| The effect of global warming increases the frequency and aggravates the negative impacts of heat stress on poultry production,accompanied by lower performance,physiological metabolism disorders,organ damage and inflammatory,especially in tropical and subtropical areas.Therefore,it was of great significance to study the physiological metabolism changes and mechanism of organ damage induced by heat stress in poultry,and to develop natural botanical nutraceutical which can alleviate heat stress in poultry production.A total of 480 healthy yellow-feather broilers(28-d-old,male)were individually weighed(the average weight was 717g)and then randomly allotted to 5 treatment groups with 6 replicates of 16 broilers each.Among them,the thermos-neutral group(TN)was housed in an environmental controlled chamber at 24±2? and fed with the basal diet.Birds in the remaining 4 groups were subjected to heat stress in another controlled chamber at high temperature 37±2? for 8 h/d(0930-1730 hours)and 24±2? for the remaining time,and received 1 of 4 diets: the basal diet and the basal diet with 200,350,500 mg/kg of resveratrol,referred to as HT,HT200,HT350 and HT500,respectively.The trial lasted for 14 consecutive days(28-day-old is the d 1 of the trial).In addition,another total of 96 healthy birds(28-d-old,male)were randomly allotted to 2 treatment groups(TN and HT)with 3replicates of 16 broilers each,this trial lasted for 3 consecutive days for i TRAQ proteomics,T-test in R software was used to evaluated the difference between TN and HT,proteins with a fold change of >1.20 or FC<0.83 and results were regarded as statistically significant at p-values less than 0.05.The main results were as follows:1 Effect of heat stress and resveratrol on growth performance and serum parameters of yellow-feather broilersThe results revealed that heat stress reduced ADFI(P=0.013),ADG(P <0.001)and semi-eviscerated percentage,eviscerated percentage,chest muscle percentage(P<0.05),and increased(P=0.009)the feed to gain ratio(F/G),and increased rectal temperature(P<0.05)from d 3 when compared with group TN.Resveratrol supplementation improved ADG(P=0.001)and semi-eviscerated percentage,eviscerated percentage,leg muscle percentage(P < 0.05),and decreased(P < 0.05)rectal temperature from d 3 when compared withheat-stressed group without resveratrol.In addition,supplementation with resveratrol at 350 or 500 mg/kg lowered(P<0.05)the contents of corticosterone,adrenocorticotropic hormone,cholesterol,triglycerides,uric acid,malonaldehyde,and activities of aspartate aminotransferase,alanine aminotransferase and lactate dehydrogenase,increased(P<0.05)the levels of triiodothyronine,the ratio of triiodothyronine to thyroxine,total protein,glutathione,and activities of alkaline phosphatase,total superoxide dismutase,catalase and glutathione peroxidase,though with few fluctuation.In conclusion,supplementation with resveratrol can improve the growth performance by positively regulating serum metabolic parameters and alleviating tissue oxidant damage of broilers under heat stress.2 Effect of heat stress and resveratrol on immune organ index,morphology and serum globulin,complement level of yellow-feather broilers underThe results showed that heat stress significantly deceased(P < 0.05)organ index of thymus,spleen and bursa of fabricius,decreased the content of C3,C4 and IgG,IgM at different time point,for histologically,induced damage on the spleen,thymus and bursa of fabricius.Supplementation with resveratrol at 350 or 500 mg/kg increased(P<0.05)organ index of thymus,spleen and bursa of fabricius,alleviated organ damage,increased the levels of serum C3,C4 and IgG,IgM,improve the immune function of heat-stressed broilers.3 Resveratrol alleviates heat stress-induced impairment of intestinal barrier integrity in yellow-feather broilersCompared with the TN group,birds in the HT group decreased(P<0.05)villus height,villus height to crypt depth ratio(V/C)of jejunum and ileum,jejunal mucosa m RNA levels of mucin-2,secreted immunoglobulin A(sIgA),claudin-1,zona