22 Apr 2025
A major European project has called for alternatives to be considered, although a UK industry group has reacted cautiously.
Allister Webb
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Researchers have demanded an urgent shift towards alternative methods of stunning pigs for slaughter after leaders of a major European project argued “significant” advances are possible.
A UK Government minister has also acknowledged a “pressing need” to review the use of high concentration carbon dioxide on welfare grounds.
But an industry group has urged the sector to seek a collective way forward, arguing a lack of clarity exists about how best to proceed.
The issue returned to prominence after leaders of the European Commission-funded PigStun project outlined its results at a meeting in Brussels on 4 April.
Although the project found pigs exposed to inert gases such as argon and helium tended to remain conscious for longer, they were also significantly less aversive than CO2, while improved electrical stunning was thought to be better for the environment overall, despite concerns over the potential for pain.
Marien Gerritzen, senior animal welfare scientist at Wageningen University and Research in the Netherlands, said CO2 alternatives “pose the opportunity to significantly increase animal welfare”, despite acknowledged concerns about potential cost increases.
He added: “We think that slaughterhouses should consider the possibility of changing to one of them.”
The comments came after academics argued argon represented a more humane option than CO2, despite itself being considered “not acceptable” on ethical or welfare grounds, in a paper published in the Frontiers of Veterinary Science journal.
One of its authors, veterinary professor Andrew Knight, said: “Current abattoir gassing systems using CO2 should be modified without delay to systems that use argon gas. We owe it to the many millions of pigs who are slaughtered for food each year.”
The issue is also currently under review by the Animal Welfare Committee, which advises Defra and the devolved Scottish and Welsh administrations.
In a joint submission, the Pig Veterinary Society and BVA said they backed the committee’s general principles on gas stunning, and argued there would need to be “strong evidence of improved welfare outcomes” if alternatives were proposed.
Veterinary professionals are also part of an industry working group, whose members include the AHDB and National Pig Association (NPA), which is conducting its own review.
An NPA spokesperson said the group was “committed to exploring alternatives and finding a solution that can deliver on animal welfare”.
But she argued there was no clearly preferable method, because of capacity, meat quality and cost issues.
She added: “The UK pig industry must now work together to decide how we go forward.”
Farming minister Daniel Zeichner also acknowledged what he called “practical constraints” that had prevented wider commercial use of inert gas stunning thus far, in response to written questions tabled ahead of the Brussels meeting.
But he added: “We accept that there is a pressing need to address the welfare concerns associated with high concentration carbon dioxide stunning of pigs and look forward to receiving the Animal Welfare Committee’s report.”
He also confirmed officials were monitoring the PigStun project’s progress, while a spokesperson later said they “look forward” to seeing its full findings.
