Editor’s note: In addition to publishing its regular news coverage of broiler welfare issues and the movement toward slower-growing broilers, WATT Global Media will be publishing a special series on these topics. This is the fifth installment of the series.

Controlled atmosphere stunning (CAS) is being pitched as a more humane alternative to electrical stunning of chickens and turkeys prior to slaughter, but is that truly the case?

That is a question for which the poultry industry is still seeking to find a definitive answer.

Purchase pledges favor controlled atmosphere stunning

When foodservice and restaurant companies started making broiler welfare policies in late 2016 that called for specific conditions with which they must comply, most called for birds to be rendered unconscious by CAS or low-atmosphere stunning methods.

Among the foodservice companies that were early to commit were Aramark, Sodexo, Delaware North, Centerplate and AVI Food Systems. Restaurant chains early to make CAS pledges included Pret A Manger, Panera Bread, Starbucks, Le Pain Quotidien, Chipotle and Shake Shack.

All of those commitments were made prior to February 2017 and since that time, many other companies have followed suit.

How methods are administered more important than which methods

According to experts in the industry, the method used, whether controlled atmosphere or electrical, is not necessarily what is the most important from an animal welfare perspective. Instead, the most important factor is how the methods are administered.

That view is shared by Dr. Yvonne Vizzier Thaxton, director, Center for Food Animal Wellbeing, University of Arkansas, on the National Chicken Council (NCC) website.

“The main animal welfare issue with poultry slaughter is the ability to induce instantaneous insensibility. The requirement is that all animals be insentient when slaughtered. Both electrical stunning and CAS fulfill this requirement when properly administered,” she stated.

Neither method presently preferred by experts

The NCC website also cites the World Organisation for Animal Health (OIE), the American Association of Avian Pathologists (AAAP) and the American College of Poultry Veterinarians (ACPV). None of the entities has recommended one method of stunning over another.

“Based on current research and evidence available from North American slaughter facilities, it is the position of the AAAP and ACPV that low voltage and CAS are humane and acceptable methods for stunning of poultry,” the two groups jointly stated.

Will one method eventually emerge as more humane?

Dr. Karen Christensen, extension poultry specialist and associate professor at the University of Arkansas Center for Excellence for Poultry Science, agrees with those organizations on the NCC’s Chicken Check In website in terms of there being insufficient evidence to position one method over another from a welfare perspective.

“I am not sure we know enough about these systems to declare that one is more humane than the other,” she said. “This is an important area that deserves – and is getting – a lot of attention and research. Processors want to make sure that if they need to make changes, they make the correct one for the welfare of the birds and meat quality for the consumers.”

With all that research being done, we have to wonder what will be known by 2024, the year that all of the aforementioned restaurants and foodservice companies intend to have their broiler welfare policies in place.

If the industry learns that CAS systems are indeed more humane, it would make sense that all broiler companies that are presently not using them make the switch. If research shows electrical stunning methods are better for the animal, further conversations with those companies that believe CAS is better will be necessary for the sake of the animals.