To evaluate alterations in fecal bacterial compositions in weaning piglets after supplementation with Phellodendron Cortex extract (PCE), piglets were allowed freely to consume feed containing 10 ppm of PCE for 7 weeks. During the feeding period, fecal samples were collected from individual piglets. A total of 578 valid sequence reads were generated from 40 fecal samples of normal piglets before supplementation with PCE. Fifteen classes were identified. Approximately 90% of classifiable sequences belonged to Clostridia and Bacilli classes. The abundance of Clostridium spp. and Lactobacillus spp. was determined based on the results of the sequencing. The supplementation with 10 ppm PCE for 3 weeks increased the numbers of Clostridium spp. and Lactobacillus spp. whereas seven weeks of supplementation with PCE reduced their abundance. In vitro, PCE inhibited the growth of E. coli and Salmonella enteritidis in a dose-dependent manner.

Due to lack of established operating conditions, the swine manure management process circulates bio-liquor between the slurry pit and the bioreactor process cannot be effectively used yet. Therefore, a lab scale study comprising a single bio-reactor and slurry pit was conducted to investigate the optimal operating conditions. The main experiment was performed after conducting a preliminary study on the operating conditions. In the preliminary study, the volume ratio of the bioreactor to the slurry pit was fixed at 1 and hydraulic retention time (HRT) of the bioreactor was set as 5, 10 and 15 d. In the main experiment, the HRT of the bioreactor was fixed at 5 d based on preliminary results and the ratio of bioreactor to slurry pit was set at 1:3, 1:5, 1:7 and 1:10. Since, a decrease in bioreactor performance occurred when NH4-N loading rate reached 60 g/m3/d, the loading rate of NH4-N was required to be maintained below 55 g/m3/d to achieve stable operation. Although manure excretion can definitely increase the loading rate into the bioreactor as well as NH4-N concentration in the slurry pit, the NH4-N in slurry pit can be kept consistent with the circulation rate above 9.5Q (ratio to manure excretion). The optimal volume ratio of the bioreactor to the slurry pit and HRT of the bioreactor to fulfill these operating conditions was 1:3 and 5d, respectively. Notably, studying of the individual farm situation is very important to establish an ideal method to apply the optimal operation conditions suggested in this study.