Hatchery hygiene evaluation by questionnaire and microbiological screening of hatchery samples

摘要

Questionnaireandmicrobiological-basedsurveyswereconducted,duringtheperiodofMarchtoAugust2011,in5commercialbroilerandlayerhatcherieslocatedinnorthernTanzaniatoevaluatehatcheryhygiene.Informationonfarm/hatcheryhistory,hygienicpracticesandbio-securitymeasuresemployedwascollected.Hatcherysamples(n=59),comprisingdayolddeadchicks(DOC),dead-in-shellembryos(DES)andwalls/premisesswabs(SWB),wereasepticallycollectedfordetailedbacteriologicalscreening.Bothnon-selective(nutrientplateagar),selectiveanddifferentialmedia(MacConkeyagarplate)preparedaccordingtothemanufacturer#8217;sinstructions,wereemployedtodifferentiatebetweenGram-positive,Gram-negativeandlactosefermentingorganisms.CulturepositivecolonieswerecharacterizedfurtherusingTripleSugarIron(TSI)inordertoestablishthepresenceofentericbasedpathogens.nbsp;nbsp;nbsp;Overall,3unitsinKilimanjaroand2unitsinArushawerevisitedandbio-securitymeasuresreportedtobeusedinordertoavoiddiseaseoccurrencewasroutineusageofdisinfectants(n=4;80%),strictentryprohibitionofnon-authorizedpersonnel(n=4;80%),avoidanceofmixingbirdsofdifferentproductionpurposestogether(i.e.layersvizbroilers,n=1;20%)andchangeofclothesaftereachunitoperation(n=1;20%).Themostcitedtargetedareasfordisinfectionwereunitfloor(n=5;100%)andpoultryandhatcherywalls(n=4;80%).Thecoloniesthatgrowontheagarplateswereabout2-4mminsize,irregularandwhitishincolour.StainedcoloniesrevealedthatGramnegativebacteriawerethecommonestmicroorganisms,comprising92%ofallculturepositives.PathogenisolationratewashighestinhatcheryDfollowedbyhatcheriesA,CandBwithnegativeresultsinhatcheryE.TheisolationratewashighestintheDOCandDESderivedsamplesandlowestintheSWBsamples.Characterisationofpositiveculturesamples,usingtheTSIbiochemicaltest,revealedthefollowingproportionsofbacterialagents:Proteusvulgaris(60.7%),Enterobacteraerogenes(42.8%),Enterobactercloacae(17.8%),Salmonellavulgaris(10.7%)andSalmonellatyphi(7.1%).Thehighisolationrateandwiderangeofmicrobialpathogensfoundbythissurvey,revealsaseriousproblemofinadequatebiosecuritypracticeindicatingthatthereisconsiderableroomforimprovementinhatcheryoperationsparticularlywithregardstohygieneandsanitation.Adequatetrainingofhatcheryoperatorsisneededtoraiseawarenessofthecrucialrolehygieneandbiosecurityplaysinensuringhighchickqualityandtheirconsequentsurvivabilityrates.