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

Abstract

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.

Insect lipid in fish nutrition: Recent knowledge and future application in aquaculture

“…It is interesting to note that the dietary adjustments had no effect on the digestion of the majority of n−3 fatty acids (18:4n−3, 20:5n−3, 22:5n−3, and total n−3 fatty acids). Regarding the dietary insect oil inclusion effect on digestive enzyme activity in fish, Sudha et al 79 recently reported no significant change on amylase, lipase and protease activity in the intestine and liver of stripped catfish fed BSFLO compared with FO, MO, BCSO and FSO. Similar to this, Belghit et al 17 showed that dietary inclusion of insect meal and insect lipid (BSFLO) had no discernible impact on the activity of the digestive enzyme trypsin and the level of total bile acids in the intestine of freshwater‐reared Atlantic salmon.…”

“…For instance, because BSFLO contains linoleic, 18:2n−6, and linolenic, 18:3n−3, in concentrations similar to those of SBO and other vegetable oils, freshwater fish may be able to successfully use it to biosynthesize n−3 LC‐PUFA. Based on the published research, insect oil has been used with differing degrees of effectiveness to replace FO, SBO, moringa oil, sesame oil, flax seed oil, camelina oil, black cumin seed oil, and blends of terrestrial oils in the diets of different farmed fish species 14,23,44,78,79 . However, with all oil substitution work in aquaculture it is important also to look at the lipid content of the meal in the diet, especially FM.…”

“…Overall, they concluded BSFLO is a better lipid source than YMO or SWPO for juvenile mirror carp. In a recent study, Sudha et al 79 evaluated BSFLO along with other vegetable oils, namely MO, BCSO and FSO in the diets of juvenile striped catfish ( Pangasianodon hypophthalmus ). After 10 weeks of feeding, they concluded that the striped catfish juveniles can be reared on diets in which FO has been replaced with BSFLO and MO without any adverse effects on growth and feed utilization performances.…”

“…In contrast, Li et al 26 reported no significant effect of ALT and AST values in Jian carp fed diets where SBO was replaced with BSFLO suggesting that BSFLO does not affect hepatopancreas health. Recently, Sudha et al 79 stated no significant variations in haematological indices like red blood cell (RBC), white blood cell (WBC), haemoglobin (Hb), haematocrit (Ht), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC) and mean corpuscular volume (MCV) in striped catfish fed BSFLO compared with FO, MO, BCSO and FSO. No significant changes of these parameters indicates the capability of striped catfish to using BSFLO along with other terrestrial oils without any negative effects on any physiological processes like delivering oxygen to vital organs, fending off external contaminants, or maintaining overall health.…”