Growth Performance and Nutrient Utilization of Nile Tilapia (Oreochromis niloticus) Fed Processed Duckweed (Lemna paucicostata) Meal as Protein Source

Growth performance and nutrient utilization of Nile tilapia (Oreochromis niloticus) fed processed duckweed (Lemna paucicostata) meal were evaluated. Blanching and sun-drying were employed as the processing methods. The blanched and sun-dried duckweed meals were used to replace toasted soybean meal in the diets of Nile tilapia at 25%, 50%, 75%, and 100% each. Nine iso-proteinous diets were formulated using the least cost feed formulation software. The feeding trials were conducted in 27 Hapa nets measuring 1m2 each for 24 weeks. Ten fingerlings of Nile tilapia were stocked per Hapa and fed three times daily at 5% biomass. The fish fed 75% blanched duckweed meal had the best mean weight gain (460.59g), feed conversion ratio (1.82) and protein efficiency ratio (12.67) while the fish fed 100% inclusion level of sun-dried duckweed meal and 100% of blanched duckweed meal diet had the poor mean weight gain, feed conversion ratio and protein efficiency ratio of 401.69g and 394.03g, 2.06 and 2.10, 11.05 and 10.37, respectively. This study revealed that blanched duckweed meal can replace toasted soybean meal in the diet of Nile tilapia at 75% without any unpropitious effect on the growth performance and nutrient utilization.