The objective of this study was to evaluate the digestibility of phosphorus in isonitrogenous and isocaloric diets containing 28% crude protein and 3000kcal DE/kg at different levels of total phosphorus, 0.8% and 1.2%, in Nile tilapia juveniles (Oreochromis niloticus). The water quality parameters presented significant differences (P<0.5) for total phosphorus, orthophosphate, BOD5 and conductivity. The digestibility of diets was 75.3% for fish fed 0.8% total phosphorus and 77.5% for treatment with 1.2% total phosphorus. It was observed that the efficiency rate in phosphorus absorption among the treatments was 74.3 and 76.3% for tilapia fed 0.8% and 1.2% phosphorus, respectively. It can be concluded that a percentage increase of 0.4% phosphorus in tilapia diets contributes to the increase of 55% of phosphorus in water and the lower phosphorus input in the diet can be a nutritional strategy to be practiced. Thus, it will help to reduce the impact caused by effluents from fish farming, without lowering the efficiency of tilapia diet utilization.
sustainable aquaculture; carrying capacity; phosphorus; Oreochromis niloticus; nutrient management
