The efficacy of oolitic aragonite for ammonia control and microbial modulation in broiler litter

Ammonia released from broiler litter remains a longstanding challenge for poultry producers, with implications for bird health, worker comfort, and impacts on surrounding environments. This study investigated the suitability of oolitic aragonite, a naturally occurring ooid sand, as a broiler litter amendment to improve litter conditions and potentially limit ammonia production. Given its mineral composition and unique particle morphology, oolitic aragonite may have potential applications for influencing moisture dynamics, nutrient interactions, and microbial community development within litter. Despite initial hypotheses that oolitic aragonite would regulate ammonia volatilization through reducing water activity and promoting nitrifying/denitrifying pathways, no significant differences were observed between treated litter and the control litter in ammonia emissions, total nitrogen, uric acid, or water activity. The ammonia flux rose during flock cycles and peaked after windrow composting across all treatments. Microbial community analysis of start and end samples from each flock showed alpha and beta diversity were driven mainly by temporal succession, with shifts from gut-associated to litter-adapted genera. While differential abundance testing found few consistent treatment effects, Lysobacter , a genus associated with antimicrobial activity, was persistently enriched in OA treated litter. Observed effects on microbial diversity were subtle and did not result in meaningful functional shifts in the broader community composition between treatments. While ooliotic aragonite as a standalone amendment did not significantly affect ammonia emissions, its selective enrichment of Lysobacter warrants further investigation.