In this study, villus length and villus length/crypt depth in jejunum
were increased, villus width and crypt depth were reduced in both
COS and chlortetracycline groups, which indicates diets supplemented
with COS or chlortetracycline improved intestinalmucosalmorphology.
Thus, the digestion and absorption of nutrients in the jejunum were
correspondingly increased and the utilization of nutrients was improved
in piglets. This may be a contributing factor for chitosan to promote
growth performance. In previous studieswith broiler chickens fed
diets supplementedwith 0.6 g/kg chitosan, an increase in the duodenal
cell mitosis number and ileal villus area was observed [21].