Module_4_Physiological_measures_of_welfare_2

Physiologicalmeasuresofanimalwelfare(2):NeuroendocrineModule4Thismodulewillenableyouto•Understandtherelationshipbetweenwelfareandphysiology•Examinehowtheneuroendocrinesystemisassociatedwithwelfare•Understandhowneuroendocrineresponsescanbeusedtoassesswelfare•Identifysomepros/consofusingneuroendocrinemeasurestoassesswelfareReviewChangeinwelfare=Changeinphysical&psychologicalstates=PhysiologicalresponsesReviewAutonomicnervousresponsesNeuroendocrineresponsesChangeinwelfareActivationofCNSNeuroendocrinesystem•Awelfarechangeaffectsthreesub-divisionsoftheneuroendocrinesystem:–Hypothalamus–Pituitarygland–AdrenalglandHypothalamic-Pituitary-AdrenalAxis(HPA)•Majormediatorofendocrineresponses•HPAincreasesmobilisationofenergystoresforphysicalresponse•HPAmediatesresponsesto:–Stress─Sexualactivity–Courtship─Foodarrival/foragingHPAcascadeAnteriorpituitaryglandCRHAdrenalcortexACTHLiverGlucocorticoidsstimulusHAPvesselscirculationHypothalamusHPAcharacteristics•Responsenotasimmediateassympatheticadreno-medullarysystem•Measureofacutewelfarechanges–Forexample,plasmaglucocorticoidselevatedbetween2-10minutesafterstimulation–CanremainelevatedforhoursdependingonseverityofstimulusGlucocorticoidmeasurementMethodInvasiveRestrictiveDisturbingPlasmaororSalivaUrineFaecesGlucocorticoidmeasurement•Analyticalmethods–Enzyme-linkedimmunosorbentassay–Highperformanceliquidchromatography–Competitiveproteinbindingassay–RadioimmunoassayGlucocorticoids•Corticosterone:rodents,birds•Cortisol:humans,pigs,andmonkeys•UsefuldirectmeasureGlucocorticoidexample1•Cortisolinlambsinresponseto:–Tail-docking–Castration(Mellor&Murray,1989)Glucocorticoidexample2•Urinarycortisolincreasesindomesticdogsiftheyareputinkennels(Hennesseyetal1997)•Ifthedoghasnotbeeninkennelsbefore,theincreaseisgreaterthanifthedoghasexperiencedkennelsbefore(Hiby2005)Chronicwelfareassessment•IndirectassessmentofHPA•Glucocorticoidreceptorsinthebrain–Numberofreceptorsdecreasedinratsthatwereexposedtoprolongedhandlinganddisturbance(Wadham,1997)•ACTHchallengetest–ACTHisadministered,andresultingglucocorticoidlevelsmeasuredACTHchallengetest•Example:Dairycows–Longperiodsofover-crowding=highercortisolresponsethaniflesscrowded(Friendetal.,1977)LimitationstoHPAmeasuresIndividualdifferences:–Earlyexperience(Levineetal.,1967)–Sex(Livezeyetal.,1985)–MetabolismLimitationstoHPAmeasures•Species–NewWorldMonkeys(Klostermannetal.,1986)•Timewhensampled–CircadianrhythmLimitationstoHPAmeasures•Disturbanceduetomeasurement•Humanpresence,handling,restraintandsamplingmethodOtherautonomicmeasuresofanimalwelfare•Bodytemperature•Opioidlevels•OrganpathologyBodytemperature•Acutewelfaremeasure•Changesinotherphysiologicalsystems(e.g.adrenalactivity)=changesincorebodytemperature•Ratbodytemperaturebystormsandunfamiliarpeople(Georgiev,1978)•bodytemperatureindefeatedtreeshrews(vonHolst,1986)TemperaturemeasurementMethodSiteCoreTempInvasiveRestrictiveDisturbingDirect,e.g.thermometerMouth,ear&rectalTelemetryInternal+/-+/-Thermo-imagingSkinOpioids•Threetypes–Endorphins–Enkephalins–Dynorphins•Functions:–Stress-inducedanalgesia–ControlhormonereleaseOpioidmeasurementMethodInvasiveRestrictiveDisturbingBloodBrainreceptorsOpioidexamples•Increaseinplasmaß-endorphininlambsduringcastration,taildockingandmulesing(Shuttetal.,1987)•Tetheredsowshadhigheropioidreceptordensitythangroup-housedsows(Zanellaetal.,1996)OrganPathology•Chronicwelfarechanges=widevarietyofpathologies•Mostaremeasuredpost-morteme.g.,–Adrenalhypertrophy–Kidneylesions–Myocardiallesions•Invivo–StomachulcersPathologyexamples•Socialinstabilityinfemalegroupsofrats=adrenalhypertrophy(Halleretal.,1999)•Subordinatemiceshowkidneylesionsinthepresenceofdominantanimals(Henry&Stephens-Larson,1985)•Myocardiallesionsassociatedwithlongerperiodsofrestraintinpigs(Wutzenetal.,1987)Conclusion•Neuroendocrinesystem=acuteandchronicmeasuresofwelfare•DirectandindirectANSmeasures•Limitationsofmeasures•Otherphysiologicalresponsescanalsobeusedtoassesswelfaree.g.temperature,organpathology,andopioidlevelsFurtherreading•FRIEND,T.H.,POLAN,C.E.,GWAZDAUSKAS,F.C.&HEALD,C.W.,1977:Adrenalglucocorticoidresponsetoexogenousadrenocorticotrophinmediatedbydensityandsocialdisruptionindairycows.J.DiarySci.60,1958-1963•GEORGIEVJ.1978Influenceofenvironmentalconditionsandhandlingontemperaturerhythmoftherat.BiotelemetryPatientMonit.5,229-234•HALLERJ,FUCHSE,HALASZJ&MAKARAGB.1999Defeatisamajorstressorinmaleswhilesocialinstabilityisstressfulmainlyinfemales:Towardsthedevelopmentofasocialstressmodelinfemalerats.BrainResearchBulletin50(1):33-39•HENNESSEYMB,DAVISHN,WILLIAMSMT,MELLOTTC&DOUGLASCW1997Plasmacortisollevelsofdogsatacountyanimalshelter.PhysiolBehav62:485-490Furtherreading•HENRYJP&STEPHENS-LARSONP.1985Specificaspectsofstressondiseaseprocesses.In:MOBERG,G.P.(Ed.)AnimalStress.AmericanPhysiologicalAssociation,Maryland,USA•HIBYEF2005TheWelfareofKennelledDomesticDogs.PhDThesis,UniversityofBristol•KALINNH,CARNESM,BARKSDALECM,SHELTONSE,STEWARTRD&RISCHSC.1985Effectsofacutebehaviouralstresson