Rutin is a natural flavone derivative with many biological activities. To investigate?the effects of dietary rutin on growth, serum antioxidant response and flesh quality?of grass carp (Ctenopharyngodon idella), six diets were prepared with the rutin inclusion

at 0 (control diet), 0.2, 0.4, 0.6, 0.8 and 1.0 g/kg, respectively. Grass carp with?initial body weight of 18.5 ± 0.2 g were fed with the six diets for 60 days. The weight?gain was increased from 348.5% (the control) to 364.4%, 366.5% (p < .05), and feed?conversion ratio was decreased from 1.56 (the control) to 1.49, 1.48 (p < .05), respectively,?by the supplementation of 0.8 and 1.0 g/kg rutin in diets. Serum SOD activity?was increased by the addition of 0.2–1.0 g/kg rutin (p < .05), and serum MDA content?was decreased by the addition of 0.4–1.0 g/kg rutin (p < .05). The inclusion of 1.0 g/kg rutin and 0.6–1.0 g/kg rutin significantly increased the collagen content and the?total free amino acids in flesh (p < .05), respectively. The content of n-3 PUFA in?flesh was also promoted by the inclusion of 0.2 and 0.6 g/kg rutin (p < .05). However,?dietary rutin did not significantly affect the flesh texture and water-holding capacity.?In conclusion, dietary rutin could improve the growth, antioxidant response ability?and flesh quality of grass carp, and the recommended supplemental level of rutin was?0.8–1.0 g/kg.