Strategies for Improving Air Quality in Next-generation Livestock Buildings Integrating Animal Welfare Considerations

ARACELI DALILA LARIOS MARTÍNEZ, Valérie Létourneau, Vicki Clouet-Côté, Inès D Dhib, Caroline Duchaine, Sébastien Fournel, Alexis Ruiz-González, Magali-Wen St-Germain, Laurianne Gratton, Andrea Katherin Carranza Diaz, Mahsa Baghdadi, Stéphane Godbout, Agri-Food Engineering Division, Research and Development Ins

     Abstract Number: 486
     Working Group: Bioaerosols in Agriculture: Sources, Risks and Mitigation

Abstract
The transition from conventional to next-generation livestock buildings, incorporating considerations for animal welfare, has been occurring over recent years. While next-generation facilities offer increased freedom of movement for animals, they may potentially exacerbate air quality issues due to increased animal activity, larger areas for excretion, and increased nutritional requirements. Exposure to emissions such as ammonia (NH3), particulate matter (PM), and bioaerosols has been linked to both animal and human health concerns, including infections and non-infectious diseases such as reduced lung function, asthma, chronic bronchitis, and hypersensitivity pneumonitis. Factors influencing NH3, PM and bioaerosol emissions include litter and manure management, environmental conditions, ventilation rate, as well as animal mobility within the facilities. To assess the impact of transition to these new production systems, concentrations of NH3, PM, and bioaerosols, as well as environmental conditions and ventilation rates, were measured in both conventional and next-generation livestock buildings across various housing systems. They included cage and cage-free laying hen housing, caged and group housing systems for gestating sows, and tie-stall and free-stall housing for dairy cows. Subsequently, literature reviews were conducted to identify and compare available mitigation strategies aimed at improving air quality in livestock buildings. Following this, discussions were held with expert panels to select the most relevant strategies for implementation in next-generation facilities. Selected strategies were then tested in commercial barns. For example, in a commercial aviary housing 20,000 birds per floor, the efficacy of sprinkling a water-oil acid emulsion on litter surfaces was evaluated. Similarly, at a gestating sow barn with 405 sows housed in separate gestation group pens, the impact of varying slurry removal frequencies and room temperature adjustments was examined. Additionally, in a commercial free-stall dairy barn housing 93 dairy cows, the effectiveness of sprinkling a bedding additive (biolitter) is currently under evaluation. To assess the efficacy of these mitigation strategies, concentrations of NH3, PM, and bioaerosols were measured before and during the trial period, alongside monitoring of temperature, humidity, and airflow rates. This paper aims to present the results and the overall impact of these efforts on improving air quality in next-generation livestock buildings.