Abattoirs and Humane Slaughter Flashcards
What is stunning?
Performed to render the animal unconscious and insensible to pain prior to slaughter. Slaughter can then be carried out painlessly (and safely for the workers).
How are animals slaughtered in Australia after stunning?
Occurs after stunning. Blood vessels carrying oxygenated blood to the brain are severed (“sticking”). The result is death from lack of oxygen to the brain (cerebral anoxia).
What is head only electrical stunning?
(two types of electrical stunning- head only and cardiac) With head only, electrodes placed on either side of the head result in passage of an electrical wave. A minimum of 1.25 amps must be passed through a pig’s brain to reliably induce insensibility
(Can be used for halal)
3 Phases and signs of effective stun (head only electrical stun)
* Tonic- no rhythmic breathing, animal collapses and becomes rigid, head is raised, forelegs extended and hind legs flexed
* Clonic- relaxation of muscles, padding or involuntary kicking, downward movement of eyeballs, urination and defecation
* Recovery- resumption of normal rhythmic breathing, response to painful stimuli, becomes visually aware, attempts to stand
What is the most effective method of bleeding?
Cattle- chest stick
Sheep & goats- chest stick OR carotid artery cut (permanent insensibility in around 10 seconds) (do not have a well developed vertebral artery)
What is non penetrative captive bolt?
A mushroom head captive bolt rapidly accelerates and decelerates the brain in the cranial cavity with the effect of causing massive stimulation and firing of neurones and thus insensibility. Often associated with this is general sub-dural haemorrhage.
* Commonly used in adult cattle (but can be used for sheep, goat, pigs)
* “sticking” must occur quickly after to avoid return to sensibility
*generally acceptable for halal
What are some signs of an effective stun using captive bolt?
What kind of livestock is CO2 stunning commonly used for? Explain.
Pigs
* groups of pigs enter a chamber that is then filled with 80% to 90% CO2 in air (minimum 60% CO2). Pigs lose consciousness within 30 seconds.
* can be some struggling or excitement before loss of consciousness
* A variation is the controlled atmosphere chamber used for poultry (mixture of CO2, nitrogen, argon)
What is head-to-back electrical stunning?
* This stun will result in an epileptiform seizure and secondly fibrillation of the heart. This causes loss of heart functionality, generally blood stasis and reduced oxygen supply to the brain.
* Generally used in small livestock (sheep and pigs) can be used in cattle.
What is penetrative captive bolt stunning?
Bolt should pass between two cerebral hemispheresand hit the region above the hypocampus resulting in massive electrical disruption of all areas of the brain. The hypocampus is the point of crossover for the nerve fibres of both hemispheres before the nerves exit the brainstem.
* Also results in a percussive wave within the brain tissue increasing the disruption to normal nervous impulses
* used in cattle, goats, and sheep
* Same signs of an effective stun as non-penetrative
What is sticking?
Severing the blood vessels to prevent blood supply or oxygenated blood supply to the brain
aka Slaughter
Chest stick or cut across the throat
What period do you have with sheep from stun to stick while the animal is insensible?
35 seconds
Why don’t you sever carotid artery only in cattle? What about pigs?
There would be a period where the animal was bleeding out and sensible after stunning. Therefore you sever the blood vessels near the heart, the brachiocephalic a.
** arteries are cut in the chest, like in cattle
What is offal?
internal organs or entrails, meat of butchered animals
What are the valuable parts of an animal?
How is animal welfare related to food quality and food safety?
What is the problem with bruised meat?
How do you avoid bruised meat?
What is the problem with blood splash/ ecchymosis?
How do you prevent blood splash/ spotting?
What is dark cutting beef? What is the problem with it?
* after death, muscle glycogen is broken down (anaerobic glycolysis) producing lactic acid which lowers pH of the meat
* Poor nutrition (on-farm) will reduce muscle glycogen stores
* stressed animals (before or during transport or at the abattoir) will deplete muscle glycogen prior to slaughter
* less glycogen at slaughter= less lactic acid= higher pH
What is the pH where beef starts to darken? When it is dark? Ideal pH?
How do farmers prevent dark cutting beef?
* train and educate cattle so they can be handled easily
* select for cattle with good temperment
* keep the time from mustering to slaughter as short as possible
* avoid selling stock during extreme weather or seasonal conditions e.g. hot, humid, cold, wet
* do not mix social groups during transport or at abattoir
* Do not present sick or injured stock for slaughter
What is Pale, soft, exudative pork?
Pigs
How do you avoid PSE pork?
Abattoir design and food safety considerations
What are the ante-mortem inspection objectives?
Post mortem inspection- objectives?
To make sure carcasse is free of disease
Aim of chilling
