Avaliação econômica da alimentação de tilápias em tanques-rede com níveis de proteína e energia digestíveis

Abstract

We evaluated the economic responses of Nile tilapia in the final stage (450 to 800 g) fed diets containing five levels of digestible protein (DP): 20, 23, 26, 29 and 32% and two digestible energy levels (DE): 3,000 and 3,300 kcal kg-1 based on the sale of whole animals or fillet. This experiment was carried out into 50 m3 net cages in an aquaculture area located in Paranapanema River, Palmital - São Paulo State, Brazil, from November 21st, 2010 to January 21st. Economic performance indicators were: gross revenue, partial production cost, net revenue, leveling point, balance point, benefit cost ratio and cost of feed kg-1 gain. Twenty-nine percent of DP and 3,000 kcal DE kg-1 diet provided better economic performance for sale of whole fish, meaning higher net revenue (R$ 23.09 net cage-1) and benefit cost ratio (1.08), besides the lowest balance point (R$ 3.91 kg-1). Thirty-two percent of DP and 3,000 kcal DE kg-1 diet provided the lowest cost of feed kg-1 (R$ 2.53), leveling point (17.35 kg net cage-1) and balance point (R$ 13.63 kg-1), besides the highest benefit cost ratio (1.54) when the fish were sold in fillet form. Diets with 29% and diet with 32% digestible protein, both of them with 3,000 kcal of digestible energy kg-1 diet provides better economic responses in Nile tilapia reared in net cages (450 to 800 g), to be sold, respectively, whole or fillets form.