Assessing Environmental Mitigation Strategies in Controlled Cage-Free Aviary Housing Systems: Effect on Air Quality and Bioaerosols

Abstract

Highlights Three mitigation strategies were tested in experimental chambers fitted as small-scale aviaries. Particle monitor and high-flow air samplers were used to sample airborne dust (PM) and bioaerosols. Oil emulsion sprinkling on the litter surface of aviaries was effective in reducing PM emissions in experimental chambers. Abstract. Alternative housing systems for laying hens are gradually replacing battery cages. Though these systems provide more space per animal and enrichments, higher concentrations of ammonia and airborne dust have been reported in those environments. In this project, three environmental control strategies and a control condition were tested in twelve experimental chambers fitted as small-scale aviaries. The experiment was conducted during three periods spanning 18 weeks, during which PM and bioaerosols were sampled in each chamber in three separate sampling campaigns. Emissions of PM, culturable bacteria and molds, total bacteria, Penicillium, and Aspergillus molds and selected fecal indicators (Campylobacter coli, Campylobacter jejuni, Clostridium perfringens, Escherichia coli, Enterococcus spp., Salmonella spp.) were assessed in each experimental chamber. Strategies that included oil emulsion sprinkling on litter surface were effective at reducing PM emissions, while no significant effect (p > 0.05) was observed on ammonia emissions, and the effect on bioaerosol was variable under the evaluated conditions. Keywords: Airborne dust, Aviaries, Bioaerosol, Laying hen alternative housing, Mitigation.