Mechanical, electrical or gas stunning; slaughter methods and monitoring signs of unconsciousness or consciousness
Mechanical stunning of food animals
- the outcome of mechanical stunning produces a pathological state of the brain incompatible with consciousness and sensibility until the animal can be bled out
- mechanical stunning requires proper targeting to achieve this outcome
- the best landmark for the targeted area is a midline frontal approach
- the projectile, when used, should be targeted towards the animal's brainstem for most consistent stunning results
- targeting the brainstem using landmarks other than midline frontal may include, for example,:
- the side of the head, behind the ear or near the poll at the top or the back of the head
- targeting the brainstem using landmarks other than midline frontal may include, for example,:
- however, alternative approaches may increase the likelihood that the brainstem and midbrain will be missed
- a projectile can sever the spinal cord without causing unconsciousness
- If a landmark other than the midline frontal is used then it will require documented evidence or validation by the licence holder to show the alternative approach can stun the animal properly:
- for example, a poll (top of the head) entry using firearms may be more useful for heavily horned sheep and all goats
Captive bolt stunning
- captive bolt stunning may be penetrative or non-penetrative
- both methods rely on the outcome of instantaneous and massive disruption of brain function to render the animal unconscious
- Cartridges with compressed air, gunpowder or a spring under tension drive the bolt either against the skull or through it
Penetrative captive bolt stunning
- the outcome causes unconsciousness from the combined effect of the concussive blow to the head and the penetrating bolt creating damage to the brain as it passes through and retracts
- the impact alone creates pressure or shock waves that have multiple effects disrupting normal brain function, including flattening of the cerebrum contralateral to the shot
- the passage and retraction of the bolt creates additional damage from a cavitation effect, hemorrhage, bone fragmentation, crushing, laceration and tearing of axons and blood vessels
- even when the targeting is not optimal, such as when the animal moves, the animal may still be correctly stunned because of the massive damage from the impact and local damage of the bolt; therefore, slightly lower or slightly higher targeting can still work as long as essential parts of the brainstem are still damaged
- however if the relevant structures are not damaged or the damage is limited, the animal may be still conscious or partially conscious and will require a second stun
- targeting too high will only reach the cerebellum
- targeting too low will only slightly damage the frontal cortex with the undesirable outcome that the animal is wounded but conscious
Non-penetrating captive bolt stunning
- the outcome relies on the mushroom head causing unconsciousness from the concussive impact of the blow alone
- rapid oscillations in the resulting pressure waves cause the resulting loss of consciousness
- there may also be concurrent fracturing of the skull from the impact and internal brain hemorrhage
- it requires extreme accuracy to be effective; therefore the landmarks are extremely important
- for this reason, it should be used only in very young and small animals such as poultry, rabbits, and ruminants weighing less than 10kg and the head should be well-restrained to help with the accuracy of the blow
- However, in immature animals, this method may crush the skull and result in an ineffective stun
Preventive Control Plan (PCP) for captive bolt equipment
- The licence holder's written animal welfare PCP for the captive bolt stunning equipment should include the following preventive measures, procedures and information:
- equipment operators are trained and competent to use the equipment and are able to monitor the signs of an effective stun for each animal
- the design, caliber, charge, bolt length, bolt tip, and bolt velocity are:
- appropriate for the type of animal, as per the manufacturer's directions and/or specifications
- effective for the licence holder's intended use
- documented in the written PCP
- there are a sufficient number of equipment so they can be rotated to prevent overheating, and can be available as a backup stunning method
- equipment is used, cleaned, and maintained, and stored as per the manufacturer's recommendations
- charge cartridges are stored in a clean dry area and have not aged excessively
- bolt velocity is checked by a velocity checker, or similar means as stated in the manufacturer's directions
- bolt(s) retract completely, as designed, after each use
- the procedure including test equipment and frequency for testing the stunning equipment
- it is never tested on a live animal
- frequency should include at a minimum at the startup of production, production shift changes, before each new lot of birds or employee shift changes
Firearm stunning
- Firearm stunning is used only when the:
- licence holder has demonstrated that no other means of stunning is practical or works as well:
- for example, for horses, firearms may give a better stun than captive bolt stunning, depending on stun pen layout, horse temperament and nature
- equipment operators are trained and competent to use the equipment and recognize the signs of an effective stun
- caliber and range are suitable for the species and class of animal
- the ammunition selected for the species and body type to be slaughtered provides effective stunning while minimizing over-penetration or the effects of misdirected bullets or ricochet
- ammunition is stored in a clean dry area and has not aged excessively
- the firearm is cleaned and maintained and stored to ensure it functions effectively
- licence holder has demonstrated that no other means of stunning is practical or works as well:
- In addition, there should be:
- a bullet proof barrier between the stunning area and the kill floor to protect people from the effects of misdirected bullets, slugs, or ricochet
- remote viewing to allow monitoring of stun efficacy and bleed-rail insensibility with protection from the effects of misdirected bullets or ricochet
- a visible warning system to indicate when firearms are being discharged
- back-up stunning equipment, readily available
- The licence holder's written PCP should include:
- written documentation that the equipment complies with the federal Firearms Act and all applicable provincial and local legislation and that firearms are well maintained as per manufacturer's recommendations
- equipment operators are trained and competent to use the equipment and are able to monitor the signs of an effective stun for each animal
- the procedure including test equipment and frequency for testing the stunning equipment
- it is never tested on a live animal
- frequency should include at a minimum at the startup of production, production shift changes, before each new lot of birds or employee shift changes
Captive bolt stunning of poultry or rabbits
- This method of stunning:
- can be used as the primary method of stunning birds or rabbits in low volume establishments because of the slower line speeds
- requires equipment appropriate for the species
- is performed by competent personnel as per the licence holder's animal welfare PCP:
- equipment operators are trained and competent to use the equipment and are able to monitor the signs of an effective stun for each animal
- the procedure including test equipment and frequency for testing the stunning equipment
- it is never tested on a live animal
- frequency should include at a minimum at the startup of production, production shift changes, before each new lot of birds or rabbits or employee shift changes
- Date modified: