Effects of feeding tilapia by-products flour for piaucu (Leporinus macrocephalits) fingerlings

This trial was carried out to evaluate the effects of feeding Tilapia fillet by-products meal (TF) for piaucu (Leporinus macrocephalus) fingerlings. One hundred and twenty-five fingerlings averaging weight of 0.19 +/- 0.004 g and length of 2.37 +/- 0.28 cm were assigned to a completely randomized design with five treatments of five replicates. The diets were formulated to contain levels of 0.5, 10. and 15% of TF and 0% of TF plus methionine. Diets were fed at 10% of biomass four times a day (8 a.m., 11 a.m., 2 p.m. and 5 p.m.). The means of water abiotic parameters were 7.89 +/- 0.05. 89.93 +/- 0.42, 7.15 +/- 0.10 and 27.10 +/- 0.95 for pH and electric conductivity (mu S.cm(-1)) and dissolved oxygen (mg.L-1) and temperature (degrees C), respectively. At the end of the experiment, the means of survival (SO), final weight (FW), final length (FL), weight gain (WG), conduction factor (CF), and apparent feeding conversion (FC) were measured and calculated. Significant effects of treatments on CF, CA, and FC were detected. The better results were observed with the increasing levels of FT and supplementation of methionine. FL increased and FC decreased linearly with the increasing levels of TC, where the LRP model better adjusted to data when 8.56 and 8.19% of TF levels were estimated. The crude protein (PB) in the carcass presented better results for the treatments with more than 5% of FT and 0% of FT with methionine supplementation. It is recommended to include up to 15% of FT in the diets for piaucu fingerlings to obtain better results of performance and CP deposition in the carcass, that becomes the FT alternative protein source.