The physiology of chronic stress in intensively farmed animals and its cascading effects on health, immune function, and welfare.
The physiology of chronic stress connects animal welfare directly to animal health through the immune system. This connection has practical and regulatory implications: poor welfare does not merely cause behavioral suffering but measurably compromises the biological systems that protect animals from disease. This means that every welfare improvement — reduced density, better social conditions, environmental complexity — is simultaneously a health improvement that reduces disease vulnerability, antibiotic dependency, and treatment costs. The economic case for welfare investment in intensive farming is strongest when the full system costs of poor welfare — including disease treatment, growth suppression, and mortality — are included in the cost-benefit calculation.