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1、VitaminEandstressresponseStress(stress)referstothesumofnonspecificresponsetoexternalorinternalverystimuli,causedbystressfactorsknownasstressfactorsorstressors(stressor).Themobilizationofbodytissuesandorganstodealwith,toadapttotheseriesofresponsestostressstimulishowedthatgeneralad
2、aptationsyndrome(GAS).Itisorganizedasfollows:①thephysiologicalchangesofadrenocorticotropichormone(ACTH)productionandincreasedreleaseof,anteriorpituitaryenlargement.②adrenalhyperplasiaenlargement.③duetoincreasedreleaseofcorticosteroneandadrenalcholesterolsecretiondecreased.④poultr
3、eactionaremostsensitivetotissuelymph,thymus,bursaofFabriciusandspleenatrophy;adultchickenbecauseoftheinfluenceofgonadalsteroids,onlythebursalatrophy.Thewhitebloodcellchanges,showedlymphopenia,heterophilsincreased.Increasethebloodconcentrationofcitricacid.Thegrowthretardation,decr
4、easedbodyweight.Themodernintensivelivestockproduction,automation,inordertomaximizetheleveloflivestockandpoultryproduction,increaseeconomicefficiency,tolivestockandpoultryas"productionmachine".Theproductionprocessandtechnicalmeasuresadoptedareoftencontrarytotheanimal'sphysiologica
5、lneeds.Theresultingstressleadstodecreaseofslowgrowth,reducedfecundity,productivityandproductqualityvariation,theimmunityoflivestockandpoultry,causinggreatharmtolivestockandpoultryproduction.Inthemodernindustryproduction,vaccinesfortheprevention,controlanderadicationofinfectiousdi
6、seasesoflivestockplayanextremelyimportantrole,immunizationhandtoprotectthebodyagainstanimalpathogens,ontheotherhand,asakindofspecialstressfactorresultinginimmunologicalstress,somedamagetothebody,thedamageisnotonlyaffectthegrowthanddevelopmentandtheproductionperformanceoflivestock
7、andpoultry,andmaycauseafewanimaldeath.1,thestressresponsemechanismThemechanismofstressresponseisacomplexprocess,accordingtotheCanadianpathologistHansSelyestresstheory,fromthestressstateofview,canbedividedintothreeperiods:alertperiod(emergencyreactionstage),resistance(resistancest
8、age)andfailurestage(exhaustionstage).The
