Relations Between Changes Of Intestinal Microflora And Immune Function Of Grass Carp (Ctenopharyngodon Idellus)

Grass carp (Cteropharyngodon idellns) were fed medicated feed containing 2% rhubarb (Rheum officinale) or isatis root (Isatis tinctorid) respectively in this study. Then on the days(0d, 1d, 4d, 7d, 14d, 21d, 28d) before and after fed medicated feed were samples carried out respectively by surveying changes of number and composition of intestinal microflora including fore-gut, mid-gut and hind-gut> phagocytic activity of leukocytes in the blood and lysozyme activity in the serum of grass carp, at the same time responding intestine tissue were fixed, embedded by paraffin and sliced up to observe changes of lymphocytes in intestine tract of grass carp, in order to find the relation between changes of intestinal microflora and immune funciton of grass carp. The results were as follows:1) The number of bacteria in the intestine tract of grass carp ranged from 105-108cfu/g, and the intestinal predominant flora was Aeromonas and Enterobacteriaceae, composition percentage of whose put up a relation of ebb and flow.2) The composition percentage of Aeromonas in intestine tract declined and the composition percentage of Enterobacteriaceae rose with the days, while phagocytic percentage and phagocytic index of leukocytes of grass carp were raised significantly. This showed that there may be some relation between changes of predominant flora Aeromonas^ Enterobacteriaceae and promotion of phagocytic activity of leukocytes in the blood.3) There was no obvious relation between changes of number and compositon of intestinal microflora and changes of lysozyme activity in the serum of grass carp. That is to say, there weren't the same compounding changes on lysozyme activity in the serum as changes of number and of intestinal predominant flora Aeromonas and Enterobacteriaceae after fed with rumbarb and isatis root.4) Numbers of lymphocytes in intestine tract of grass carp were obviously increased after fed medicated feed containing rhubarb and isatis root, and composition percent of the predominant flora Aeromonas in the intestine tract increased and composition percent of Enterobacteriaceae declined with days. Although their changes have no obvious relation with the growth of lymphocytes number, changes of the intestinal predominant flora Aeromonas and Enterobacteriaceae have some effect on the growth of lymphocytes number in intestine tract. On the other hand, that may be owing to the immune promotion of rhubarb and isatis root.