Utilization of Nuisance Aquatic Plant (Duckweed) in Partial Replacement of Soybean Meal in Feeding Clarias gariepinus (Burchell, 1822) Fingerlings.

Abstract

Duckweed (Lemna gibba), a nuisance aquatic macrophyte, was studied as a substitute for the partially replacement ofsoya bean meal in the diet of Clarias gariepinus fingerlings. Four dry diets formulated at 4% crude protein were fed to fingerlings at 0% (control) 10%, 20% and 30% inclusion levels of duckweed meal named as Diet A, B, C and D respectively. The fish were feed at 5% body weight and was assessed for feed conversion ratio (FCR), protein efficiency ratio (PER), survival rate among others. The highest growth performance and nutrient utilization was recorded at diet D i.e. 30% inclusion rate of duckweed with a mean weight gain of 5.45 + 0.309g, and food conversion ratioof 3.32 + 0.43 which was significantly different (P < 0.05) to the values obtained for other diets. The lowest weight gain was recorded in diet A i.e. the control diet, with a value of 3.06 + 0.03g. The result of this study showed that as the inclusion rate of duckweed is increased, there was a corresponding increase in the growth rate of the fish. The study demonstrated that duckweed can be used for the replacement of soya beans in the diet of catfish fingerlings, thus converting a nuisance weed into useful feed component for the reduction of feeding cost.