Abstract
This study examined how the dietary lipid levels influence growth performance, lipid metabolism, oxidative response and hepatopancreatic health in Macrobrachium rosenbergii. A total of 720 post-larvae (0.86 ± 0.01 g) were divided into 4 groups according to the lipid levels in 43% protein-contained diets: 6% (L6), 8% (L8), 10% (L10), and 12% (L12). The results exhibited a significant increase in both the weight gain rate (WGR) and specific growth rate (SGR) in the L8 group (p < 0.05). Hepatopancreatic lipid metabolism genes (fas, acc, srebp1, and fabp) showed increased expression at higher dietary lipid levels (p < 0.05). The expression of ampk was significantly reduced, whereas the expression of atgl was increased in the L8 group (p < 0.05). Additionally, the activities of total superoxide dismutase (SOD), glutathione S-transferase (GST), and total antioxidant capacity (T-AOC) level were significantly higher in the L8 group, while the content of malondinaldehyde (MDA) was significantly reduced (p < 0.05). H&E staining of the hepatopancreas revealed that high-lipid diets resulted in severe hepatopancreas damage. Moreover, the L8 group exhibited consistently high cumulative survival rates under both ammonia nitrogen and high-temperature stress (p < 0.05). In conclusion, this study recommends a dietary lipid level of 8% to optimize growth performance in M. rosenbergii under high-density rearing conditions (70 prawns/m(3)).