Effects of dietary polysaccharides from the submerged fermentation concentrate of Hericium caput-medusae (Bull.:Fr.) Pers. on performance, gut microflora, and cholesterol metabolism in broiler chickens

The present study was conducted to investigate the effects of polysaccharides from the submerged fermentation concentrate of Hericium caput-medusae (Bull.:Fr.) Pers. (HFCP) on growth performance, gut microflora, and cholesterol metabolism in broiler chickens. A total of 480 one-day-old Arbor Acres male broilers were randomly assigned to 4 treatment groups with 6 pens per treatment and 20 broilers per pen. Diets containing 4 concentrations of HFCP (0, 1, 3, and 5 g/kg) were fed to the broiler chickens. The experimental diets were fed in 2 phases, starter period (d 0 to 21) and finisher period (d 21 to 42). The results indicated that the average daily gain and the average daily feed intake increased (P<0.01) both linearly and quadratically when the HFCP levels increased. However, there was no difference in feed conversion observed among different treatment groups in each period. The serum total cholesterol, triglyceride, and low-density lipoprotein cholesterol levels decreased (P<0.001) linearly and quadratically, while the high-density lipoprotein cholesterol level increased (linear and quadratic, P<0.001) with increasing dietary HFCP levels. The caecum Escherichia coli count and pH decreased (P<0.001) linearly and quadratically, while the caecum lactobacilli count, bifidobacteria count, and propionic acid concentration increased (linear and quadratic, P<0.01) as the HFCP levels increased. On d 21 and 42, the cholesterol content in liver, thigh, and breast muscle decreased (P<0.01) linearly and quadratically, while the bile acid excretion increased (linear and quadratic, P<0.001) with increasing dietary HFCP levels. Different doses of HFCP supplementation in broiler diets had no effect on cholesterol content in excreta. In conclusion, dietary supplementation with HFCP may lead to the production of low-cholesterol broiler meat demanded by health conscious consumers, and its effect might be due to the increase in bacterial count and short chain fatty acids production in the large intestine, and the accelerated rate of catabolism of cholesterol to bile acids by HFCP.