Partial replacement of fish oil with terrestrial lipid blend and effects on growth performance,body composition,immune parameter and growth‐related genes in yellow drum (Nibea albiflora)

The imbalance of fish oil (FO) supply and demand has motivated efforts to identify an alternative for aqua feed. An 8‐week feeding trial was conducted to evaluate the effects of dietary fish oil partial replacement with mixed oil from linseed and lard (1:1) on growth, body composition and immunity when the N3 long‐chain polyunsaturated fatty acid (N3 LC‐PUFAs) requirement is met for Nibea albiflora. Two types of experimental diets were formulated with 100% fish oil (FO) or 69% mixed oil (Mix). The results indicated that the Mix diet significantly improved the specific growth rate (SGR), weight gain (WG), feed efficiency ratio (FER), muscle tissue growth hormone receptor (GHR), insulin‐like growth factor 1 (IGF1) and insulin‐like growth factor 1 receptor (IGF1R) gene expression of the yellow drum (p < .05). No significant difference in the survival rate (SR), feed intake (FI), hepatosomatic index (HSI), viscerosomatic index (VSI), condition factor (CF), N3 PUFA percentage, liver antioxidant enzyme activities or pro‐inflammatory gene expression was observed between the two treatments. Therefore, terrestrial blend lipid from linseed and lard could be used as an alternative for dietary fish oil without compromising growth performance and immunity for the juvenile yellow drum.