Abstract: This study was aimed to investigate the effects of fermented Siraitia grosvenorii residue on the intestinal morphology and flora of yellow-feathered broilers. 360 one day old healthy yellow-feathered broilers were randomly divided into 4 groups with 6 replicates in each group and 15 broilers per replicate; Broilersin the control Group (Ⅰ)were fed a basal diet, and the others in (Ⅱ,Ⅲ,Ⅳ) group, 1-21 days old were fed with 1%, 3% and 5% fermented siraitia pomace in the basic diet to replace corn; 22-42 days and 43-70 days old were fed with 5%, 8% and 10% fermented siraitia pomace, respectively. The trial period was 70 days. The results showed that compared with the control Group I, the age of 21 days and 42 days,there were no significant difference between Group in the villus height, recess depth and V/C of duodenum, jejunum and ileum in Ⅰ, Ⅲ and Ⅳ. At 70 days of age, the duodenal recess depth of Group III and Group Ⅳ decreased by 36.01% (P<0.05) and 33.46% (P<0.05), the V/C increased by 78.05% (P<0.05) and 69.98% (P<0.05), respectively. In terms of intestinal flora, the number of OTUs shared by Group I and Group Ⅲ were 537, and the number of unique OTUs in Group I and Group Ⅲ were 55 and 7 respectively; At the phyla level, the core microflora are Firmicutes, Bacteroides and Proteus, among which, the relative abundance of Proteus and Epsilon bacteraeotain Group Ⅲ were significantly lower than that in Group I (P<0.05); At the genus level, the uncultured_bacterium_f_Clostridialgroup in Group III was significantly higher than that of trial Group I (P<0.05); Alpha diversity index and Beta diversity index of Group I and Group III were not significantly different (P>0.05). Fermented Siraitia grosvenorii residue could ameliorate intestinal micro environment and health of Yellow-Feathered Broilers.

Key words: Siraitia grosvenorii, fermented feed, broilers chickens, intestinal morphology, species diversity