Farinha de vísceras de aves em rações para a tilápia do Nilo (Oreochromis niloticus L.) durante a fase de reversão sexual

Abstract

The objective of this work was to evaluate the performance, survival and effectiveness of reversion of Nile tilapia fry (Oreochromis niloticus L.) fed with rations containing growing levels of inclusion of poultry by products (FVA). Five hundred Nile tilapia fry were used with two days of age, allotted to a completely randomized design with five treatments and five replications, and the experimental unit an aquarium 30 L with 20 fry. Five rations were elaborated with levels of inclusion of FVA 0; 20: 40, 60% and one of 60% of FVA plus synthetic lysine supplementation. The rations were isocalorics, isocalcics, isofosforics and isoproteic, with 60 mg of a-metiltestosterona/kg. 38.6% of digestible protein and 3700 kcal of digestible energy/kg: the ration with lysine inclusion was isoaminoacidic for lysine in relation to the ration without inclusion of FVA. The ad libitum feeding was made four times a day. At the end of the experimental period, it was evaluated the final weight (PF), total length (CT), survival (SO) and reversion effectiveness (ER). A linear increase was observed for PF and CT with the increase of the inclusion of FVA in the ration. However, for SO the ration without FVA was inferior to the others.Rations without inclusion of FVA and with inclusion of 20% of lysine showed PF and CT medium inferiior and only the ration without FVA was inferior for SO. Concluding, FVA could be used in rations for the Nile tilapia during the sexual reversion.