Biosecurity measures prevent the introduction and spread of infectious diseases in livestock, directly protecting animal welfare by reducing illness, suffering, and emergency culling. Good biosecurity and good welfare are complementary goals.
Infectious diseases cause substantial animal suffering independent of any control measures. Respiratory disease, enteric infections, and systemic illnesses cause pain, distress, and often death. Emergency control measures including culling may themselves cause welfare harms if not conducted with appropriate methods and speed. Preventive biosecurity that keeps disease out of a herd or flock is therefore not only economically important but represents a meaningful welfare improvement for animals who never experience disease.