Digestibilidade do fósforo em dietas como estratégia nutricional para redução de efluentes da tilapicultura

Abstract

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.