Succession patterns of the bacterial community in poultry litter after bird removal and sodium bisulfate application.

Sulfate based acid amendments are used for treating litter between broiler chicken flocks and during grow-out for in-house ammonia abatement. These amendments reduce litter pH and inhibit ammonia volatilization by converting ammonia into nonvolatile ammonium. Research on the effects of acid amendments on litter microbiota is limited and are usually done in microcosms, which do not replicate natural environments. In this study, we determined the changes in bacterial populations present in litter during downtime (period after a flock was removed and before new broiler chicks were placed) and 24 h before and after the application of a sodium bisulfate (NaHSO4 ) based amendment. We made use of DNA sequencing technologies to characterize the litter microbiota, elucidating microbial shifts in litter samples with respect to downtime, litter depth, and sodium bisulfate application. During downtime (∼18 days), the litter microbiota was dominated by Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria. Sodium bisulfate affected the microbiota in the top layer (3 cm) of reused litter topdressed with fresh pine shavings and resulted in an increase in Escherichia spp. and Faecalibacterium spp., and a decrease in members of the phylum Acidobacteria. Furthermore, culturable E. coli decreased by 1.5 log units during downtime, but an increase was observed for topdressed litter after sodium bisulfate was applied. While the effect of acidifiers on ammonia reduction, bird performance and litter performance are well documented, its effect on litter bacteria is not well understood. Our results suggest that acidifiers may perturb litter bacteria when topdressed with fresh pine shavings and requires further research. This article is protected by copyright. All rights reserved.