Evaluation of bioflocs derived from confectionary food effluent water as a replacement feed ingredient for fishmeal or soy meal for shrimp

It is important to explore the use of alternative ingredients for soybean and fishmeal in aquaculture feeds because the demand and cost for those ingredients are expected to increase in the near future and long-term. Meanwhile, the food processing industry produces large quantities of wastes that often contain organic solids and nutrients (e.g. nitrogen waste and phosphorus) which can be converted in microbial protein (bioflocs) using suspended growth biological reactors. Bioflocs that were collected from such a reactor that treats confectionary food processing effluent water were dried and in shrimp feed as a replacement for soybean and fishmeal. A control diet (without bioflocs) was compared to three diets that replaced soybean (10, 20, and 30% biofloc inclusion) and two diets that replaced fishmeal (10 and 20% biofloc inclusion). The control and biofloc diets were formulated to be equivalent for levels of crude protein, total fat, crude fiber, calcium, magnesium, phosphorus, potassium, and sodium. Five juvenile shrimp were stocked per tank and each dietary treatment was tested using 8 replicates over a 35 day feeding trial. Dietary treatments had some impact on shrimp performance. No differences (P > 0.05) in shrimp performance were observed between the control and the diets that included bioflocs for survival (97.5 to 100%), growth (2.16 to 2.40 g/wk), harvest biomass (687 to 732 g/m(2)), or food conversion ratio (1.50 to 1.66). These results indicate the bioflocs harvested from a suspended growth biological reactor that treats food effluent water can successfully be used in shrimp diets. Statement of relevance: Alternative & sustainable protein source for shrimp culture. (C) 2015 Elsevier B.V. All rights reserved.