Dietary supplementation of tributyrin improved the growth, feed utilization and intestinal histology of grass carp ( Ctenopharyngodon idella )

Abstract

To investigate the effects of dietary tributyrin (TB) on grass carp (Ctenopharyngodon idella), five diets were prepared with supplementing TB at 0 (TB-0), 200 (TB-200), 400 (TB-400), 600 (TB-600) and 800 (TB-800) mg/kg and then fed to grass carp with initial body weight of 17.0 ± 0.2 g for 60 days. TB-400 and TB-600 groups presented higher weight gain, higher retention of protein, lipid, ash and lower feed conversion ratio than TB-0 group (p < .05), and TB-400 group also showed higher digestibility of dry matter and protein as well as intestinal amylase activity than TB-0 group (p < .05). Compared with the control, the serum superoxide dismutase activity was increased, and malondialdehyde content was decreased in TB-400 and TB-600 groups (p < .05), while TB-200 and TB-400 groups presented higher serum lysozyme activity than TB-0 group (p < .05). The villus height in foregut was increased in all the tributyrin-supplemented groups, but the villus height in midgut was increased only in TB-400 and T-600 groups (p < .05). The relative abundance of Erysipelatoclostridium tended to increase, and Aeromonas tended to decrease in TB-400 group. In conclusion, dietary tributyrin promoted the growth and feed utilization, enhanced serum antioxidant capacity and improved intestinal health of grass carp. Based on growth performance, the appropriate dietary supplementation of tributyrin is 443.5 mg/kg by using quadratic regression analysis.