Effect of dietary carbohydrates and lipids on growth in cachama (Piaractus brachypomus)

Abstract

The effects of diets with three contents of carbohydrates and lipids were evaluated on the growing performance of cachama Piaractus brachypomus juveniles (initial weight 7.8 ± 0.49 g). The experiments were performed a 3 × 3 factorial design (200, 280 and 360 g of carbohydrates and 40, 80 and 120 g of lipids kg−1). Protein content was kept constant in 320 g kg−1 and digestible energy between 11.3 and 16.1 MJ kg−1. Simple effects and interaction of factors on growth performance varied significantly (P < 0.05) indicating dependence among them. The maximum weight gain was observed in fish fed 200 and 280 g kg−1 carbohydrates and 40 g kg−1 lipids. Increase of lipids from 80 to 120 g kg−1 reduced growth significantly. Protein efficiency rate and percentages of protein retention and energy were positively correlated with carbohydrate levels and no significant differences (P > 0.05) were observed with the lipid levels. Results indicate that cachama utilizes carbohydrates as energy source more efficiently than lipids; likewise, lipid levels over 40 g kg−1 depress growth at any carbohydrates level.