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 (NaHSO₄)-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 NaHSO₄ 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 NaHSO₄ 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.

中文翻译：

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去除鸟类和施用硫酸氢钠后家禽垫料中细菌群落的演替模式

基于硫酸盐的酸改良剂用于处理肉鸡群之间的垫料以及用于室内氨气减排的养成期间。这些改良剂通过将氨转化为非挥发性铵来降低垫料 pH 值并抑制氨挥发。关于酸修正剂对垫料微生物群影响的研究是有限的，并且通常在不能复制自然环境的微观世界中进行。在这项研究中，我们确定了停产期间（移除鸡群后和放置新肉鸡之前的这段时间）和使用硫酸氢钠 (NaHSO ₄ ) 前后 24 小时垫料中细菌种群的变化) 为基础的修正。我们使用 DNA 测序技术来表征垫料微生物群，阐明垫料样品中微生物在停机时间、垫料深度和 NaHSO ₄应用方面的变化。在停机期间（~18 天），垫料微生物群主要由放线菌、拟杆菌、厚壁菌门和变形菌门主导。硫酸氢钠影响了用新鲜松木屑覆盖的再利用垫料的顶层（3 厘米）的微生物群，并导致埃希氏菌属的增加。和粪杆菌属。以及酸杆菌门成员的减少。此外，可培养的大肠杆菌在停机期间减少了 1.5 log 单位，但在 NaHSO ₄后观察到的追肥垃圾增加被应用。尽管酸化剂对氨减少、家禽性能和垫料性能的影响已得到充分证明，但它们对垫料细菌的影响尚不清楚。我们的结果表明，酸化剂在用新鲜松木屑覆盖时可能会扰乱垫料细菌，需要进一步研究。