| To explore the effects of Flammulina velutipes stem-base(FVS)on AA+ broilers immune index,add different doses of FVS to the scale of breeding broilers feed,investigate relative weight of the digestive organs and immune organ,intestinal villus,lymphocyte conversion rate,cytokine production,immunoglobulin production,Newcastle disease antibody titer and TLR4 and TLR15 mRNA expression level in jejunum mucosa to evaluate the immunological effects of FVS on broilers.A total of 4550 one-day-old healthy AA+ broilers were randomly divided into 5 groups with 7 replicates each.The 5 groups were control group(fed with conventional diet),Low dose group(fed with 2% FVS),middle dose group(fed with 4% FVS),high dose group(fed with 6% FVS)and stage feeding group(stage fed with 6% FVS)during the 43 days.The results were as follows:1.FVS can promote the development of thymus in broilers during the middle stage of growth.The thymus index of broilers in low dose group,middle dose group and stage feeding group was significantly higher than that in control group,and there was no pathological change in thymus morphology of broilers.2.Diets with high dose and stage feeding of FVS could improve the T lymphocyte transformation rate in broilers.This may be because FVS promotes the proliferation of T lymphocyte and promotes the cellular immune function of broilers by promoting the development of thymus gland.3.On the whole growth stage,high dose of FVS can improve the level of antibody against Newcastle disease in broilers.During the middle and late growth stage,the antibody titers of Newcastle disease of broilers increased steadily.This shows that the high dose group of broilers immune,compared with the control group,the effect is obvious.4.FVS increase serum IL-4,IL-2,IL-6 and IFN-gamma content in different period of broiler growth,may promote Th0 cells to Th1 and Th2 cell differentiation,and enhance cell immunity and humoral immune function in broilers.5.Compared with the control group,FVS could increase the IgA content in the middle and late stages of broiler growth,and increase the IgG content in the early and middle stages of broilers,and increase the IgM content in the middle growth stage of broilers.The results showed that the contents of immunoglobulin in broilers increased at the middle stage of growth,which indicated that FVS could improve the humoral immune function of broilers and might be concentrated in the mid stage of broiler growth.6.The addition of FVS in diets significantly increased the relative weight of the duodenum and jejunum at the later growth stage of broilers.This indicated that FVS could promote the development of the duodenum and jejunum at the later stage of broiler growth.7.Low and medium doses and stage feeding of FVS could improve the intestinal V/C and enhance the intestinal absorption capacity of broilers.8.Stage feeding of FVS could significantly increase the IL-2 content of ileum in late growth stage of broilers.9.High dose of FVS could significantly improve the IL-4 content in the small intestine of broiler chickens at the early stage of growth.10.Stage feeding of FVS could significantly improve the S-IgA content in the small intestine of broiler chickens at the early stage of growth.11.On the whole growth period,low dose,middle dose and phase feeding FVS expression was up-regulated in broiler TLR4 and TLR15 mRNA play a key role in improving the mucosal immune function of broilers and maintaining the intestinal mucosal immune barrier in broilers.To sum up,FVS can promote the development of immune organs and small intestine,promote the expression of TLR4 and TLR15 mRNA in small intestinal mucosa,and improve the cellular immunity and humoral immune function of broilers. |
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