Adequate ventilation in pig housing is critical for respiratory health and welfare, with poor air quality causing chronic respiratory disease in millions of pigs annually.
Pig respiratory health welfare involves preventing the chronic respiratory disease burden that results from poor air quality and inadequate biosecurity. Pigs in high-ammonia environments have impaired respiratory mucosal defenses making them more susceptible to viral and bacterial pathogens that cause lung damage, fever, reduced feed intake, and growth depression over weeks to months. The welfare harm of chronic respiratory disease is real and preventable: adequate ventilation that maintains appropriate air quality reduces pathogen load and immune suppression simultaneously. The connection between ventilation welfare and antibiotic stewardship is important: reducing respiratory disease incidence through welfare investment reduces the antibiotic use that drives antimicrobial resistance.