The optimal dietary level of dry grape extract and its effect on the growth performance and antioxidant activity of the white shrimp Litopenaeus vannamei

Abstract

The optimal dietary level of the dry grape extract was determined based on the growth performance and in vivo antioxidant activity of the white shrimp Litopenaeus vannamei. A control diet containing 1000 ppm vitamin E without added grape extract and four other diets containing 125 (N125), 250 (N250), 375 (N375) and 500 ppm (N500) dry grape extract were formulated. Each aquarium contained twenty 2.45 g shrimp larvae and the shrimps were randomly assigned to one of three replicates of the above five treatment diets. The shrimp were fed to satiation three times daily for seven weeks. The final weight, weight gain percentage and specific growth rate of the shrimp fed the diet containing 250 ppm dry grape extract were significantly higher than those of shrimp fed the control diet and the diets containing 125 and 500 ppm dry grape extract. The growth parameters of the shrimp fed diets containing 250 and 375 ppm dry grape extract were not significantly different. The levels of superoxide dismutase (SOD) activity of the shrimp fed the control diet and the diets supplemented with 375 and 500 ppm dry grape extract were significantly higher than those fed the diet containing 125 ppm dry grape extract, while the thiobarbituric acid-reactive substance (TBARS) levels of the shrimp fed the diet containing 125 ppm dry grape extract were significantly higher than those of shrimp fed the other diets. It is suggested that 321.3 ppm dry grape extract should be the optimum level suitable for white shrimp to reach their maximum growth.