Dietary replacement of soybean meal with black soldier fly larvae meal improves growth and disease resistance in juvenile Pangasius bocourti

Abstract

This eight week long experiment was performed to study the effects of substitution of crude protein from soybean meal (SBM) with non-defatted black soldier fly (Hermetia illucens) larvae meal (BSFLM) on growth, nutritional quality, haematology, biochemistry, oxidative stress biomarkers, and bacterial disease resistance in juvenile basa (Pangasius bocourti). Four isonitrogenous and isolipidic diets (30% crude protein) were formulated to replace 0% (T0), 40% (T40), 80% (T80) and 100% (T100) of crude protein from SBM with BSFLM. Fingerlings (initial weight = 18.00 ± 1.25 g, n = 135) were stocked in aquaria. At end of the growth experiment, fifteen fish from each group were exposed to bacterial (Staphylococcus aureus) challenge (0.80 CFU/ml) for fifteen days. Fish in BSFLM substituted groups showed significantly higher growth and condition as compared to those in T0. Inclusion of BSFLM did not affect the chemical composition, profile of amino acids, and fatty acids in fish. However, the levels of lauric acid, linoleic acid, α-linolenic acid, decosahexanoic acid, and eicosapentanoic acid increased in BSFLM fed fish. The concentration of catalase, superoxide dismutase and lysozyme increased with addition of BSFLM in diet at end of the growth experiment. These oxidative stress biomarkers indicate that replacement of SBM with BSFLM up to 80% improved the growth and disease resistance in basa against gram-positive bacteria. BSFLM can be a future alternative protein source for commercial production of aquafeed for this species.