Effects of lactitol and tributyrin on growth performance, small intestinal morphology and enzyme activity in weaned pigs

One hundred and sixty crossbred pigs (6.62 +/- 0.36 kg) weaned at day 18 +/- 1 were used to investigate the effects of lactitol and tributyrin on performance, small intestinal morphology and enzyme activity. The pigs were assigned to one of five dietary groups (4 pens/diet with 8 pigs/pen) and were fed the negative control diet or the negative control diet supplemented with 10 g/kg glutamine (as a positive control), or 3 g/kg lactitol (beta-D-galactopyranosyl-(1 -> 4)-D-sorbitol), or 5 g/kg tributyrin (butanoic acid 1,2,3-propanetriyl ester), or 3 g/kg lactitol+5 g/kg tributyrin. Body weight and feed intake were measured weekly during the 4-week study. On day 7, four pigs per dietary treatment were sacrificed to examine small intestinal morphology and enzyme activity. The results showed that: (1) Compared with the negative control diet, the positive control diet improved weight gain and feed efficiency during weeks 1-2 and over the entire study (p < 0.05), and also decreased duodenal and ileal crypt depth (p < 0.05), but did not alter intestinal enzyme activity (p > 0.05). Lactitol improved feed efficiency during weeks 3-4 and over the entire study (p < 0.05), but did not improve weight gain and feed intake, intestinal morphology or enzyme activity (p > 0.05). Tributyrin improved weight gain and reduced feed/gain during weeks 3-4 and over the entire study. Tributyrin significantly decreased crypt depth in the duodenum and ileum, and increased duodenal lactase and ileal maltase activity (p < 0.05). Lactitol+tributyrin increased weight gain during weeks 3-4 and over the entire study, and improved feed efficiency during weeks 1-2 and 3-4 and over the entire study (p < 0.05). Lactitol+tributyrin increased the jejunal villus height, and decreased the duodenal and ileal crypt depth (p < 0.05). Lactitol+tributyrin also increased jejunal lactase and sucrase activity (p < 0.05). (2) Compared with the positive control, tributyrin improved weight gain and reduced feed/gain during weeks 3-4 (p < 0.05), decreased the ileal crypt depth, and improved the duodenal lactase and sucrase activity (p < 0.05). Lactitol+ tributyrin improved weight gain during weeks 3-4, improved feed efficiency during weeks 3-4 and over the entire study, increased the ileal villus height, and increased jejunal lactase, sucrase and maltase activity (p < 0.05). These results showed that tributyrin improved performance, intestinal morphology and enzyme activity, while the effect of lactitol was very limited. These results also showed that, compared with glutamine, tributyrin was more effective in improving intestinal morphology and enzyme activity, and tributyrin exerted a superior effect in improving performance as weaning progressed. These observations suggest that, as a chemical for repairing intestinal atrophy, glutamine and tributyrin should be used in the first and second periods of the starter phase, respectively.