Air Quality and Livestock Welfare in Housed Systems

Air quality in livestock buildings — including ammonia, dust, carbon dioxide, and humidity — profoundly affects respiratory health, welfare, and productivity across all housed species.

Key Facts

Ammonia above 10 ppm causes measurable respiratory irritation in pigs; EU limits are 20 ppm
Dust in poultry buildings reaches concentrations that cause respiratory disease and eye inflammation
Hydrogen sulphide from slurry in badly ventilated pig buildings can be acutely toxic
Natural ventilation systems with good design often outperform mechanical ventilation for air quality

Welfare Considerations

Air quality welfare operates through both acute and chronic pathways. Acute exposures to high ammonia or hydrogen sulphide cause immediate respiratory distress and eye inflammation. Chronic low-level exposure to ammonia and dust causes progressive respiratory damage that compromises immune function and increases susceptibility to infectious disease. Air quality is also a welfare indicator that reflects the cumulative effect of management decisions including stocking density, bedding type, ventilation system, and waste management. Buildings with poor air quality consistently show worse welfare outcomes across health, behaviour, and production metrics.

What You Can Do

Support air quality standards and monitoring requirements in livestock building regulations
Advocate for ventilation design requirements that ensure adequate air quality throughout buildings
Choose products from farms with documented air quality management protocols
Support research into cost-effective ventilation improvements for existing livestock buildings