Farm Animal Welfare

Poultry Controlled Atmosphere Stunning Welfare

Controlled atmosphere stunning using CO2 or low-oxygen mixtures is an alternative to electrical water bath stunning with distinct welfare implications.

Key Facts

Water bath electrical stunning leaves birds conscious if they miss the stunner
CAS using high-CO2 mixtures causes aversion and distress before loss of consciousness
Low-oxygen CAS causes unconsciousness without the aversive experience of CO2
RSPCA Freedom Foods and some retailers now require or prefer low-oxygen CAS
Transitioning from water bath to CAS requires significant capital investment

Welfare Considerations

The choice of stunning method significantly affects poultry welfare at slaughter. While water bath stunning carries risks of failed stunning, high-CO2 CAS causes detectable aversion. Low-oxygen CAS has the best welfare profile but highest cost.

What You Can Do

Support retailers and brands requiring low-oxygen controlled atmosphere stunning
Advocate for phased elimination of high-CO2 poultry stunning on welfare grounds
Ask poultry producers about their stunning method and welfare monitoring at slaughter