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

Abstract

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 to nonvolatile ammonium. Research on the effects of acid amendments on litter microbiota is limited and 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 (the 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 (NaHSO 4 )-based amendment. We used DNA sequencing technologies to characterize the litter microbiota, elucidating microbial shifts in litter samples with respect to downtime, litter depth, and NaHSO 4 application. During downtime (∼18 d), 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 Escherichia coli decreased by 1.5 log units during downtime, but an increase was observed for topdressed litter after NaHSO 4 was applied. Although the effect of acidifiers on ammonia reduction, bird performance, and litter performance are well documented, their effect on litter bacteria is not well understood. Our results suggest that acidifiers may perturb litter bacteria when topdressed with fresh pine shavings and that further research is required.

Temporal dynamics of the cecal and litter microbiome of chickens raised in two separate broiler houses

“…Litter moisture was determined gravimetrically while litter pH was determined using a Thermo-Scientific Orion probe (ThermoFisher Scientific) as described before (Johnson et al, 2021). Broiler house ammonia levels were monitored by attaching ammonia dosimeter tubes (Gastec Corporation) to metal chains hung at about 37 cm ± 5.4 cm from the litter floor of three pens from each house (Johnson et al, 2021). Readings on ammonia tubes were recorded ~7.5 h after installation and performed once a week.…”

“…Litter samples were collected from floor pens on days 7, 14, 21, 28, 35 and 42 (Figure 1). Litter was collected as grab samples from Frontiers in Physiology frontiersin.org seven locations in each pen, including the corners and under the waterers (Johnson et al, 2021). On each sampling day, litter was collected from six odd-or even-numbered pens per house (Johnson et al, 2021) (n = 72).…”

“…Litter was collected as grab samples from Frontiers in Physiology frontiersin.org seven locations in each pen, including the corners and under the waterers (Johnson et al, 2021). On each sampling day, litter was collected from six odd-or even-numbered pens per house (Johnson et al, 2021) (n = 72). Litter samples were mixed thoroughly by hand in the Whirl Pak bags and processed as described previously (Johnson et al, 2021).…”

“…On each sampling day, litter was collected from six odd-or even-numbered pens per house (Johnson et al, 2021) (n = 72). Litter samples were mixed thoroughly by hand in the Whirl Pak bags and processed as described previously (Johnson et al, 2021). Briefly, 10 g of litter were placed in a Nalgene bottle containing acid-washed glass beads covering the bottom of bottle (S800242, ThermoFisher Scientific), and 50 mL of 1 × phosphate-buffered saline (ThermoFisher Scientific) was added.…”

“…Briefly, 10 g of litter were placed in a Nalgene bottle containing acid-washed glass beads covering the bottom of bottle (S800242, ThermoFisher Scientific), and 50 mL of 1 × phosphate-buffered saline (ThermoFisher Scientific) was added. Sample bottles were mixed on an automatic wrist shaker (Boekel Scientific) at 450 rpm for 10 min and allowed to rest upright for 5 min after shaking (Johnson et al, 2021)…”