occludens-1 and serum levels of IFN-?,and increased(P < 0.05)crypt depth,mRNA levels of HSP70,HSP90,NF-?B,mucin-4,claudin-2 and serum levels of endotoxin,IL-1?,IL-4,IL-6 and TNF-? on d3 and d14,except for claudin-1 on d14 and TNF-? on d3(P>0.05).Compared with HT group,supplementation with 500 mg/kg resveratrol decreased(P<0.05)crypt depth(in jejunum on d3,ileum on d14),mRNA levels of HSP70,HSP90,NF-?B,mucin-4,claudin-2 and serum levels of endotoxin,IL-1?,IL-4,IL-6 and TNF-?,and increased(P<0.05)villus height,V/C,m RNA levels of mucin-2,sIgA,claudin-1,zona occludens-1 and serum levels of IFN-?,though with few fluctuation between d3 and d14.It could be concluded that dietary supplementation of resveratrol was effective in partially alleviating the adverse effects ofheat stress on intestinal barrier function in yellow-feather broilers by restoring the impaired villus-crypt structure,altering the mRNA expression of intestinal HSPs,mucins,sIgA and tight junctions-related gene,and inhibiting secretion of pro-inflammation cytokines.4 iTRAQ-based identification of differentially expressed proteins related to heat stress in spleen of yellow-feather broilers ITRAQ proteomics identified 62 differentially expressed proteins in the spleen of yellow-feather broiler after 3 days heat stress,including 6 upregulated proteins and 56 downregulated proteins.GO analysis showed that upregulated differentially proteins significantly enriched cellular protein function in cellular component.Additionally,downregulated proteins are significantly enriched in biological process,such as cellular process and cell component,including cell part,membrane part,organelle and organelle part.Combined with KEGG analysis,the following pathways may occur to cope with heat stress in yellow-feather broilers: 1)ferroptosis induced by iron-depended oxidative pathways;2)cell cycle arrest occurs through the P53 signaling pathway,which reduces the synthesis of ribosomes and related proteins;3)upregulated the expression of HSP70,regulated the innate immune pattern recognition receptors of cells and induced inflammatory responses.5 Regulation of resveratrol supplementation on innate immunity in spleen of yellow-feather broilers under heat stress based on the informations of proteomicsThe results showed heat stress caused activation of innate immunity via increased(P<0.05)the mRNA expression of HSP70,TLR1,TLR4,TLR5,MyD88,NOD1,Dectin-1 and transforming growth factor-?-activated kinase 1(TAK1),but decreased the mRNA expression of TLR2,and activated NF-?B,MAPK and PI3K/AKT signaling pathways,as well as increased(P < 0.05)the mRNA expression of interleukin(IL)-1,IL-4,IL-6 and tumor necrosis factor(TNF)-?,but decreased the mRNA expression of interferon(IFN)-?.Dietary supplementation with 500 mg/kg resveratrol reduced(P < 0.05)the mRNA expression of HSP70,TLR4,TLR5,NOD1,Dectin-1 and TAK1,and inhibited the NF-?B,MAPK and PI3K/AKT signaling pathway via down-regulated the protein overexpression of p65,p38 MAPK,and phosphorylation of p65,extracellular signal-regulated kinases 1/2,c-Jun N-terminal protein kinase and AKT,as well as decreased the inflammatory cytokines,including IL-1,IL-4,IL-6 and TNF-? in the spleen under heat stress.Collectively,dietary resveratrol could have beneficial effects to regulate innate immunity and inflammationresponse,inhibit the activation of NF-?B,MAPK and PI3K/AKT signaling pathways induced by heat stress in the spleen.In conclusion,heat stress caused the abnormality of blood biochemical indexes,destroyed the intestinal barrier function,induced the inflammation,and reduced the growth performance of yellow-feather broilers.Resveratrol could effectively improve the metabolism of the body,improved the intestinal tight-junction,inhibited heat stress-induced high-activated innate immunity PRRs and also inflammation response via inhibited the activation of NF-?B,MAPK and PI3K/AKT signaling pathways,alleviated the heat-stressed damage in spleen,benefit to growth performance of broilers. |
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