Efficacy of dietary lysophospholipids (Lipidol™) on growth performance, serum immuno-biochemical parameters, and the expression of immune and antioxidant-related genes in rainbow trout (Oncorhynchus mykiss)

Abstract

A 56-day feeding experiment was conducted to evaluate the dietary Lipidol™ (functional ingredient: lysophospholipids) on growth performance, biochemical and immunological parameters, and selected immune and antioxidant-relevant genes expression in rainbow trout. Fish (N = 840; 70.4 ± 1.5 g) were randomly distributed in 12 circular fiberglass tanks and nominated to four treatments: 0 (control), 1, 2, and 3 g Lipidol™ per kg diet. Results indicated that growth performance and feed intake were significantly higher and feed conversion ratio was lower in fish fed with 2 g kg−1 Lipidol™ (p < .05). The lowest albumin, glucose, and high-density lipoprotein, and the highest low-density lipoprotein were observed in fish fed with 2 g kg−1 Lipidol™ (p < .05). Similarly, the most activity of IgM and lysozyme were observed in 2 g kg−1 Lipidol™ and complement proteins were higher in fish fed with 1 and 2 g kg−1 Lipidol™ than other groups (p < .05). The lowest hepatic enzymes activity and the highest villus height were observed in fish fed with 2 g kg−1 Lipidol™ (p < .05). Fish fed with 2 g kg−1 Lipidol™ had significantly higher expression of tumor necrosis factor-α, interleukin-1β and interleukin-8 compared to others (p < .05). Also, the expression of liver genes including superoxide dismutase, catalase, and glutathione peroxidase were significantly up-regulated in 2 g kg−1 Lipidol™ (p < .05). Taken together, supplemental Lipidol™ at 2 g kg−1 in diet could promote the growth performance, serum biochemical parameters, and immune-related genes expression of rainbow trout.