Black solider fly larvae meal as a protein source in low fish meal diets for Atlantic salmon (Salmo salar)

Abstract This study determined the optimal dietary inclusion level of black soldier fly larvae meal (BSFM) on the digestibility and growth of Atlantic salmon (Salmo salar). In the digestibility experiment, salmon were fed diets that contained a 70:30 blend of reference diet to test ingredient, comparing BSFM, soy protein concentrate, and corn protein concentrate as the test ingredients. In the growth study, salmon (mean initial weight 2.8 ± 0.1 g fish−1), were fed diets containing 0.0 g kg−1 (control), 100 g kg−1, 200 g kg−1 and 300 g kg−1 BSFM. Four hundred and eighty fish were held in a flow-through freshwater system, with 30 fish / tank (30L), 4 tanks / diet. Salmon were fed for 112 days with measurements recorded every 28 days. Digestibility coefficients of BSFM was generally over 75%, with dry matter and gross energy showing higher coefficients in BSFM than CPC and SBM. Mineral digestibility was generally higher in BSFM compared with CPC and SBM. Salmon fed up to 200 g kg−1 showed similar growth performance to salmon fed the control diet. However, salmon fed 300 g kg−1 BSFM diet gained significantly less weight, had the lowest SGR, TGC and the highest FCR than salmon fed any other treatment, while all other treatments were not different from each other (p