Respiratory disease in broiler chickens is a significant welfare concern driven by poor air quality, pathogen pressure, and the physiological vulnerabilities of fast-growing breeds.
Respiratory welfare in poultry is often invisible to consumers but represents a significant chronic welfare burden for millions of birds. Chronic low-level ammonia exposure causes ocular lesions, respiratory tract damage, and suppressed immune function - birds in poor air quality are simultaneously suffering respiratory discomfort and are more susceptible to infectious disease. Good ventilation that maintains ammonia below 10-15 ppm throughout the flock cycle is achievable but requires investment in house design and ongoing management attention. Welfare assurance schemes that include air quality monitoring provide a meaningful welfare benefit that pure stocking density or housing type regulations do not capture.