Slaughter and Carcass Dressing Flashcards
Describe the process of cattle slaughter
Describe the process of lamb slaughter
Describe the process of pork slaughter
What is the regulation regarding the protection of animals at the time of killing?
Council Regulation (EC) No 1099/2009
What is the definition of stunning?
Any intentionally induced process which causes loss of consciousness and sensibility without pain, including any process resulting in instantaneous death
What are the aims of stunning?
Kill/Slaughter humanely
Obtain the maximum amount of blood from the animal (increases keeping quality)
Health and safety
What do all members of staff working in an abattoir require?
Certificate of Competence (CoC)
What are the methods of stunning used in abattoirs and which animals are they used on
Captive bolt - ruminants (simple stun)
Electronarcosis - pigs, sheep and poultry (stun to kill in cows)
Gas - pigs and poultry (stun to kill)
What are the physiological effects of captive bolts
Heavy blow => acceleration of head => brain impact (physical damage)
Damage to nerves and blood vessels
Massive rise and fall in pressure
Disruption of normal electrical activity
Duration depends on severity of damage
What are the signs of an effective stun?
Collapse
No rhythmic breathing
fixed glazed expression
no corneal reflex
relaxed jaw
tongue hanging out
What are the phases of captive bolt stunning?
Tonic phase (10-20s)
- collapse
- stops breathing
- becomes rigid
- head extends/hind legs flexed
- forelegs straighten
Clonic phase
- involuntary kicking
Relaxation
- walking/paddling
What are the minimum currents required to electrically stun animals?
What are the phases of electrical stunning?
Induces an epileptic fit
Tonic phase:
- rigid
- breathing stops
- head raises
- hind legs flexed
Clonic phase:
- gradual relaxation
- paddling
- downward rotation of eyes
- foaming/urination
Recovery
When should sticking/bleeding be done after stunning?
before clonic phase ends (no more than 15s)
What are the different methods of gas stunning?
CO2 at high conc
CO2 + inert gases
Inert gases
Describe the process of gassing to stun via high CO2 conc
Minimum 80% CO2 conc
Exposure must lead to anoxia (loss of oxygen to brain)
Pig must be conveyed to max conc of gas withing 30s
Describe the use of CO2 mixed with inert gases for stunning
40% CO2 conc mixed with inert gases
What inert gases are used for stunning pigs?
argon or nitrogen
What are the signs of effective stunning by gas?
Recumbent animal - limbs, jaw relaxed
No voluntary movements or righting reflexes
No response to pin prick on nose
Absence of normal breathing
What are the advantages of gas stunning
No excitement
Completely relaxed => easy bleeding
Non-invasive
Reduced blood splash
Reduced pale soft exudative (PSE) => higher meat quality
What are the disadvantages of gas stunning?
Expensive
Welfare doubts:
- acidic gas pungent to inhale
- potent respiratory stimulant => breathlessness
- not instantaneous
What are methods of bleeding post stunning and which animals are they used on?
Neck cut (carotids and jugulars) = small ruminants
Thoracic stick (ascending aorta) = cattle and pigs
What are the factors affecting bleeding?
health of animals
Rest prior to slaughter (muscle tone)
Back bleeding into thoracic cavity
Blood splashing (capillary rupture)
Describe the features of blood splashing (capillary rupture)
Related to increase in blood pressure
More common in electrical stunning
Stress, diet, physiological or genetic factors
Shows as black spots on offal
What is the purpose of polishing pig carcasses?
improves quality
eliminates burned hair and superficial epidermis
What are the disadvantages of polishing pig carcasses?
Excessive force could produce some minor damage in carcass
Increases contamination
What are the official controls for exports of Products of Animal Origin (POAOs)
All POAOs exported from UK must be accompanied by an official EHC (export health certificate) signed by a vet
Documents are checked
Notifiable disease clearance
Physical checks of product
