User:Brian Tomasik/sandbox/CAK

Controlled atmosphere killing (CAK) is a slaughter method used in poultry farming in some European Union countries. The technique removes oxygen from the birds’ atmosphere, replacing it with argon, nitrogen, or carbon dioxide, asphyxiant gases that slowly and painlessly neutralize consciousness relatively early in the slaughtering process. Similarly, slaughterhouses may use controlled atmosphere stunning (CAS), which merely renders the birds unconscious in their transport containers until they are manually executed by farmers.

Motivations

CAK is estimated to have several benefits over electric immobilization. It simultaneously improves animal welfare, worker safety and satisfaction, meat quality, efficiency of meat production, and reduces the negative environmental impact of slaughterhouses.

Advantages of CAK:

• Improved animal welfare

Animals are executed earlier in the slaughtering process, making them unable to experience several highly unpleasant stages of factory farming including shackling, throat-cutting, bleeding, and scalding. In a system using electric immobilization, chickens and turkeys endure high levels of stress and pain, as they are sent down crowded conveyor belts, shackled by their legs and hung upside down, shocked painfully during electric baths, sometimes have their throats slit while conscious, and sometimes scalded to death in boiling water.

Electric immobilization is intended to stun birds into a state in which they are insensible to the pain of throat slitting and (if the killing machine fails) scalding. The conventional method employed by North American slaughterhouses, however, uses an electrical current strong enough to paralyze birds but not strong enough to render them insensible to pain.

Typically, birds are killed by an automatic spinning blade, commonly referred to as the "killing machine," and then defeathered in tanks of scalding hot water. But birds are sometimes able to evade the killing machine's blades, in which case they are still alive when landing in the scalding water tanks. The number of birds that die by scalding can reach as high as 3% during plants with inadequate supervision . In unusual situations, this number can be much higher .

In CAK systems, birds are dead long before the defeathering process, eliminating risk of death by scalding.

• Improved worker safety

1. Slaughterhouses are dimly lit, crowded, noisy, disease ridden places.
2. Live animals, especially full-grown turkeys, can hurt workers in their struggle to survive. Dead animals are much easier for workers to deal with because they do not struggle.
3. Workers risk injury from their own knives.
4. Workers must wear breathing protection due to the dust in the air caused by the stressed wing flapping of live birds.
5. Birds can vomit or defecate on workers.
6. Poor worker morale and high worker turnover.

In CAK systems, lighting is kept bright, the air is clearer, and workers do not bare the stress of handling struggling birds. The job is both physically and psychologically less demanding.

• Environmental advantages

1. Less waste
2. Less water is required to rinse off carcasses
3. Increased yield --> More storage in conditions less likely to lead to spillage

• Economic advantages

Improved quality and yield:

1. Less blood spots on meat,
2. reduced bruising,
3. fewer broken bones,
4. less hemorrhaging,
5. improved shelf life (reduced rate of discolouration and bad odours),
6. reduced contamination,
7. does not impede bleedout, residual blood in the carcass is low,
8. better muscle fiber structure at the cellular level

Higher meat yield means implementation costs can be made back quickly.

Reduced labour, refrigeration, and energy costs:

1. faster pH fall in carcasses -->
2. faster maturation rate -->
3. early filleting -->
4. less refrigeration time -->
5. less refrigeration and energy costs

Disadvantages of CAK:

• Implementation costs

These costs can be fully recovered after a year to a year and a half.