Full-Fat Black Soldier Fly Larvae Meal in Diet for Tambaqui, Colossoma macropomum: Digestibility, Growth Performance and Economic Analysis of Feeds

Simple Summary The black soldier fly (BSF, Hermetia illucens) is one of the most studied insects for use in feed, whose larvae (BSFL) can be used to feed fish. In this study, the inclusion of 10.5% wholemeal BSFL meal in the diet of tambaqui (a neotropical fish) resulted in higher growth than fish fed conventional ingredients. The use of wholemeal BSFL meal is more advantageous because it has a lower production cost than defatted BSF meal, as there is no expense involved in the fat extraction process. Wholemeal BSFL meal can be considered a leading ingredient to meet the emerging need for protein ingredients by the feed industry. Black soldier fly (BSF, Hermetia illucens) larvae is a prominent ingredient in aquafeeds due to its high protein and energy contents. This study evaluated the digestibility of full-fat BSF larvae meal (FF-BSFL) and its inclusion in diets for tambaqui, Colossoma macropomum. The apparent digestibility coefficient of FF-BSFL for protein and energy was around of 88%, corresponding to 33.55% and 21.61 MJ kg(-1) of digestible protein and energy, respectively. For the feeding trial, tambaqui juveniles (53.23 +/- 1.07 g) were distributed in a completely randomized experimental design (n = 4; 150 L tanks; 10 fish per tank). Fish were fed diets including 0%, 5.25%, 10.50%, and 15.75% FF-BSFL to apparent satiation for 60 days. Fish fed 10.50% FF-BSFL dietary inclusion showed higher weight gain, feed intake, final biomass, and relative growth rate. The 10.50% FF-BSFL diet presented the highest index of economic profitability. Weight gain fitted a third-degree equation and the optimum FF-BSFL inclusion level was estimated at 11.6%. However, FF-BSFL dietary inclusion up to 15.75% did not impair growth fish performance. FF-BSFL seems to be a promising source of protein and energy for omnivorous fish aquafeed.