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 35day 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 2.40g/wk), harvest biomass (687 to 732g/m2), 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.Alternative & sustainable protein source for shrimp culture.

This study aimed to evaluate the effects of alternative feed ingredients: Insect meal (DI) using non-defatted meal obtained from Acheta domesticus, Microalgae (DM) using a mix of four marine microalgae ((Nannochloropsis gaditana, Tisochrysis lutea, Rhodomonas lens, Isochrysis galbana), Protein and oil from water of tuna canning process (DP&L) and a Mixture (DMix) of the three ingredients, on the growth, feed utilisation, digestibility and composition of meagre juveniles, and the results obtained were compared with a feed similar to a commercial feed used as a control (DC). Results show that the formulated alternative feeds had different effects on fish growth. DMix have a similar growth performance than the control, whereas the other treatments (DI, DM and DP&L) showed a lower final weight. Hepatosomatic and viscerosomatic indices did not show differences among the treatments. Muscle protein content was higher for fish fed with DMix group whereas lipids were significantly higher in DI. In the case of the liver, protein was higher in the liver of fish fed with DI, DM and DP&L, whereas lipids were higher in fish fed with DI and DM, a result that was confirmed with the results obtained in hepatocyte size and lipid accumulation.The nutritional value of the meagre muscle at the end of the study showed that meagre fed with DM and DI diets contained a significantly higher content of monounsaturated and n-6 PUFA, whereas fish from the groups fed with DP&L and DMix had a significantly higher content of DHA and n-3 PUFA with the liver showing similar results. In view of the results obtained, the ingredients assayed in this study might be used as alternative sources of protein and lipids in aquafeeds since no negative effects were detected neither on fish growth, muscle composition or final nutritional value, except in the case of the diet with microalgae (DM), which inclusion rate in the feed must be adjusted and needs more research.