned state in commercial setting.
Conflict between welfare and carcass quality.
By law, what is the maximum amount of time a bird can be hung upside down while conscious?
- what about for ducks, geese and turkeys.
1 minute.
- 2 minutes.
What should be in place for point of shackling to point of stunning to calm birds down?
A system in contact w/ the breast of the birds.
- the bottom of the breast comforter should be below the head of the largest bird to reduce visual field by half.
How do pre-stun shocks occur?
When part of the bird (other than the head) touches the live water.
If you invert a bird, generally the wings hang lower than the head.
From a non-welfare viewpoint, what is the issue w/ pre-stun shocks?
Increased damage to the breast muscle so a reduce carcase quality.
Variation in current received.
Resistance of the birds vary.
Higher resistance causes lower current received.
Currents lower than 100 mA means the bird is not stunned.
To ensure every bird is adequately stunned, need to apply more voltage and so lower resistance birds receive an excess of current and muscle contractions are very forceful so carcase quality is greatly reduced due to damage caused from this.
- this causes loss of product so is typically not done so welfare is compromised.
