Critical analysis of the PigStun Project

To evaluate whether alternative stunning methods from the EU PigStun project are scientifically robust, practical and commercially viable for Australian pork processing compared to current CO2 stunning systems.

A comprehensive review by Australian Pork Limited, the University of Melbourne and SunPork assessed alternative stunning approaches trialled in the EU PigStun project.  
While gases such as argon and helium reduced some aversive responses during induction, they require long exposure times, reduce processing throughput, and produce less consistent meat quality.

Argon, the most promising alternative, still requires low oxygen conditions and long cycle times, while helium is not commercially viable due to the cost and supply limitations. Improved electrical stunning systems showed some welfare benefits but continued to involve stressful handling and inconsistent outcomes.

Overall, the review confirmed that high concentration CO2 stunning remains the only method that reliably meets welfare, operational, meat quality and commercial requirements under Australian conditions.  
 

Value for producers:
The findings provide strong evidence that existing Co2 stunning systems remain the most practical and commercially viable option for Australian processors. This gives producers and processors confidence that current systems continue to deliver reliable animal welfare outcomes, efficient processing speeds, and acceptable meat quality without requiring major infrastructure changes.
 

Key Findings:
 

• Alternative gases can reduce some aversive behaviours but do not match the reliability or efficiency of Co2 systems.
• Argon is the most promising alternative but requires long exposure times, reducing throughput and requiring major plant redesign.
• Argon also resulted in inconsistent meat quality, including higher drip loss and increased risk of PSE.
• Helium is not commercially viable due to high cost, limited supply, and infrastructure requirements.
• Improved electrical stunning reduced some welfare risks but still involved stressful handling and poorer meat quality outcomes than CO₂. 

Overall, the review confirmed that high concentration CO2 stunning remains the only method that reliably meets welfare, operational, meat quality and commercial requirements under Australian conditions.  

For further information, please contact APL's Research and Innovation Program Manager - Integrity and Product Quality, Dr Vaibhav Gole via email: Vaibhav.Gole@australianpork.com.au