Diseases Of Dairy Replacement Heifers

http://edis.ifas.ufl.edu/ ( Publisher's URL )
MISSING IMAGE

Material Information

Title:
Diseases Of Dairy Replacement Heifers
Physical Description:
Fact sheet
Creator:
Shearer, J.K.
Publisher:
University of Florida Cooperative Extension Service, Institute of Food and Agriculture Sciences, EDIS
Place of Publication:
Gainesville, Fla.
Publication Date:

Notes

Acquisition:
Collected for University of Florida's Institutional Repository by the UFIR Self-Submittal tool. Submitted by Melanie Mercer.
Publication Status:
Published
General Note:
"originally published as part of Circular 770, reviewed September, 1992,"
General Note:
"DS 78"

Record Information

Source Institution:
University of Florida Institutional Repository
Holding Location:
University of Florida
Rights Management:
All rights reserved by the submitter.
System ID:
IR00004732:00001


This item is only available as the following downloads:


Full Text

PAGE 1

DiseasesofDairyReplacementHeifers1 TheInstituteofFoodandAgriculturalSciencesisanEqualOpportunity/AffirmativeActionEmployerauthorizedtoprovideresearch,educational informationandotherservicesonlytoindividualsandinstitutionsthatfunctionwithoutregardtorace,color,sex,ornationalorigin. FloridaCooperativeExtensionService/InstituteofFoodandAgriculturalSciences/UniversityofFlorida/JohnT.Woeste,DeanJ.K.Shearer2Thediseasesthataccountformostcalfillnesses anddeathsaresepticemia,diarrhea,pneumoniaand parasitism.Theirfrequencyanddistributioninand amongherdsreflectsacomplexinteractionbetween thecalf'simmunedefensemechanisms,environmental influences,andthecapacityofvariousinfectious agentstoproducedisease.Thebestsolutionsfor herdsexperiencingexcessivecalflossliein differentiatingthosemanagementpracticeswhichare beneficialfromthosewhicharedetrimentalorof littlevalueinpromotinghealthandpreventing disease.Forexample,treatmentofallnewborncalves withhyperimmuneserumsorantibioticsiscostlyand ofquestionablevalue.Whilethesemaybeadvised forshort-termproblems,theyarebynomeansagood substituteforenvironmentalsanitationandearly colostrumintake.Antibody-richcolostrumcoupled withthehighlyabsorptivegutofthenewborncalf providesanunparalleledlevelofimmunityto neonataldisease.Today'sprogressivecalfprograms arefoundeduponhealthmanagementpracticeswhich augmentthisnaturalsystemandnotonsystemswhich relyprimarilyontreatmentorvaccinationschemesto controldisease. Thefollowingaresomeofthemorecommon infectiousdiseasesofcalvesfrombirthtoweaning.SEPTICEMICCOLIBACILLOSISSepticemiaisthepresenceofbacteriaandtheir toxins(poisons)inthebloodstream.Itiscausedby awidevarietyofagentsbutwhenitoccursincalves underfivedaysofagethemostprobablecausesare invasivestrainsof E.coli. Thenormalgutofcalvesandotheranimalsis populatedwithmillionsof E.coli whichlive harmoniouslywiththeirhost.Undercertain conditions,however,thisdelicatebalanceisupsetand thedisease-producingstrainsincrease.These organismsandtheirtoxinsmultiply,crossthroughthe intestinalwallandmoveintothebloodstreamwhere theyaredistributedthroughoutthebody.In unsanitarycalvingpens,invasivestrainsof E.coli can alsocausesystemicinfectionbyenteringthroughthe navelofnewborncalves. Calvesaffectedwithsepticemiccolibacillosis becomerapidlydepressedandweak.Diarrheamay occurbutisnotaconsistentfeatureofthisdisease. Mortalityisusuallyhighduetoasevereendotoxic shockinducedbycirculatingbacteriaandtoxinsand calvesmaydiewithin12hoursoftheonsetofclinical symptoms.Deathisoftensosuddenthatitmaybe theonlysignofdiseaseobserved. Calveswhichsurvivetheinitialsepticemic episodesmaysubsequentlydevelopjointinfections; hence,thesyndromeofswolleninflamedjointscaused bynon-fatalcasesofthisdiseaseareknownasjoint ill.Theinfectedjointsarepainfulandbecome arthritic.Severelyaffectedcalvesmaynotmake profitableherdreplacements.Inherdswithahigh incidenceofsepticemia,earlycullingofseverely affectedyoungcalvesmaybenecessary. Septicemiccolibacillosisshouldbesuspectedwhen thereisexcessivemortalityincalvesunderfiveto sevendaysofage.Successfultreatmentdepends uponpromptdiagnosis.However,therapyistheleast effectivewaytodealwiththisdisease.Calves 1.ThisdocumentisFactSheetDS78oftheDairyProductionGuide,originallypublishedaspartofCircular770,reviewedSeptember,1992, FloridaCooperativeExtensionService.Formoreinformation,contactyourcountyCooperativeExtensionServiceoffice. 2.AssociateProfessor,CollegeofVeterinaryMedicine;CooperativeExtensionService,InstituteofFoodandAgriculturalSciences,University ofFlorida,Gainesville.

