Module_3_Physiological_measures_of_welfare_1

Physiologicalmeasuresofanimalwelfare(1):AutonomicNervousSystemModule3Thismodulewillenableyouto•Understandtherelationshipbetweenwelfareandphysiology•Examinehowtheautonomicsystem(ANS)isassociatedwithchangesinwelfare•UnderstandhowmeasurementofANSresponsescanbeusedtoassesswelfare•IdentifysomeprosandconsofusingANSmeasurestoassesswelfare“Animalwelfareisthephysicalandpsychologicalstateofananimalasregardsitsattempttocopewithitsenvironment”ProfessorDonaldMBroomUniversityofCambridge,UKDefinitionofanimalwelfare(physicalstatus)Changeinwelfare=Changeinphysical&psychologicalstates=PhysiologicalresponsesTypesofresponseAutonomicnervousresponsesNeuroendocrineresponsesChangeinwelfareActivationofCNSAutonomicNervousSystem(ANS)Sympatheticadrenalmedullarysystem(SAM)Parasympatheticnervoussystem(PNS)SAMprocessAdrenalmedullaHeart;metabolism;etcCatecholaminesinnervationcirculationStimulusofCNSPrincipalSAMeffects•Increasedcardiacoutput:–Tachycardia–Increasedcardiacmusclecontraction•Increasedflowofbloodtomuscles:–Peripheralvasoconstriction–Contractionofthespleen•Increasedairintake–Increasedrespiratoryrate&bronchiolerelaxationParasympatheticNervousSystem•RegulatesSAMsystem•Reducescardiacoutput–Bradycardiaviaeffectonsino-atrialnodeUsingtheANStoassesswelfare•ANSresponse=acutemeasure•Pathologicalchanges=chronicmeasure•Directmeasures:–Heartrate–Bloodpressure–Respiratoryrate–CatecholaminelevelsUsingtheANStoassesswelfare•Indirectmeasures:–Adrenalhabituation–(Adrenalenzymes)Measurementtechniquesandtheirdrawbacks•Implanteddevices–Invasiveness•Hands-onmeasurement–Restriction–Disturbance(i)HeartratemeasurementMethodInvasiveRestrictiveDisturbingDirecte.g.stethoscopeTetherede.g.polarmonitorTelemetryRemoteHeartrateIndicateswelfareatthatpointintimeChangeinwelfareH.R.Tachycardia(Activeresponse)H.R.Bradycardia(Passiveresponse)Heartrateincrease•Sheepheartrateincreasedonexposureto:–Strangeperson(increaseof45beatsperminute)–Strangepersonanddog(increaseof79bpm)(Baldock&Sibley,1990)Heartratedecrease•Humans—fainting•Rodents,whendisturbedbythreateningvisualcueorsuddennoise(Hofer1970)Heartarrhythmias•Indicatorofchronicwelfarechanges•Repeatedrestraintcausedtachycardiacarrhythmiasinsquirrelmonkeys(Corleyetal.,1973)•Repeatednoiseandthreateningstimulicausedbradycardiacarrhythmiasinrats(Hofer,1970)(ii)BloodpressuremeasurementMethodInvasiveRestrictiveDisturbingCuff:Tail,ear&armCatheterisation:ArterialTelemetry+/-Bloodpressure•Measureofchronicwelfarechange•Changeinwelfarealtersbloodpressure–Aggressionincreasedbloodpressureinmice(Henryetal.,1975)–Dailyimmobilisationincreasedbloodpressureinrats(Lamprechtetal.,1973)(iii)Respiratoryrate•Assessmentofpresentstate•Easytoobserve•Closelycorrelatedwithheartrate•Lambrespiratoryratefollowing:–Taildocking–Castration(Mellor&Murray,1989)(iv)Catecholaminemeasurement•RapidsamplingrequiredMethodInvasiveDisturbingRestrictiveVariableCatheterisationUrineAutopsy•Analysis:HighperformanceliquidchromatographyCatecholamines•Theadrenalmedullareleases:–Adrenalineisassociatewithpsychologicalstimuli–Noradrenalineisassociatedwithphysicalstimuli•Veryacutemeasures–Immediaterelease(Rat:1-2seconds)–Shorthalf-life(Rat:70seconds)Catecholamineexamples•Ratcatecholaminelevelswith:–Cagedooropening–Handlingandmovingbetweencages–Restraint(40fold)(Kvetnanskyetal.,1978)•Defeatedmaleguineapigsshowsignificantlyhighercatecholaminelevelscomparedtovictors(Sachser&Lick,1989)Adrenalhabituation•Chronicwelfareassessment•Repeatedproblemleadsto:–catecholaminetothatstimulus(habituation)–catecholaminetootherstimuli(sensitisation)•Assessment:–Assesslevelscontinuously–BeforeandafterstressfulperiodAdrenalhabituation:example•Repeatedrestraintofrats•Day27comparedtoday1–Restraintinducedcatecholamineproduction–Differentstressorinducedcatecholamineproduction(Konarskaetal.,1989)LimitationsofANSmeasures•Otherfactorscausingchanges–Activity–Metabolism–Timingofsample•Disturbancecausedbymeasurement–Humanpresence,handling,restraintandsamplingmethod•MeasurementerrorLimitationsofANSmeasures•Individualdifferences-HighandlowrespondersRats(Livezeyetal.,1985)-DominancestatusTreeshrews(vonHolst,1986)-SexRats(Livezeyetal.,1985)Conclusions•ANSresponse=Acutemeasure•Chronicchange=Chronicmeasure•Potentialparameters:–Direct:Heartrate,bloodpressure,respiratoryrateandcatecholamines–Indirect:Adrenalhabituation,enzymes&metabolites•ANSmeasuresarelimited,socareisrequiredintheirassessmentFurtherReading•BALDOCK,N.M.&SIBLEY,R.M.1990Effectsofhandlingandtransportationonheartrateandbehaviourinsheep.AppliedAnimalBehaviourScience28,15-39•CORLEY,K.C.,SHIEL,F.O’M.,MAUCK,H.P.,GREENHOOT,J.1973Electrocardiographicandcardiacmorphologicalchangesassociatedwithenvironmentalstressinsquirrelmonkeys.Psychsom.Medicine35,361-364•HEMSWORTHPH2003:Human-animalinteractionsinlivestockproduction.AppliedAnimalBehaviourScience,81:185-198•HENRY,J.P.,STEPHENS,P.M.&SANTUSTEBAN,G.A.,1975Amodelofpsychosocialhypertensionshowingreversibilityandprogressionofcardiovascularcomplications.Circ.Res.36,