Abstract:

In order to improve the growth performance and disease resistance ability of Litopenaeus vannamei, Compound Chinese herb composed of equal Radix astragalus, Rheum officinale, Glycyrrhiza uralensis and Radix scutellaria was supplemented into shrimp diets to investigate its effects on growth performance and non-specific immunity of Litopenaeus vannamei. Shrimp Litopenaeus vannamei was randomly divided into three treatments: control treatment was fed with basic diet; D1 group was fed with basic diet supplemented with 1% compound Chinese herb continuously; 6D1-6D0 group fed with herb-containing diet for 6d and then with basic diet for 6 d. The growth performance and the activities of hydrolymph phenoloxidase (PO), lysozyme (LSZ) and superoxide dismutase (SOD) at different sample time were measured. The shrimps were challenged with Vibrio parahaemolyticus at the 14th day and 28th day respectively. The results indicated that the growth rate and weight gain rate of shrimp in D1 group increased significantly than that in control group (P＜0.05); there was no significant difference of growth rate and weight gain rate between 6D1-6D0 and control group (P＞0.05). The activities of immune enzymes were improved significantly when shrimp was fed diets supplemented with 1% compound Chinese herb. The challenge test demonstrated the immune protective rate of treatment D1 and 6D1-6D0 was 68.3%, 27.2% at the 14th day, and 91.6%, 45.8% at the 28th day respectively. The results indicated the compound Chinese herb could improve the disease resistance of Litopenaeus vannamei to V. parahaemolyticus.