Abstract: In order to understand the effects of soybean oligosaccharide (SBOS) on the intestinal microbial community structure in Cherry Valley ducks, T-RFLP method was adopted to study the amounts of Escherichia coli, Bifidobacterium, and Lactobacillus in the duck caecum under effects of different concentration SBOS.
 Applying SBOS decreased the amount of E. coli in caecum. Compared with that of the control, the amount of E. coli in the 3rd and 4th week after applying 300 and 500 mg·kg^-1 of SBOS and in the 3rd weed after applying 700 mg·kg^-1 of SBOS had a significant decrease (P<0.05). Applying SBOS promoted the proliferation of Bifidobacterium and Lactobacillus, being significantly (P<0.05) in the 3rd and 4th weeks after applying 500 mg·kg^-1 of SBOS. No significant differences were observed between applying SBOS and aureomycin in the effect of regulating microbial community structure in duck intestine. Our results indicated that SBOS could effectively regulate the microbial community structure in Cherry Valley duck intestine, the effect was time- and dose-dependent, and the optimal additive dose was 500 mg·kg^-1.

Key words: Chlorella vulgaris, Effective microorganism, Mudflat, Ecological structure, Water quality