Good biosecurity prevents disease outbreaks that cause mass suffering in farm animals. Understanding the link between biosecurity practices and welfare helps farmers and policymakers make better decisions.
Disease outbreaks in livestock cause enormous welfare harm both from the disease itself and from the mass culling response. Foot-and-mouth disease causes painful blisters on feet and mouths; avian influenza causes severe respiratory distress and rapid death. Preventive culling — killing healthy animals in buffer zones — causes welfare harm to prevent potentially greater suffering from disease spread. The welfare case for biosecurity is clear: preventing disease entry is immeasurably better than managing an outbreak for the welfare of the animals involved.