Effects of Supplementation of Insoluble Dietary Fiber Obtained from Cinnamon Spent Bark Waste on the Performance of Nile Tilapia (Oreochromis niloticus) Fingerlings

Dietary fiber supplementation has proven benefits on fish health and growth. Cinnamon spent bark waste is the cinnamon bark residue after oil distillation. It is a rich source of insoluble dietary fiber with very low contents of soluble dietary fiber. This study aimed to investigate the potential of using water-extracted insoluble fiber from cinnamon spent bark waste as a functional ingredient in the diets of Oreochromis niloticus fingerlings. Four experimental diets were prepared by replacing a commercial feed with extracted dietary fiber at 0 (control), 0.5%, 1%, and 1.5% levels. Fingerlings of O. niloticus were assigned to the four experimental diets and the feeding trial was conducted for 12 weeks. The results revealed that the weight gain, specific growth rate, feed conversion ratio, Fulton’s condition factor, and survival rate of fish were not significantly different among the experimental groups. Fiber supplementation at 1.5% significantly increased (p<0.05) the total aerobic bacteria population in feces, whereas the coliform counts in feces at 0.5% and 1% fiber supplementation were significantly lower (p<0.05) than the control. There was a significant increase (p<0.05) in red blood cells count at 0.5% fiber supplementation. Moreover, insoluble dietary fiber supplementation significantly (p<0.05) increased the white blood cell counts in blood. Results suggested that insoluble fiber supplementation affected gut microbial populations and blood parameters of O. niloticus fingerlings. However, further investigations on gut microbiology and hematology are needed to ensure the use of insoluble dietary fiber from cinnamon spent bark waste as a functional ingredient in the diets of O. niloticus fingerlings.