Replacement of fish oil with black soldier fly larvae oil and vegetable oils: Effects of growth, whole-body fatty acid profile, digestive enzyme activity, haemato-biochemical responses and muscle growth-related gene expression of juvenile striped catfish, Pangasianodon hypophthalmus

A 10-week feeding trial was conducted to evaluate the effects of dietary replacement of fish oil (FO) with black soldier fly larvae oil (BSFLO) and vegetable oils, namely moringa oil (MO), black cumin seed oil (BCSO) and flax seed oil (FSO) on growth and whole-body fatty acid profile, digestive enzyme activity, haemato-biochemical responses and muscle growth-related gene expression of juvenile striped catfish, Pangasianodon hypophthalmus. Five isonitrogenous (313.34 g kg(-1)) and isolipidic (81.82 g kg(-1)) experimental diets were formulated. A total of 450 fingerlings (5.02 +/- 0.1 g per fish) were randomly distributed into 15 tanks and fed thrice a day. The final weight gain was significantly improved in fish fed FO (45.7 +/- 0.72 g/fish), BSFLO (45.53 +/- 1.32 g/fish) and MO diet (47.2 +/- 0.26 g/fish) when compared to BCSO (36.3 +/- 1.05 g/fish) and FSO (35.83 +/- 0.71g/ fish) diets. The lower value of daily weight gain was recorded in the FSO and BCSO treatments compared with other oils could be due to effects on stress resistance and immunosuppression in fish, whereas the whole-body EPA and DHA content of fish fed with FSO and FO diets was substantially higher than fish fed with other experimental diets. However, the relative expression of Myo D and Myogenin was upregulated in fish fed with FO, BSFLO and MO diet than the BCSO and FSO diet. Present results indicate that the juveniles can be reared on diets in which FO has been replaced with BSFLO and MO, with no significant effects on fish performance.

Automated summary

This study evaluated the effects of replacing fish oil with black soldier fly larvae oil and vegetable oils on the growth and body characteristics of juvenile striped catfish. The results showed that replacing fish oil with black soldier fly larvae oil and moringa oil improved the weight gain of the fish. However, feeding fish with flax seed oil and black cumin seed oil resulted in lower stress resistance and immune suppression.