Effects of Dietary Fructooligosaccharide on Digestive Enzyme Activities, Intestinal Microflora and Morphology of Growing Pigs

One hundred and twenty-eight growing barrows (Jiaxing Black${\times}$Duroc${\times}$Landrace) at an average BW of 20.8 kg were allocated to four treatments for 42 days, each of which was replicated four times with eight pigs per replicate and used to investigate the effects of fructooligosaccharide (FOS) on digestive enzyme activities, intestinal microflora and morphology of growing pigs. The pigs received the same basal corn-soybean meal diet and FOS was added to the basal diet at 0, 2, 4, 6 g/kg diet at the expense of corn, respectively. As compared to control, supplementation with 4 and 6 g/kg FOS significantly improved average daily gain and feed efficiency. Addition of FOS enhanced the growth of Bifidobacterium and Lactobacillus, but inhibited Clostridium and Escherichia coli in the small intestinal and proximal colonic contents. Supplementation with 4 and 6 g/kg FOS significantly improved the activities of total protease, trypsin and amylase in the small intestinal contents. However, FOS had no significant effect on the activity of lipase in the small intestinal contents as well as the digestive enzymes in pancreas. Morphological measurement of jejunal mucosa did show response to consumption of FOS. Villus height and the villus height to crypt depth ratio at the jejunal mucosa were significantly higher with 4 and 6 g/kg FOS supplementation as compared to control.