Department of Physics, Chemistry and Biology (IFM)

I did my thesis as a follow-up study on a project that aims to improve pig welfare at slaughter.

Annually over 2 billion pigs are slaughtered for meat on a global scale. Sadly, two of the most common stunning methods used to render pigs unconscious prior to slaughter have severe drawbacks regarding animal welfare. These two methods are electrical stunning and carbon dioxide stunning.

Pigs experience less stress if they can be stunned in groups rather than one by one, and if minimal handling is necessary. These preferences can be met with gas stunning, but the commonly used carbon dioxide is painful and aversive for the pigs to inhale.

My supervisors recently studied the effect of stunning pigs in nitrogen-filled foam. Nitrogen is not an aversive gas to inhale, in contast to carbon dioxide. The nitrogen gas was capsulated in foam for efficiency in the depletion of oxygen.

Find out more about nitrogen-filled foam by visiting the homepage of Anoxia - the company that created this method for the purpose of humane euthanasia on farm.

Previous studies on pigs' behavioural responses to air-filled and nitrogen-filled foam exposure indicate that pigs show mild aversive reactions to the foam-stunning situation. The natural next step was to see if companionship could attenuate the stress from foam-exposure. Is foam-stunning a better alternative than current methods for stunning pigs - from the animal welfare perspective?