This study investigated the effect of processing methods of Cassava (Manihot esculenta Crantz) root on Growth Performance, Feed Utilization, Survival Rate and Body Composition of Nile tilapia, (Oreochromis niloticus) under hapa in concrete pond system. Cassava roots were processed using six different methods and finally, nutrient content was evaluated using standard methods of Association of Official Analytical Chemists (AOAC). To evaluate the effects of different processing methods on growth performance of fish, five hundred and twenty five (525) Nile tilapia (Oreochromis niloticus) fingerlings with an average initial body weight of 8.34± 0.05g were collected from Hawassa Agricultural Research Center Fish Breeding Station. The fish were stocked in 21 (6m2 each) experimental hapas (Cloth hatchery) each with 25 fingerlings randomly distributed in triplicate. The fish stocked in the 21 hapas were fed with Control diet and six Experimental diets and reared for 120 days. The results revealed that the highest values of growth performance: mean weight gain (WG) 54.6±6.7 g, daily growth rate (DGR) 0.45±0.06 g and specific growth rate (SGR) 1.66±0.09 %/fish/day were observed on the fish fed with SBYFSDCBD (soaked, boiled, yeast fermented and sundried Cassava based diet). Similarly, the best feed conversion ratio (FCR) 2.03±0.68 and protein efficiency ratio (PER) 1.67±0.2 were recorded in diet SBYFSDCBD. It is concluded, that the dietary inclusions of SBYFSD and SBRFSD Cassava root in fish diet increased the growth performance, feed utilization and body composition of the Nile tilapia without any negative effects, and thus, it is a future promising feed ingredient for Nile tilapia feed production. Finally, more detailed studies are required to investigate information on digestibility and levels of anti-nutritional substances of the test feed, Cassava root.

Keywords: Cassava processing, Cassava root, growth performance, Nile tilapia, nutrient content