Evaluating the Effects of Pine and Miscanthus Biochar on , Total Aerobic Bacteria, and Bacterial Communities in Commercial Broiler Litter.

() is a commensal bacteria found in the gastrointestinal tract of poultry; however, some strains are pathogenic and can cause a wide range of diseases. In addition, some strains of pathogenic can survive in the litter between flocks, making litter management critical for reducing -associated infections. Biochar (BC) is a porous, carbonaceous material that may be a beneficial litter amendment to reduce moisture and microbial loads. The objectives of this study were to evaluate the effects of pine BC, miscanthus BC, and Poultry Litter Treatment (PLT) on , total aerobic bacteria populations, and bacterial communities when added to used broiler litter. Pine and miscanthus BC were mixed into poultry litter at inclusion rates of 5%, 10%, 20%, 25%, and 30% w/w. PLT was surface applied at a rate of 0.73 kg/m. Baseline and aerobics were measured after a 48-hr litter incubation period and just prior to adding litter treatments. and aerobics were enumerated 2 and 7 days after adding treatments. Overall, pine BC at 30% had the lowest and aerobic counts (5.98 and 6.44 log colony-forming units [CFU]/g, respectively); however, they were not significantly different from the control ( ≤ 0.05). At day 2, 30% pine BC inclusion rate treatment resulted in a significant reduction in and aerobic bacteria counts compared to the control. Miscanthus BC application did not result in significant reductions in or aerobic bacteria at days 2 or 7. PLT had the highest (7.07 log CFU/g) and aerobic counts (7.21 log CFU/g) overall. Bacterial community analysis revealed that the alpha and beta diversity between pine BC- and PLT-treated litter were significantly different. However, neither BC type significantly impacted bacterial diversity when compared to the control. Differences in and aerobic counts between BC types may be attributed to variations in feedstock physiochemical properties.