C, N, AND P BALANCES OF FIVE FEED INGREDIENTS EVALUATED AS FISHMEAL ALTERNATIVES IN TILAPIA DIETS

摘要

In recirculation system design the tank volumes, flows and dimensions of purification installations are depending on waste loads, such as C02, TAN, and phosphorous (P) originating from the fish. For the design of low discharge aquaculture systems, which are using "environmental friendly" feeds, mass balances for nitrogen (N), P and carbon (C) are of high importance. If fishmeal is replaced by another feed ingredient, the N, P and C levels and in the feed, their retention in the fish and the fish waste productions change. C, N, and P mass balances illustrate those changes. The study objective was to determine the mass balances for C, N, and P for five feed ingredients, which can be used as fishmeal alternatives in tilapia diets.