Exploringcombinedlaboratorytestandslaughterdataforbetter decisionmakingregardingrespiratoryhealthoffinishingpigs
TijsTobias1,3,IreneBisschop1,MartijnBouwknegt2,AnoukVeldhuis1,LucíaDiestePérez1 , IngeSantman-Berends1,GerdienvanSchaik1,3 1RoyalGD,Deventer,TheNetherlands, 2VionFoodGroup,Boxtel,TheNetherlands, 3UtrechtUniversity,FacultyofVeterinaryMedicine,Utrecht,TheNetherlands
Introduction
Extensivediagnosticandslaugtherdatais generatedfromfinishingpigfarms, reflectingdiseaseandproduction. Combiningdatafromvarioussourcesmay supportfarmersdecisionmaking.
Aim:exploretheaddedvalueofcombining slaughterdataanddiagnostictestresults fromfinishingpigfarms.
MethodsandMaterials
Combinedandanonymiseddatafrom47 selectedfarms(fig1.):
Aggregateddata:onerecordperclassper slaughterbatch,includingdate,outcome, explanatoryandfixedparameters.
Outcomeparameters:Continuousdata: (e.g.,averageandvariation(IQR)slaughter weight,meatandbackfatthickness)per record.Countdata:condemnationof organsandcarcassobservations
Explanatoryvariables:Labtestresultsfor InfluenzaAvirus(IAV),PRRSv, Mycoplasmahyopneumoniae(Myo)and Actinobacilluspleuropneumoniae(App) within60daysbeforeslaughter.
Fixedvariables:season,trendovertime, class(sex)andslaughterhouse.
Models:linearregressionmodels,multilevelmixed-effectsnegativebinomial regressionmodels,orKruskal-Wallis equalitytestfortwonon-normally distributedparameters.
Results
•IAV+resultsassociatedwithlower averageandIQRofbackfatthickness. (Fig.2).
•PRRSv+resultsassociatedwithhigher slaughterweightsandmusclethickness, andloweraveragebackfatthickness
•Mhyo+resultsassociatedwithhigher averageandIQRofnetweightand backfatthickness.
•App+resultsassociatedwithaverage bodyweightandIQRandwithbackfat andmusclethickness.
•Nosignificantassociationswerefound betweenPRRSvorIAVswresultsand condemnationdata.
•ForMhyoandAppresults,modelsfor condemnationdatadidnotconverge, llikelyduetoselectionbiasoffarmswith specificrespiratoryhealthstatus
Conclusions
•Labtestresultsforrespiratorypathogens beforeslaughterareassociatedwith slaughterweight,muscleandbackfat measurements.
•Resultsindicatethatlaboratoryresults maybepredictiveforoutcomeat slaughterandprovideopportunitiesto furtherprioritisepreventionand managementofspecificrespiratory diseaseonpigfarms.
Recommendations
•Stakeholderandend-userinterpretations andprioritisations,includingeconomic considerations,arerecommendedfor furtherimplementation,
•Extensiveandmorevariabledata recommendedformodelsevaluationfor organcondemnationdata.
Fig2. Resultsdisplayingsignificant associationsbetweenlaboratoryresultsforrespiratorypathogensandspecificslaughterperformance parameters. Non significant associationsare notshown. Magnitude anddirectionof associationis indicatedbyrelativesizeof + or –indicators. Modelsforcondemnationof lungsor liversdidnotconverge.
Modelsforassociations betweenlabresultsfor InfluenzaandPRRS (antibodies&PCR) providednonsignicant associations
