VPH and Abattoir Welfare Flashcards
What are the general principles of the Welfare of animals at the time of killing regulations 2015 (UK) and the EC1099/2009 on the protection of animals at the time of killing?
It is an absolute offence to cause or permit an animal avoidable excitement, pain or suffering
The loss of consciousness and sensibility shall be maintained until the death of the animal
The methods which do not result in instantaneous death/simple stunning shall be followed as quickly as possible by a procedure ensuring death such as bleeding, pithing, electrocution or prolonged exposure to anoxia
Distinguish stunning and simple stunning.
Simple stunning = recoverable (must be followed by a method to kill)
Stunning = non-recoverable, such as gas or cardiac arrest stunning
What does ‘without pain’ mean?
Without pain should mean a procedure which produces brain dysfunction before than animal can feel the procedure or any effect of the procedure
How long does it take for a painful stimuli to be recognised as painful?
100ms
How is unconsciousness achieved?
Inducing a dysfunction affecting:
- The cerebral hemispheres on a large scale
- The reticular formation
- Or the ascending reticular activating system or the median thalamus bilaterally
What is brain death?
A brain-dead animal has no clinical evidence of brain function upon physical examination . This includes no response to pain and no cranial nerve. Reflexes include pupillary response reflexes. (fixed pupils), oculocephalic reflex, corneal reflex the caloric reflex test, no response to and no spontaneous respirations
What are calorcic reflex tests?
Cold water in ear, eye movement towards that ear, warm water, away from ear
Can we measure brain death?
The EEG measures brain voltage in microvolts. All positive responses suggest brain function, cortical death occurs when the EEG is silent.
Visual evoked potential/VEP – a measure of residual consciousness that can be used to obtain objective measures of brain death
What are the signs of brain dysfunction?
- Loss of posture
- No rhythmic breathing
- No corneal reflex
- No response to pain
What are the possible stunning methods?
- Mechanical methods
- Electrical methods
- Gas methods – killing method in the UK
- Other methods – lethal injection but not used/legal as people want to eat the meat
What are the stunning methods for red meat?
Captive bolt
Controlled atmosphere
Electrical stunning
Explain the physics of captive bolt stunning.
- Energy of the bolt, accelerates the skull (but not the brain) – hit on the skull that stuns not hit on the brain
- The brain (which is floating in CSF) accelerates a fraction of a second after the skull – will keep moving to have pressure waves through the brain. Depending on how strong, can go down the brainstem and so has a gap between movement post stunning
- The concussion induces immediate potassium efflux resulting in depolarisation of the neurons
- It also causes the secretion of excitatory neurotransmitters and a calcium influx into the cells which disrupts mitochondrial function, and therefore, the production of energy
- The shock wave can push the brain tissue through the opening of the tentorium resulting in compression of the brain stem which may cause slowing/cessation of breathing and cardiac function
- Following concussion, the bolt causes local fragmentation of the skull and crushes brain tissue and blood vessels in its trajectory
- The retraction of the bolt temporarily leaves a void in the tunnel created by its passage that sucks in the surrounding brain tissue causing further tearing of axons and blood vessels
- Haemorrhage further deprives certain brain structures of the blood supply, and lack of nutrients and oxygen disturbs the inter- and intra-cellular biochemical balance
- Cranial bone fragments introduced into the brain cause further damage
How long does captive bolt take?
1.5ms
What is the problem with captive bolt stunning?
You can’t guarantee to hit the right spot every time
What is the difference between penetrating and non-penetrating captive bolts?
The potential for recovery - more likely to recover from non-penetrating as there is not the extra damage of the bolt retrieving but still work in the same way with pressure waves.
What are the factors affecting captive bolt gun performance?
- Kinetic energy = ½ x mv^2 so speed is everything
- Gun type and condition – clean well to maintain
- Choice of cartridge/air pressure
Why develop a health and welfare plan for a farm?
Helping farmers with a useful management tool to improve their herd/flock
What does goof health planning entail?
- A farmer/vet relationship focussed on improving health, welfare and performance
- Improved farm profits
- Better stock heath and welfare
- Improved sustainability
What are the 4 principles of the DEFRA farm health planning?
- Measurement – collecting data to identify the cost of health and welfare problems
- Management – prioritise control measures for problem areas, cost/benefit calculations for the most effective measures
- Monitor – regularly review farm health plan
- Seek advice
What is or should be health and welfare planning?
- Current policy/protocols
- Records
- Review
- Action plan
- Benchmarking outcomes
What does the Defra Animal Health and Welfare Strategy for Great Britain (2004) include?
- Identification of risks of introduction and spread of disease and infections
- Early recognition of disease
- Prioritising measures to control any existing problems and manage risks, including the responsible use of medicines
What are the problems with farm health planning?
- Most farms have plans but often not valued
- Records are available but often poor accuracy
- Reviewing of plan or records is very limited
- Farmers not aware of problems
What can be done if there are complex and persistent disease (and welfare) problems?
Enforce – legislation, certification
Educate – technical advice
Encourage – better communication
What is the ideal position for captive bolt in cattle?
At the intersection of 2 imaginary lines drawn from the top of the eyes to the base of the opposite horn bud