Effects of dietary protein substitution of fishmeal with black soldier fly larval meal on growth and physiological responses of juvenile striped catfish, Pangasianodon hypophthalmus

A 10‐week feeding trial was conducted to determine the effects of dietary black soldier fly larval meal (BSFLM) on growth performances, digestive enzyme activity, haematological responses and muscle growth‐related gene expression of juvenile striped catfish (Pangasianodon hypophthalmus). Six isonitrogenous and isolipidic diets were formulated with BSFLM to replace fishmeal at 0 per cent (T0), 20 per cent (T20), 40 per cent (T40), 60 per cent (T60), 80 per cent (T80) and 100 per cent (T100). A total of 540 fingerlings were randomly distributed into 18 tanks and fed thrice a day. Growth performance and feed utilization of fish fed T20, T40 and T60 diets were not significantly different from T0 diet. However, increasing the percentage of fishmeal replacement with BSFLM to 100% at an inclusion level of 292 g/kg resulted in a substantial reduction in growth and feed efficiency of striped catfish. Fish fed T80 and T100 diets had significantly lower whole‐body crude protein, crude lipid, total cholesterol and triglyceride value than fish fed other experimental diets, while dietary inclusion of BSFLM had no significant effect on the whole‐body amino acid profile, haematological responses and intestinal and liver protease and amylase activity of striped catfish. However, lipase activity was increased in fish fed T80 and T100 diets. T80 and T100 hepatocytes were shown to have greater congestion in histology than other groups. The relative expression of MyoD and myogenin was significantly maximized in fish fed the T60 diet. Fishmeal may be replaced with BSFLM up to 60 per cent at an inclusion level of 174 g/kg in the diet of juvenile striped catfish.