Abstract:This experiment was conducted to investigate the effects of dietary mulberry leaf flavonoids on growth performance, serum biochemical parameters, antioxidant indices and anti-hypoxic stress ability of Litopenaeus vannamei. A total of 960 L. vannamei individuals (initial body weight:1.32±0.01 g) were divided into 6 groups, with 4 replicates per group and 40 shrimp per replicates. Six diets were formulated to contain 0 mg/kg, 10 mg/kg, 50 mg/kg, 100 mg/kg, 150 mg/kg, and 300 mg/kg diet of mulberry leaf flavonoids. The trial ran for 50 days. The survival rate, growth related indicators, serum biochemical indexes, antioxidant index and resistance to hypoxia stress were determined. The results indicated that:(1) there were no significant differences in the survival rate (SR), weight gain rate (WGR), specific growth rate (SGR), or feed conversion ratio (FCR) among the groups (P>0.05). WGR was highest in the 50 mg/kg group, 6.76% higher than the control group. (2) There were no significant effects on whole-body composition (P>0.05). (3) Adding 150 mg/kg and 300 mg/kg of mulberry leaf flavonoids to the diet significantly increased the activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in the serum of L. vannamei (P<0.05). (4) Adding 10–300 mg/kg of mulberry leaf flavonoids to the diet significantly increased the total antioxidant capacity (T-AOC) in the serum and liver, and significantly decreased the malondialdehyde (MDA) and lipid peroxide (LPO) contents in the liver of L. vannamei. Adding 50 mg/kg mulberry leaf flavonoids significantly increased glutathione peroxidase (GSH-Px) activity in the serum (P<0.05). (5) After 2 h of hypoxic stress, the cumulative mortality of the 10 mg/kg and 50 mg/kg groups were significantly lower than the control group, and after 4 h, the cumulative mortality of the 10 mg/kg, 50 mg/kg, and 100 mg/kg groups were significantly lower than the control group (P<0.05). In conclusion, the evaluative index of T-AOC in the serum and regression equation analyses showed that the optimal supplemental level of mulberry leaf flavonoids in the diet of L. vannamei was 56.18 mg/kg. Adding 10–100 mg/kg mulberry leaf flavonoids to the diet improved the anti-hypoxic stress ability of L. vannamei.