| This experiment through the dietary Vitamin D3(VD3), study on immune related gene expression of peripheral immune organs, cells, tissue morphological changes, immune function and production performance and other aspects of the impact, with a view to explore the VD3on immune function and immune regulation effects, and initially screened to improve the immune response to dietary VD3suitable addition level, gradually accumulated, enriching and developing the Monopterus albus immune nutrition research data, provide the basis for healthy breeding of M.albus.Test methods of single factor experimental design, selection of physical health, average weight of21.7±2.1g M.albus1080populations, were randomly divided into6groups, each group of3repetitions, each repeated60populations.The control group was fed with basic diet (where VD3is0IU/kg VD3), the remaining5test groups in a basal diet were added250,500,1000,2000and4000IU/kg VD3.In a feeding trial of dietary after the20d,40d and60d, from each group was randomly selected6populations M.albus, separately collecting the liver and pancreas, head kidney, spleen, last of the intestinal tract, using RT-PCR technology to detect visceral tissue MHC-II-B, Hepcidin gene expression; using histology observation after the first feeding diets the60d4organization changes in morphology, flow cytometry was used to detect4kinds of tissue apoptosis and cell cycle changes; the feeding cycle, respectively, to collect the blood detection routine blood index and immune function index; feeding trial ended, studied the VD3on growth and digestive enzyme activity and the influence of live bacteria attack after protective effects of M. albus.The results showed that:(1) MHC-II-B gene in4kinds of tissue expression abundance in head kidney, spleen, last of the intestinal tract, liver and pancreas, among the various organizations expressed significant difference (P<0.05); feed the test diet after20D, VD3level was4000IU/kg significantly enhance the head kidney MHC-II-B gene expression amount,2000IU/kg were significantly increased spleen expression (P<0.05); feeding test diets after40d, VD3level was1000IU/Kg at40d could significantly enhance except the spleen and other3kinds of tissue gene expression amount; feeding period up to60d, low level (500IU/Kg) of VD3could significantly promote head kidney and spleen of MHC-II-B gene expression (P<0.05), high dose (4000IU/Kg) VD3the expression amount to a minimum. Results suggest that, in head kidney MHC-II-B gene expression as the main reference, short-term high feeding level (VD32000IU/Kg) diets can improve immune response of M.albus; short-term feeding at1000IU/Kg or500IU/Kg level is appropriate.(2) hepcidin gene in4kinds of tissue expression abundance in liver and pancreas, spleen, head kidney, last of the intestinal tract, among the various organizations expressed significant difference (P<0.05); with VD3dosage increase, M. albus cecropin hepcidin gene in4kinds of tissue expression quantity at the same time showed increased first and then lowering trend;20D,2000IU/Kg add group4organization were in the highest (P<0.05);40and60d,500IU/Kg group of liver and pancreas, head kidney in reached peak (P<0.05);60d,4000IU/Kg processing group VD3will make hepcidin gene expression was significantly decreased (P<0.05).Results indicated that, within a short time of dietary high dose (2000IU/Kg) of VD3can significantly improve the M. albus in visceral tissues of hepcidin gene expression amount; feeding cycle longer, diets supplemented with500IU/Kg VD3significantly increased hepcidin gene expression in M. albus liver and pancreas,head kidney.(3) Low levels of VD3diet group in the view of M. albus spleen splenic corpuscle minimal number; head kidney only sporadic lymphocyte sparsely distributed in the hematopoietic tissue in liver and pancreas; structure integrity, liver cells were arranged closely, liver cell cord evident; intestinal mucosal villous height low, goblet cells with minimal. Intermediate level VD3add group, spleen white pulp ratio of column in the view of increased splenic corpuscle, more clearly visible; head kidney lymphocytes, polymorphonuclear cells proliferation, distribution of lymphoid tissue expansion. High levels of VD3to add group, splenic corpuscle number was decreased, and gradually degraded disappear; visible large lymphocytes, granulocytes and proliferation of hematopoietic tissue distribution area, reduced obviously; local hepatic cell rupture dissolved. Results:the dietary VD3levels can affect the peripheral lymphoid organs (tissues) and histological changes, which may influence the immune function of M. albus.(4) Dietary VD3levels can significantly affect the M. albus peripheral lymphoid organs (tissues) on cell cycle and apoptosis.VD3on the spleen, hindgut and head kidney3organization of cell cycle and apoptosis tendency, proper VD3level (1000IU/kg) promotes cell proliferation, reduced apoptosis, in favor of3kinds of tissue growth and development; VD3deficiency and VD3is too high, will exhibit cell proliferation is blocked, apoptosis rate high.VD3on liver and pancreatic cell proliferation inhibition, add level the higher the stronger the inhibitory effect, and high levels of VD3inducing apoptosis. Results: the proper VD3level (1000IU/kg) can promote M. albus peripheral lymphoid organs (tissues) cell proliferation, apoptosis rate decreased, conducive to the peripheral lymphoid organs growth; high levels of VD3can induce cell proliferation is blocked, apoptosis is accelerated, causing the body to suppress immune functions.(5) Suitable for VD3adding level M. albus promote RBC production and HGB synthesis, and HCT, the elevation of MCHC, PLT number; can significantly improve SOD, GSH-Px, CAT, the AKP, ACP enzyme activity and serum total Pr content. Results:the dietary appropriate VD3levels (500-1000IU/Kg), can significantly improve the nutritional status and the enhancement of M. albus antioxidant ability.(6)The optimal dietary VD3levels (500-2000IU/Kg) can improve M.albus the expression level of IgM, CD4/CD8ratio, serum lysozyme levels, leukocyte, granulocyte and monocyte count, enhances the M.albus humoral immunity, cell immunity and non-specific immune function, increased disease defense capability.(7) The optimum dietary VD3supplementation levels can improve the M.albus survival rate after the Aeromonas hydrophila attack, reduce the severity of various tissues and organs, M.albus has a protective effect.(8) When VD3concentration was500IU/Kg, the rate of weight gain, specific growth rate, survival rate, feed conversion rate, feed coefficient and other indicators are significantly better than the other groups (P<0.05), VD3levels of0and4000IU/Kg, M.albus, survival rate, growth rate feed conversion rate, utilization rate of protein and other indicators have no significant difference (P<0.05); VD3add level within a certain range can significantly improve the foregut and hepatopancreas of the digestive enzyme activity. Results:the suitability of VD3add level could improve the growth performance of M.albus. |
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