Scientists list priority research to replace high-concentration CO2 stunning of pigs


Scientists list priority research to replace high-concentration CO2 stunning of pigs

8 July 2020
Pigs display behaviour such as gasping, trying to escape and vocalising when they are stunned for slaughter using high concentration CO2.

The latest EFSA opinion on pig welfare at slaughter confirms that there is currently no way to prevent or mitigate the pain and distress caused by this type of stunning, which is common in all major EU pig abattoirs. Now a new report aims to provide guidance on the most promising alternative methods that require further research as a matter of urgency. We are pleased to see that the European Commission has provisionally shown a willingness to promote such research in the coming years. 

High concentration CO2 stunning is currently one of the more common methods to stun pigs at slaughter in Europe and is considered practical and beneficial for meat quality. But, as the latest EFSA opinion on pig slaughter just confirmed, this method is incompatible with animal welfare and should be replaced as soon as possible with painless alternatives. According to the EFSA opinion, CO2 stunning causes pigs “pain, fear and respiratory distress” and there is no way to prevent or minimise these severe animal welfare problems. 

Animal welfare NGOs have long been campaigning against this stunning method, which is unacceptable on animal welfare grounds. At the end of last year, Eurogroup for Animals and its Member Organisations called on the European Commission to revise the Slaughter Regulation to phase out the use of high-concentration CO2 as a stunning or killing method for pigs. Now a new report, commissioned by Eurogroup for Animals and Compassion in World Farming (CIWF) to scientists at the RISE Research Institutes of Sweden, recommends alternatives that could replace it.  The executive summary is available online. 

The report, entitled ‘Potential alternatives to high concentration CO2 stunning of pigs at slaughter’, discusses the various controlled atmosphere stunning and physical methods that are available to stun pigs before slaughter and highlights the most promising potential alternatives to high-concentration CO2. Based on the findings of this report, last spring the European Parliament submitted a proposal for an EU research project (preparatory action) to find painless stunning methods for pigs. We hope that this project will be carried out by the European Commission as a matter of priority.

Any widely used method to stun animals should induce instantaneous unconsciousness or, if the process is gradual, not induce pain or distress” says Reineke Hameleers, CEO of Eurogroup for Animals. “It’s urgent that resources are devoted to researching and developing alternatives that can be widely and quickly adopted.”

Encouragingly, the Farm-to-Fork Strategy includes the long-awaited revision of the Slaughter Regulation, even though CO2 stunning of pigs isn’t mentioned per se. We will continue to closely monitor this dossier and to ensure that it maintains a high level of priority.


Dr Elena Nalon, Senior Veterinary Adviser, Eurogroup for Animals