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Lizzie comment: Time for a fresh look at pre-slaughter stunning

14th May 2024 / By Lizzie Wilson

NPA chief executive Lizzie Wilson explains why a new working group has formed to take an in-depth look at the pig stunning and slaughtering process.

Lizzie Wilson 22The stunning and slaughtering process is an extremely important and sensitive subject, and, therefore, can often also be quite contentious.

Unfortunately, the outcome is that much of the commentary has become driven by emotion, rather than logic at a time when we should be focused on evidence, animal welfare and practical viability.

More importantly, the narrative fails to recognise the slaughter of animals is quite rightly one of the most regulated (by government), observed (by vets and trained staff) and closely monitored (by CCTV) practices in industry.

Despite this, we acknowledge concerns expressed by citizen groups and welfare campaigners that slaughter could and should be more humane. It goes without saying that there are also areas where the process could be improved – science moves on, as do technologies and opportunities to share information and collaborate.

That is why I’m very pleased that key players across the UK pig sector have teamed up to form a new working group to look at pre-slaughter stunning of pigs. This expert group will revisit current methods and try to fast-track a review of new ways to make the end-of-life process as painless and stress-free as possible.

The group includes veterinary surgeons, scientists, academic researchers and technical specialists from the country’s leading pig producers and supply chain, levy board AHDB, the NPA and assurance body Red Tractor, the Humane Slaughter Association, as well as colleagues from Europe and Australia. By working in a coordinated way, the aim is to take a responsible and global approach.

As a reminder, the law which underpins the Welfare of Animals at the Time of Killing (England) Regulations 2015, sets out the legal standards by which pigs can be stunned before slaughter. These include passage of electrical current through the brain, controlled atmosphere exposure to high concentrations of carbon dioxide (CO2), or by penetrating captive bolt.

A particular focus of the new group will be a review of controlled atmosphere exposure to high concentrations of CO2. This method offers some benefits compared with others, for example the pigs remain in groups which can be less stressful from a handling perspective than stunning them individually. The process is also largely automated, reducing human handling and risk of error.

However, CO2 can be strongly aversive to pigs – although this is minimised by ensuring loss of consciousness within 15 seconds. The fact that pigs display physical signs of activity during the time up to loss of consciousness, but also show reflex movements after they have lost consciousness, further complicates assessments of the practice.

There are alternatives, and some that have been investigated include use of inert gases, electrical stunning, low atmospheric pressure stunning and nitrogen foam. While research programmes globally are investigating these new methods, none are yet at the stage where they can be commercially adopted.

Further development will depend on government approval, financial investment, and the willingness and capability of designers, engineering companies and available equipment.

Watch this space.