Why is a controlled atmosphere system replacing the electrical stunning poultry slaughter method?

Slaughter is the first phase of poultry processing and debatably the most challenging and complex. It involves killing living animals and ensuring they are effectively fed into a system without getting themselves stressed or the staff dealing with them. Poultry slaughter practices have consequences for meat quality, effectiveness, and an invisible element: our relations as humans with the creatures we utilize for meat. Therefore, an alternative poultry slaughter practice is getting great attention in the United States of America. Almost every industrial level poultry slaughter equipment stuns poultry birds to begin their slaughter. This is because nearly every poultry slaughter equipment manufacturer has designed that equipment to kill them by stunning them. Electrical stunning, generally through a water bath, is the standard poultry slaughtering practice in the United States of America due to its speedy throughput and comparatively low cost, both operational and capital.

Humane gas

A primary alternate stunning system does not use electricity at all. Instead, it makes the poultry birds sleep through the controlled utilization of gas. In a poultry slaughterhouse, butchers carry out the controlled atmosphere system by exposing poultry birds to carbon dioxide, usually increasing degrees of it in stages to limit oxygen accessible to them. Then, the poultry birds become unconscious but not lifeless, which is an optimal condition to bleed out. This process could either be stun-kill or stun-only, depending on the gas levels to which the poultry birds are exposed and the duration of time for which the poultry birds endure in gases. The largest advantage of this controlled atmosphere system is that contrary, unlike electric power shock, it slowly brings about unconsciousness. This eradicates the chances of damaging the meat and is considered more humane. That is why it is popular in Europe, where animal welfare rules are more rigorous.

Other advantages of using controlled atmosphere systems

The employment of controlled atmosphere systems to kill poultry birds has risen in popularity across the globe in recent times. In 2013, a survey reported that slaughterhouses employed the controlled atmosphere system to slaughter seventy-one percent of poultry birds across the United Kingdom. The utilization of controlled atmosphere systems varies throughout the European Union. Still, it has been estimated that slaughterhouses now slaughter one-fifth of broiler chickens, seven percent of laying hens, and twenty-four percent of turkeys in the European union by utilizing the controlled atmosphere systems. Slaughterhouses are now replacing electrical water bath stunning methods with controlled atmosphere systems and are generally viewed as a more humanistic alternate.

Compared to electrical water bath stunning, one main welfare benefit of using controlled atmosphere systems is the elimination of the manual handling of birds. In many cases, the bird transportation containers could be directly loaded into a controlled atmosphere system without the need to remove the poultry birds first. In addition, some controlled atmosphere systems utilize well-suited mechanical catching equipment, which entirely eradicates the need for any pre-slaughter poultry bird handling from the bird rearing barn to the time when birds are slaughtered. Inside electrical water bath systems, poultry slaughterhouse workers need to manually remove the poultry birds from their transport crates separately and hang and invert them by their legs on a metal chain, which carries them to the water bath.

There are also other main welfare advantages of utilizing controlled atmosphere systems. For instance, in comparison to electrical water baths, they could offer a more reliable and consistent introduction to unconsciousness

and in the United Kingdom, it is a law that requires killing poultry birds in the poultry slaughter system instead of being only stunned.

Gases

There are different controlled atmosphere systems’ benefits available across the globe, which have been developed to be utilized with various gases or gas mixtures, some utilize carbon dioxide gases while some utilize inert gases like argon, and others utilize a mix of these two gases- carbon dioxide and inert gases. Further, many systems have been developed to kill the poultry birds by exposing them to one or more steps or stages, whereby every step or stage consists of different levels of gas being utilized, beginning at a low level of concentration and growing to a greater level of concentration. These systems kill birds or irreversibly stun them as the gases being utilized do not consist of oxygen.