The effects of dietary chitosan or glucosamine HCl on liver lipid concentrations and fat deposition in broiler chickens

Dietary chitosan, a polymer of glucosamine, decrease the absorption of dietary fat and then reduce the abdominal fat deposition in broiler chickens. Chitosan is also digested and absorbed in the form of glucosamine by hens and broilers. Thus, in broiler chickens, dietary chitosan may decrease lipogenesis and triglyceride (TG) synthesis in the liver in addition to decrease fat absorption, consequently resulting in a reduction of body fat deposition. However, little research has been done to determine whether dietary glucosamine decreases hepatic TG synthesis and body fat deposition in broiler chickens. The present experiment was conducted to determine the effects of dietary chitosan or glucosamine HCl on fat absorption, hepatic TG contents and body fat deposition in broiler chickens. Broiler chickens at 14 d old were fed on a control diet based on corn and soybean meal or diets containing 5% chitosan or glucosamine HCl for 3 weeks. Dietary chitosan and glucosamine HCl did not affect feed intake, body weight gain, feed efficiency and breast muscle weight. Dietary chitosan significantly (P0.05) decreased fat digestibility, the contents of total lipid and triglyceride in the liver and abdominal fat weight. The concentration of plasma very low density lipoproteins (VLDL) tended to decrease in broilers fed on the chitosan diet. Dietary glucosamine HCl significantly (P0.05) reduced hepatic total lipid and triglyceride contents, plasma VLDL concentration and abdominal fat deposition with no influence on fat digestibility. These results suggest that dietary chitosan may decrease the body fat deposition by reducing intestinal fat absorption and hepatic TG synthesis and dietary glucosamine may decrease the body fat deposition by reducing hepatic TG synthesis in broiler chickens.