The Agriculture and Horticulture Development Board (AHDB) has commissioned a report on CO2 pig slaughter, as the Association of Independent Meat Suppliers (AIMS) welcomed a proposed large-scale trial of the system.
AHDB commissioned Europe Economics to estimate the plant-level costs and practical implications of converting from high-concentration CO2 to alternative systems for stunning and killing pigs in a commercial UK pig processing facility.
It was pointed out that the report reflected a “consistent view” from stakeholders that welfare must be appraised across the entire stunning pathway, from lairage and pre-stun handling through movement along the raceway and restraint up until the point of loss of consciousness, rather than focusing solely on the induction phase.
The report highlighted that while there are concerns about CO2 slaughter, alternative systems currently present their own welfare risks in commercial settings when viewed holistically. It went on to say that electrical systems typically require single-file presentation to the point of stun, increasing handling pressure and the likelihood of aversive interventions, alongside a higher risk of mis-stunning where systems are not optimally configured and managed.
AHDB said there was currently no argon-based stunning system operating anywhere in the world at sustained commercial line speeds, meaning any rapid transition would carry “significant practical uncertainty and welfare risk” without robust UK-based scientific and operational trials. It also said that implementing argon into commercial abattoirs would bring additional occupational health and safety risks for staff working around stunning systems, requiring careful assessment, infrastructure adaptation and workforce training before any deployment at scale.
A spokesperson for AHDB said: “Taken together, the sector’s view is not that change should be resisted, but that any future transition must be evidence-led, properly resourced and delivered over a realistic timeframe to ensure it results in genuine welfare gains rather than unintended setbacks.
“In practice, this would require fully funded, UK-based trials at commercial scale, alongside sufficient lead-in time for evaluation, workforce preparation, and safe implementation across the processing base.”
AIMS welcomes report but warns of potential installation challenges
Charles Milne, spokesperson for the Association of Independent Meat Suppliers (AIMS), responded: “This is a high quality and useful piece of work that flags up the challenges that moving away from a carbon dioxide approach to stunning will entail. The proposed future study on the availability and consistency of supply of Argon will also add useful information to this debate.
“Some of the challenges of installing new infrastructure for argon have been raised not least the ability to install additional stunners recognising that some plants do not have the space available to achieve this. The current rotary gas pens may not allow the very low oxygen levels required for effective argon stunning due to turbulence. Whilst some challenges for extending operating hours have been raised including availability of a suitable workforce, FSA’s ability to provide inspection teams etc there is no mention of the reduction of time available for cleaning and maintenance which would result from this approach.
“Overall, the lack of existing commercial examples of running these systems supports the suggestion that a large-scale commercial trial is required to inform both Government and industry of the practicalities of such an approach.
“Electrical stunning seems to me less suitable as a large-scale replacement due to the welfare issues associated with increased handling and the economic impact of reduced carcase quality.
“We have seen in the past, with the banning of sow stalls and tethers, that there is a real risk of exporting pig production to countries with lower welfare standards than the UK. This is simply passing the buck and is morally reprehensible. In my view if the Government wishes to unilaterally press ahead with these changes AIMS should canvas for a commercial trial, paid for by Government, to inform the change and for Government to provide reassurance that the FSA resources required to support plants through this imposed change will be available.”
