Carcass dressing Flashcards
Whats the sequence of events for beef slaughter/ processing? (start with AM inspection)
AM inspection- stunning= shackling- bleeding- head removal- hide removal- evisceration- splitting-spinal cord- trimming- marking- washing- chilling- quartering- deboning
What are the aims of stunning?
- Humane killing
- Obtain max amount of blood from animal to increase keeping quality
- Health and safety
What does a certificate of competence cover?
- Handling animals
- Stunning animals
- Pithing
- Restraining
- Shackling
- Hoisting
- Bleeding live animals
- Checking successful stun
- Check pithing worked
What are the slaughter methods?
1) Gas
2) Captive bolt
3) Electronarcosis
Which animals would you use a non pen captive bolt on?
-Simple stunning on cattle, sheep, goats and deer under 10kg
What are the physiological affects of stunning?
- Brain impact causing physical damage
- Damage to nerves/ blood vessels
- Massive rise/ 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 different phases of an effective stun?
Tonic phase: 10-20 seconds - animal collapses -stops breathing -rigid -head extended/ hing legs flexed - forelegs straighten out gradually Clonic phase: involuntary kicking Relaxation: walking/ paddling movements
When do you normally shackle an animal?
After the clonic phase of stunning due to H&S of involuntary kicking
Does an OV have to supervise scaptive bolt stunning?
Yes
-need formally trained staff and OV supervision
What are the different systems for electric stunning?
- Low voltage system: 7 secs
- High voltage: 3 secs
- Head only (reversible)
- Head to body: (cardiac arrest- irreversible)
What is the minimum current used for cattle? (head only)
+6months= 1.28Amps
young=1.25
What is the minimum current for sheep/ goats? (head only)
1A
What is the minimum current for pigs? (head only)
1.3A
What are the phases of an epileptiform fit?
- Unconscious/ insensible to pain
- Tonic: rigid, rbeathing stops, head raised, hind legs flexed
- Clonic: gradual relaxation, waling/ paddling, downward rotations of eyes, urination
- *NO TONIC PHASE= NO STUN
How long do the different phases of an epileptiform fit last in different species?
-Pigs/ goats/ sheep:
tonic= 10-20 secs, clonic= 15-45 secs, recovery= 30-60 secs
-Cattle: tonic= 5-20secs, clonic= 10-60, recovery= 45-90
-Calves: tonic=8-14, clonic= 8-28, recovery= 40-70
What are the different methods of gas stunning?
1) Carbon dioxide, high conc
2) Carbon dioxide, mixed with inert gas
3) Inert gases
How is carbon dioxide at high concentrations used to stun?
- Minimum conc 80% CO2
- Exposure to pigs must cause anoxia
- Pigs must not enter chamber is conc less than 80%
- Must be exposed to max conc of dose within 30secs of entering chamber
What is anoxia?
Loss of oxygen to the brain
How is CO2 mixed with inert gases used to stun?
Pigs must be exposed directly/ progressively to a gas mixture containing up to 40% CO2
- Max conc is 40%
- Must lead to anoxia
How are inert gases used to stun?
- Must be exposed directly/ progressively to an inert gas mixture e.g. argon or nitrogen
- Must lead to anoxia
What equipment is needed for gas stunning?
- Chamber to hold the gas
- Flusher to remove gas so staff can enter safely
- Back up mechanical device
- Able to visually check pigs in stunner
- Must be able to access pigs quickly to bleed them
- Enough space for pigs to lie down without lying on top one another
- Adequate lighting for pigs to see surroundings and other pigs
- Must not cause bruising/ compression of pigs chest.
How do you assess an effective gas stun?
- Recumbent animal with relaxed limbs and jaw tone
- No voluntary movement
- No response to pin prick on nose
- Absence of normal breathing
What are the advantages of gas stunning?
- No excitement
- Completely relaxed resulting in easy bleeding
- Intensified respiration: better bleeding
- Non invasive
- Reduced blood splash
- Reduced Pale Soft Exudate
- Pigs easier to manage as moves as a group not individuals
What are the disadvantages of gas stunning?
- Very expensive
- Welfare doubts: acidic gases pungent to inhale if more than 40%, potent respiratory stimulant (feeling of breathlessness), not instantaneous
When is bleeding normally performed?
-During tonic phase
How is bleeding performed?
- Neck cut (carotids AND jugulars)
-Thoracic stick = ascending aorta- more training needed for this method
MUST be done by person with a cert of competence
What factors affect bleeding?
- Health of animals
- Rest prior to slaughter (muscle tone)
- Back bleeding (into thoracic cavity)
- Blood splashing= capillary rupture
Which stunning is capillary rupture more common in?
Electrical
What must people look out for when dehiding?
- That the skin underneath is dry
- People must be trained to spot abnormalities and to keep carcass clean/ not contaminated
Which carcasses undergo head removal?
Sheep and cattle
What stage of processing is a grambelling table used in?
Dehairing pigs
Where are the risks of contamination when preparing the skin of pig carcasses?
The scalding tank: water can be dirty and a contamination risk
- Grambelling table impact
- Impact between carcasses on the line
- Can cause faecal matter to leak from carcass?
What is the purpose of the singing phase?
- To remove any remaining hair
- Also improves food safety
What are the benefits/ disadvantages to polishing pigs?
- Improve quality by eliminating burned hair/ superficial skin
- Excessive force can cause minor damage
- Increases contamination risk
- Expensive kit
What happens during evisceration?
- Stomach/ intestines removed
- Done with carcass hanging as gravity helps remove internal organs
- MUST be trained to ensure don’t rupture organs as this is a contamination risk
- Particular contamination of coliforms risk
What is involved in the trimming phase of processing?
-Vet must verify trimming has occurred
What is an EU health mark?
-
What is an EU health mark?
- Shows food has been produced to current standards of hygienic food production in a licensed premises.
- Allows food to be traces back to the premises
- Bottles of milk and food of animal origin in EU has this mark on it
What does third country approval involve?
- Must be checked by an OV
- Third country has to complete a quetionnaire to verify standards etc
- Have to meet EU standards
- Must complete a directorate inspection
- Draft legislation prepared
