The coalition is concerned that a new slaughter method being considered in the US, which uses a vacuum to stun animals before slaughter, has not been fully investigated and urges the poultry industry to only use methods approved by the country's top animal welfare scientists.
A coalition of concerned animal welfare organisations, which includes Compassion in World Farming, has written to more than 30 of the United States' largest chicken processors urging them not to implement a little-tested slaughter method for poultry.
Employing "vacuum stunning" or "low-atmospheric pressure killing" (LAPK), the relatively new process involves a rapid reduction in air pressure leading to loss of consciousness and death. However, there is insufficient evidence to know this slaughter method is humane.
Evidence in support scant
Advocates suggest the process is more humane than industry standard methods of stunning, but as the coalition writes in the letter "…the evidence to-date does not offer meaningful data to support claims that LAPK is humane, nor does it answer many critical questions about the birds' experience from an animal welfare perspective. Because of the numerous critical unanswered questions regarding the impact of vacuum stunning, we cannot encourage a commercial switch to it at this time."
Welfare experts concerned
Several leading animal welfare scientists, including world-renowned expert Dr. Temple Grandin, have expressed concerns that LAPK might cause chickens to experience significant pain.
Dr. Mohan Raj, visiting fellow in the University of Bristol's School of Veterinary Sciences believes that there is a risk conscious birds subjected to LAPK will endure ruptured intestines and air sacs. Dr. Raj argues that gases produced in the gut may not escape passively, in which case:
"…expansion of gases trapped in the gut will cause painful rupture. This may lead to internal contamination of carcasses with faeces, which is [also] a public health and food safety issue," he said.
Grandin and other leading animal welfare experts recommend "controlled-atmosphere killing" (CAK) as the least painful slaughter method available. In CAK, the chickens are placed in a gas mixture, rather than a vacuum, in which they lose consciousness and die. Animal welfare scientists believe that this is more humane than other methods of large-scale commercial slaughter.
Compassion advocates CAK in preference to LAPK or electrical stunning, which involves shackling conscious birds prior to stunning.
More information on the welfare issues affecting meat or broiler chickens is available here.