Avian influenza outbreaks require mass culling of poultry flocks to prevent disease spread. How culling is carried out has major welfare implications for millions of birds.
The welfare of poultry during avian influenza culling operations is determined by the speed with which operations can be conducted and the method used. Where millions of birds must be killed rapidly to prevent disease spread, the pressure for speed can override welfare considerations, leading to the adoption of methods including ventilation shutdown that cause suffering before death. This is a genuine emergency welfare dilemma: the alternative of slower, more humane methods may allow disease spread that ultimately causes more total suffering through additional outbreaks. The welfare-positive approach is to invest in methods that are both fast and humane — whole-house gassing systems that allow rapid, simultaneous, unconscious death — and to reduce outbreak frequency through biosecurity and vaccination programmes.