Re: Forum: Mass Production of Black Soldier Fly Prepupae for Aquaculture Diets
Black soldier fly prepupae have good nutrient content and very good palatabilty for most fish. Those fish that require high levels of omega 3 fatty acids will need a supplement of fish or crustacean oil. It is also possible to add flax oil or flax meal to get some of the shorter chain omega 3 fatty acids.
To scale up, use a cheap substrate for the black solder fly. One that can be obtained in enough quantity and handled in an expedient manner. Food waste, brewers grains, and poultry bedding may be good substrates for black solder fly. Harvesting must be made to minimize labor. Pre-pupae will craw up an incline and self-harvest if the substrate bins are designed properly.
Moving substrate into and out of bins is also a logistical problem. Since a residual spent substrate should be removed after each batch of soldier fly pre-pupae are harvested, the bin should allow for at least one side to be opened so that residue can be scraped, shovelled, or dragged out. Envision handling methods similar to those used for compost.
The prepupae, once harvested, may be fed live, dried, or dried and ground. Dried and ground pre-pupae can be mixed into a grain based fish diet for pelleting, etc. The oily and gummy nature of the dried pre-pupae requires special attention. Blending the dried pre-pupae with a low-fat grain before grinding may allow grinding in conventional hammer mills. The resulting product can usually be stored until needed to formulate fish feeds.
Utlization of black soldier fly pre-pupae in commercial scale feed milling will require attention to product flow engineering.
I would like to see more on-the-farm processing of fish feed. One method for that was extended in Thailand in the 1990's. A commercial scale meat grinder was utilized to form an extrusion of wet feed formulation, then dried in the sun. The extrusion was broken into pellet-like portions for feeding to fish. The drying process and labor requirement to handle and recover the feed may be mechanized or protected in a greenhouse/conveyor design.
Work with a team including economic and engineering expertise should end with a commercial scale production system.