The Primary Investigation To Immunostimulatory Fatigue For American White Shrimp, Litopenaeus Vannamei And Chinese Shrimp,Fenneropenaeus Chinensis

Feeding experiments were conducted to investigate the effects of dietary β -1, 3/1, 6- glucan on innate immune parameter of American white shrimp, Litopenaeus vannamei and Chinese shrimp, Fenneropenaeus chinensis for 66 days and 42 days respectively. During the feeding period, some successive immunostimulation were conducted with different immunostimulants on the shrimp which had been fed β -1, 3/1, 6- glucan diet for a long time (Litopenaeus vannamei: 23^th day, Fenneropenaeus chinensis : 24^th day). Using this feeding strategy to discover a suitable method to evoke the immunostimulatory fatigue.Results of the experiment study are presented as follows:1. The immunostimulatory fatigue which was proposed by Chang(2000) emerged in the parameter of Plasma Protein Concentration of Amercian white shrimp, Litopenaeus vannamei. However the immunostimulatory fatigue wasn't evoked by the successively feeding strategy.2. Dietary β -1, 3/1, 6- glucan could significantly improve the Plasma Phenoloxidase Activity and Plasma Protein Concentration(P<0.05), but have no significant effects on other parameters.3. The effects of the successive immunostimulation with different immunostimulants on the immune parameters were presented as follows: Dietary peptidoglycan significantly improved the Alkline Phosphatases (AKP) activity on 44^th day(P<0.05); Dietary levamisole significantly inhibited Acid Phosphatases(ACP) activity on 32^th day(P<0.05); Dietary lactoferrin significantly improved Alkline Phosphatases(AKP) activity on 44^th day(P<0.05).4. Studies showed that the immunostimulatory fatigue didn't present on any immune parameters after a long time using of β-1, 3/1, 6-glucan dietson Chinese shrimp, Fenneropenaeus chinensis.5. P -1 , 3/1 , 6- glucan diets could significantly improve the Plasma Phenoloxidase activity in Chinese shrimp, Fenneropenaeus chinensis(?<0.05), but have no significant effects on other parameters.6. After feeding glucan diet, those successive immunostimulants had no significant effects on the immune parameters of Chinese shrimp, Fenneropenaeus chinensis.