Effects of dietary levels of chito-oligosaccharide on ileal digestibility of nutrients, small intestinal morphology and crypt cell proliferation in weaned pigs

There is continued need for novel agents to improve intestinal function in weaned pigs. Some evidence suggests that chito-oligosaccharide (COS) supplements may enhance pigs' intestinal function after weaning. The present study was designed to examine the effect of COS supplementation on growth performance, nutrient digestibility and small intestinal functions in weaned pigs as an effective alternative to antibiotic addition in post-weaning diets. For the experiment, weanling pigs were divided into 5 groups (13-14 animals per group) and received either a basal diet, a supplemented diet with 75, 150 or 225 mg/kg COS, or a supplemented diet with 110 mg/kg lincomycin for 56 days. Growth, feed efficiency, hematological and biochemical profiles, nutrient's ileal digestibility, small intestinal morphology and crypt cell proliferation were measured at 28 and 56 days of the experiment. Pigs supplemented with 150 mg/kg COS or lincomycin showed: (i) consistently more digestible ileal contents (e.g. crude protein, crude fat, ash, calcium, and phosphorus), (ii) increased absorption capacity (e.g. increased villus height and the villus height/crypt depth ratio for three intestinal segments) on day 28 of the experiment and (iii) more active cell division (as indicated by Ki-67 marker of duodenal and jejunal crypt cells) on day 56 of the experiment (P < 0.05, respectively). These data suggest that 150 mg/kg COS might be a useful dietary supplement to promote nutrient absorption and digestibility efficiency.