Dietary Fishmeal Substitution by Peanut-Based Meals in Nile Tilapia (Oreochromis Niloticus L.) : Effect of Pond Water Quality on Biomass Production Effect of Pond Water Quality on Biomass Production

Abstract

Abstract. A 16 week experiment was conducted in earthen ponds in Iganga District of Eastern
Uganda to investigate the effect of water quality on biomass production in Nile tilapia (Oreochromis
niloticus L.) fed on peanut-based meals as alternative dietary fishmeal. Iso-nitrogenous diets
containing 30% and 25% Crude Protein were applied for the first 12 weeks and last four weeks while
the control was a local diet for Nile tilapia of 25% Crude Protein throughout the experiment.
Treatments included the fishmeal-based diet and two peanut-based diets; peanut meal-based diet and
mixed meal-based diet. Each of the 16 pond units measuring 3.0 x 4.0 x 1.0 were stocked with 48
fish fingerlings of 21.7 grams mean weight. Significant differences (p≤0.05) in mean values occurred
among targeted parameters; pH, Dissolved Oxygen, nitrite nitrogen and unionized ammonia with
exception to temperature. Apart from the unionized ammonia, the significant variations (p≤0.05) in
water quality parameters did not significantly affect (p≥0.05) biomass production because they were
maintained in suitable ranges for Nile tilapia.