Processed cassava root tuber as maize replacers in the practical diet of Nile tilapia, <i>Oreochromis Niloticus</i>

Abstract

The study investigated the effects of differently processed cassava root meal on the growth performance, nutrient digestibility, and liver pathology in the diets of Oreochromis niloticus. Cassava tubers (IITA-TMS-I982132) were conditioned to four different processing techniques namely: sun-drying (SDC), soaking (SC), solid-state fermentation (SSF), and anaerobic fermentation (AFC). Five isonitrogenous (35% crude protein) diets were formulated in which maize was replaced at 50% level by each of the processed cassava root meals. Diet 1 (CTR), Diet 2 (SDC50), Diet 3 (SSF 50), Diet 4 (SC 50), and Diet 5 (AFC 50) were fed to 120 fingerlings (3.20±0.50g) ad libitum in three replicates. At the end of a 90-day rearing period, feed conversion ratio (FCR) was significantly different (p<0.05) among treatments and lowest (1.49±0.20) in fish fed Diet AFC but highest (1.61±0.02) in SC. Percentage weight gain (PWG) (286.82±3.77%), protein efficiency ratio (PER) (1.94±0.24), and protein digestibility (81.85±1.50%) were significantly (p<0.05) better in fish fed AFC than other treatments. There was no visible distortion of the hepatocytes of the liver implying that the treatments did not affect the liver tissues. The study concluded that O. niloticus could be successfully cultured on diets containing 50% aerobically fermented cassava tuber.