PAGE 2

DiseasesofDairyReplacementHeifers Page2 deficientincolostralantibodiesaremostsusceptible; dairyfarmerswhodonotemphasizecolostrum managementoftenlosemanycalvestothedisease. Calvesborninaclean,drycalvingareaandgivenan adequateamountofcolostrumsoonafterbirthare lesslikelytosuffersepticemia.Properlydisinfecting thenavelandmovingthecalftoaclean,dry individualpenwillhelpwardoffsepticemia.DIARRHEA(SCOURS)Diarrheaiscommon,ifnotuniversal,incalves underonemonthofage,andcertainlynotallcases demandaggressivetreatment.However,diarrheic calvesshouldbeobservedcloselyuntilstoolsreturnto normalconsistency.Diarrheacanbecausedbya varietyofbacteria,viruses,andprotozoaormayalso resultfromimproperfeedingpracticesasdiscussed under"StartingtheNutritionProgram."The followingdiscussionwillbelimitedtotheinfectious causesofdiarrheainyoungcalves.ENTEROTOXICCOLIBACILLOSISWhilesepticemiaandrapiddeatharethe distinguishingfeaturesofsepticemiccolibacillosis, enterotoxiccolibacillosisischaracterizedbydiarrhea, dehydration,andtoxemiaofvaryingseverity.Itis causedbyenterotoxigenic(intestinaltoxinproducing) strainsof E.coli (ETEC).Theseorganismsdonot enterthebloodstreambutattachthemselvestothe walloftheuppersmallintestinewheretheymultiply andproducelargeamountsofenterotoxin(poison producedintheintestine).Thesetoxinsdrainfluid andelectrolytesfromthebloodandotherbody tissues.Thisresultsinseveredehydrationanda metabolicimbalancethatwillleadtodeathifnot corrected.Enterotoxiccolibacillosisisoneofthemost commonformsofcolibacillosisincalvesunderone weekold.Deathcanoccursuddenlybeforethe developmentofdiarrhea.Mostinfectedcalves developawaterydiarrhea.Thetail,buttocks,and legsofaninfectedcalfwillusuallybestainedor soiledwithdiarrheicmanure.Thesecalvesmay refusetosuck,dependingonthedegreeoftoxemia anddehydration,andmayliedownandrefusetorise astheygrowweaker. Wheneveroutbreaksofdiarrheicdiseasesoccur everyattemptshouldbemadetoisolatetheaffected fromtheunaffectedsusceptiblecalves.Asnewcalves areborntheyshouldbehousedasfarawayas possiblefromsickcalves.Ifpossible,assignseparate workcrewstofeedandcareforeachgroupsothat thecrosscontaminationpotentialcanbeminimized. Separatebucketsorbottlesshouldbeusedforfeeding ratherthanusingthesameforallcalves.Sanitation isamustinthecontrolofdiarrhealdiseases. Provisionstoinsurethatnewborncalvesreceive colostrumareparticularlyimportantforresistanceto thesediseases.Promisingresultshavebeenobtained fromresearchtrialsonimmunizationofthepregnant drycowagainstcolibacillosisincalves.Vaccinationof thecowwithin2-4weeksofcalvingwithvaccines producedfromstrainsofETECstimulatesthe productionofagreaterconcentrationofspecific antibodiesthat,whengivenincolostrumatbirth, providesanextramarginofprotectionagainstETEC. Morerecently,withthedevelopmentofavaccine containingmonoclonalantibodytothepilusantigen ofETEC,problemherdscangetimmediate protectionforcalvesinthefaceofcolibacillosis outbreaks.Thismustbeadministeredassoonas possiblefollowingbirth(withinthefirst8to12hours atleast)andisnoteffectiveasatreatmentforcalves whicharealreadyinfected.Itcanonlypreventthe disease.ROTAANDCORONAVIRUSRotavirusisafrequentcauseofdiarrheaincalves under2weeksofage;coronavirusmoreoftenaffects calvesaged2to4weeks.Asprimarypathogensthese virusesgenerallyinduceonlyamilddiarrhea,but whencombinedwithsecondarybacterialinfections theymaybecomemajorcontributorstomortalityin calvesonemontholdandyounger.Bothviruses occurthroughouttheUnitedStatesandinmany foreigncountries.RecentstudiesintheU.S.indicate thatthesevirusesarepresentinmost,ifnotall,herds andthatthemajorityofcalveseventuallybecome infectedbythem.Thesevirusessurviveinfecesfor longperiods.Afteringestiontheyattackthe epithelialcellsliningthesmallintestine.Thelossof thiscellularbarrierincreasessusceptibilitytoinvasion byotherinfectiousagents.Avaccineagainstthese virusesisavailableforpregnantcowsandnewborn calvesandshouldbeusedwherethevirusesare particularlytroublesome.Somedairymanagershave foundthatfeedingcolostrumcontinuallyforaweek afterbirthreducestheincidenceofseriousdiarrhea causedbytheseviruses.

