Chitosan Supplementation may Improve the Digestive Physiology and Health of Captive Leiothrix lutea

We investigated the effects of supplemental chitosan on digestibility of feed nutrients, intestinal histology and digestive enzyme activity in the pancreas, duodenum and jejunoileum in Leiothrix lutea. Sixty-four adult birds were randomly allotted to one of four dietary treatments (basal diet supplemented with 0%, 0.1%, 0.5% and 1% chitosan). The experiment lasted for 30 days, of which the last 4 days involved metabolic experiments. Compared with the control group, the addition of 0.5% chitosan enhanced the apparent metabolism rate of dry matter, metabolisable energy, crude fat and phosphorus, and decreased apparent metabolism rate of calcium; crude protein was unaffected. Compared with the control group, the villous height of the duodenum and ileum supplemented with 0.5% chitosan increased by 12.11% and 15.03%, while the crypt depth in the duodenum deepened by 6.48%. Supplemental chitosan decreased lipase and amylase activities; trypsin and chymotrypsin activities increased first and then decreased as the level of chitosan increased. These data suggest that dietary chitosan (0.5%) may improve the digestive physiology of L. lutea in captivity by increasing the apparent metabolic rate of most nutrients, improving intestinal health and enhancing digestive enzyme activity.