Optimizing diet costs and growth of yellowtail lambari in semi-intensive systems

This study evaluated the zootechnical performance, cost per kilogram of fish produced and hematological parameters of yellowtail lambari (A. bimaculatus) fed different diets. The diets comprised four treatments: formulated powdered diet with premix (A); formulated powdered diet without premix (B); commercial powdered diet (C) and commercial powdered diet until the fish reached an average weight of 3 g, after which a 1.5 mm extruded commercial diet was fed (D). The fish were fed for 54 days. Diet D resulted in fish with a higher average final weight, weight gain and yield, with a reduction in apparent feed conversion. There was no difference between the treatments in terms of survival before and after purification, carcass yield and hematological parameters of the lambari. However, the cost of the diet per kilo of fish for diet D was higher (R$2.57 per kg) than for diet B (R$1.77 per kg). According to the data obtained in this study, it is possible to provide a formulated diet without harming the growth of the species; however, it may be interesting to combine it with the provision of an extruded diet for fish of at least 3g, to reduce rearing time in excavated ponds.