PAGE 3

DiseasesofDairyReplacementHeifers Page3SALMONELLASalmonellosiscausesatleastthreeclinical syndromesincattle:septicemia,enteritis,and abortion.Septicemicsalmonellosisismostcommon incalves,andtypicallyoccursat3to4weeksofage (septicemiccolibacillosisismorecommonincalves under2weeksofage.).Infectedcalvesbecomeweak andoccasionallyshowsignsofincoordination, suggestinginvolvementofthenervoussystem.The diseasemayendindeathwithin24to48hoursofthe onsetofillness.Thetypicalmortalityrateis25%,but itmayapproach100%. Methodsoftreatmentarecontroversial,but regardlessofthetherapeuticregimenchosen, treatmentmustbeginearlyinthecourseofthe disease.Controlduringoutbreaksrequiresstrict environmentalsanitationandisolationofaffected calves.Calvesshouldbekeptinindividualpens,and feedingutensilsshouldberoutinelydisinfected. Preventionusingvaccinesforsalmonellahaveyielded mixedresultsandcannotbeuniversallyrecommended atpresent.SUDDENDEATHSYNDROME (ENTEROTOXEMIA)Thesuddendeathofanapparentlyhealthycalfis frequentlyduetoenterotoxemiacausedby Clostridiumperfringens.Theseorganismsoccur naturallyinthesoilandmaybefoundinthegutof normalcalves.Undercertainconditions,clostridial organismsmultiplywhileintheintestinaltractand produceapotententerotoxinthatdamagesblood vesselsinthebrainaswellasothertissues.Death usuallyoccurssuddenly. Overfeedingofgrainand/ormilkisonecausefor therapidproliferationofClostridia.Calves consumingconsiderableamountsofgrainwhilestill receivingafullfeedingofmilkaremostlikelyto developthisdisease,thustheincidenceofsudden deathisgenerallyhighestforcalves3to8weeksof age.Sincemostcalvesarefedfreechoiceand feedingerrorsaresometimesmade,drycowsand calvesshouldberoutinelyvaccinatedwithClostridium CandDtoxoid.Fordrycowsbeingvaccinatedfor thefirsttime,twoinjectionsshouldbemade2to3 weeksapart.Forcalves,vaccinationsshouldbemade at1to2weeksofageandrepeatedin2to3weeks.PNEUMONIAINCALVESIncoolclimates,calfpneumoniaisusually associatedwithpoorventilation.InFlorida,however, calfpneumoniaoftenoccursaroundweaningtime whencalvesaremovedfromindividualtogrouppens. Thecomminglingofcalvesintogrouppensincreases thepotentialfortheirexposuretodiseaseorganisms. Problemsarecompoundedbystressassociatedwith peckingorderestablishmentrituals.Consequently, calvesshouldbegroupedaccordingtobreedandbody sizeandgroupsshouldcontainnomorethan10to12 calves. Somedairyfarmersmakethestresstocalves worsewithoutmeaningtobyschedulingvaccination, dehorning,anddewormingprocedurestoocloseto weaningforthesakeofconvenienceorbecauseit mayseemlikethemostappropriatetime.Itis preferabletoperformtheseproceduresatleast1to 2weeksbeforeorafterweaning. Theinfectiousagentswhichmostusuallycause respiratorydiseaseincalvesarethebacteria Pasteurella spp., Corynebacteriumpyogenes ,and Mycoplasma spp.;andseveralvirusesincluding infectiousbovinerhinotracheitis(IBR), parainfluenza-3(PI3),bovinevirusdiarrhea(BVD), andbovinerespiratorysyncitialvirus(BRSV).Calves areexposedtothesepathogensastheyareputinto grouppenswheretheysharefeedandwatering facilities.Calvesaremorelikelytoresistinfectionif weaningstressisminimized.Vaccinatingcowswith IBR/PI3andBVDprotectsnewborncalveswhoare fedcolostrumoffromvaccinatedcows(CAUTION: donotusemodifiedlivevaccinesforIBRandBVD inpregnantcows).TheintranasalIBR/PI3vaccine mayprovidecalvesadditionalimmunitytodisease. Severalrespiratorydiseasecomplexvaccinesarenow beingdeveloped. Pasteurellahemolytica vaccine, whichhasbeendevelopedrecently,mayalsobe helpfulinpreventinginfectionwherethisorganismis amajorcauseofpneumonia.