Influence of Immunopolysaccharide (Yeast Cell Wall)on Resistance to Vibrio harveyi of Penaeus vannamei by Oral Administration

The pacific white Shrimp,Penaeus vannamei were fed with feed supplemented with immunopolysaccharied(yeast cell wall)at the ratio of 100.0,200.0,300.0,400.0 and 500.0 mg·kg~(-1)Bm,respectively. 28 days later, in order to find out the effect of yeast cell wall of different ratios on immuno-related enzyme activities in Penaeus vannamei as well as their resistance to Vibrio harveyi,the acid phosphatase(ACP), alkaline phosphatase(ALP)and peroxidase (POD)in the serum, hepatopancreas and muscle were monitored respectively. Meanwhile, the Penaeus vannamei were challenged with live Vibrio harveyi.The results showed that when fed with feed supplemented with 100.0 mg·kg~(-1)Bm yeast cell wall, the ACP and ALP activities in serum and muscle of Penaeus vannamei were significantly boosted(t-test,P0.05), while the ACP ,ALP and POD activities in hepatopancreas of Penaeus vannamei were strikingly significantly boosted (t-test,P0.01).There were no significant differences among groups with different ratio of yeast cell wall (t-test,P0.05). The study showed that when yeast cell wall were added in the feed at the ratio of 100.0 mg·kg~(-1)Bm,satisfying results can be achieved.