Effects Of Oridonin On Regulation Of Immune Stress In Broilers

As the development of intensive breeding industry in broiler,many stress factors damage the animal welfare and productivity,especially the immune stress induced by the bacterial infections.Broilers are prone to immune stress under certain unsuitable physiological and environmental conditions compared to the mammals.Oridonin possesses an extensive spectrum of antioxidant,anti-inflammatory,and anti-bacterial properties,however,there is little study on the breeding industry.In the present study,we use the lipopolysaccharide(LPS)to mimic immune stress and oxidant stress in broilers to investigate the protective effects of different levels of oridonin on growth performance,antioxidant capacity and anti-inflammatory capacity of broilers,and to provide a theoretical basis for its application in the production of broilers.This study mainly contained three experiments:1.The effects of dietary oridonin supplementation on growth performance and serum biochemical parameters of broilers challenged with LPS.In trial 1,a total of 384 1-d-old male Arbor Acre broiler chickens were randomly assigned to 8 treatments with 6 replicate cages per treatment and 8 birds per replicate.There were four dietary treatments:the control group(birds fed the basal diet),the ORI 50 group,the ORI 80 group and the ORI 100 group(birds fed the basal diet supplemented with 50,80,100 mg/kg Oridonin,respectively).Broilers were intraperitoneally injected with either 250?g LPS per kg body weight or an equivalent amount of sterile saline at 16,18 and 20 d of age.LPS decreased the ADG,ADFI and FCR of broiler chickens(P<0.05),Oridonin supplementation had no effects on growth perfomance whether before or after LPS injection(P>0.05).Additionally,the LPS-induced increases in the concentrations of serum AST,ALT,TP and GLB were dramatically decreased by Oridonin in both serum(P<0.05),with the same tendency also noted for ALB compared with the control groups(P=0.089).2.The effects of dietary oridonin supplementation on serum and liver antioxidant capacity of broilers challenged with LPS.The experiment design was same as that of trial 1.In this experiment,the LPS-induced increases in the concentrations of MDA and decreases in activities of T-SOD,T-AOC and CAT were dramatically attenuated by Oridonin in both serum and liver(P<0.05).Additionally,LPS down-regulated the mRNA expressions of Nrf2,Cu/Zn-SOD,Mn-SOD,GPxl and CAT in the liver(P<0.05),However,oridonin inclusion increased the liver mRNA expression levels of Nrf2,Cu/Zn-SOD,Mn-SOD,CAT and GPxl(P<0.05)as compared to broiler chickens in control groups,but there was no effect on the expression of Nrfl(P>0.05)in broilers supplemented with oridonin as compared to the control groups.There was a significantly Stress x Diet interactions on liver MDA content(P<0.05).3.the effects of dietary oridonin supplementation on immune function of broilers challenged with LPS.The experiment design was same as that of trial 1.In this experiment,LPS stimulation increased the relative weight of spleen and bursa(P<0.05),Oridonin inclusion markedly attenuated the increased spleen index(P<0.05).LPS stimulation increased the WBC,LMN,LYMR,MID,MCC(P<0.05),but there was no effect on RBC and PCV(P>0.05).Oridonin inclusion markedly decreased the abnormal increased blood characteristics(P<0.05),and has no effect on RBC and PCV(P>0.05).LPS stimulation increased the content of IgA,IgG in both serum and spleen(P<0.05).Oridonin inclusion markedly decreased the increased IgA level(P<0.05),but has no effect on IgG in both serum and spleen(P>0.05).LPS stimulation increased the level ofTNF-?,IL-1?,IL-6,IL-10 andBLys in both serum and spleen(P<0.05).Oridonin inclusion markedly decreased the increased TNF-?,IL-1?,IL-10 and BLys(P<0.05),but has no effect on the increased IL-6(P>0.05).Furthermore,LPS markedly up-regulated the mRNA expressions of NF?B,TNF?,TLR4,IFN?,IL-1?,IL-6,IL-8,IL-10,IL-4 and BLys(P<0.05),Oridonin supplementation markedly down-regulated the increased inflammatory cytokines mRNA expression levels(P<0.05),but has no effect on the increased expression of IL-6(P>0.05).In conclusion,diets supplementation with an optimal level of 100 mg/kg oridonin could exerted certain protective effects on the LPS-impaired growth performance and improve the antioxidant capacity and anti-inflammatory capacity of broilers under LPS stress.