Rev Colomb Cienc Pecu 2018; 31(3):223-228

Revista Colombiana de Ciencias Pecuarias

Original articles

223

Short Communications

Efficacy of three sealing methods on hatchability of micro-cracked eggs from broiler breeder hens¤

Eficacia de tres métodos de sellado de huevos con micro grietas sobre la incubabilidad de gallinas reproductoras de pollos de engorde

Eficácia de três metodos de selagem de microfissuras em ovos na incubadora provenientes de galinhas reprodutoras de frangos de corte

Jafar Gholami1, MSc; Alireza Seidavi1*, PhD; Mirco Corazzin2, PhD.

1Department of Animal Science, Rasht Branch, Islamic Azad University, Rasht, Iran.

2Department of Agricultural, Food, Environmental and Animal Sciences, University of Udine, Udine, Italy.

(Received: December 27, 2016; accepted: October 31, 2017)

doi: 10.17533/udea.rccp.v31n3a07

¤ Tocitethisarticle:GholamiJ,SeidaviA,CorazzinM.Efficacyofthreesealingmethodsonhatchabilityofmicro-crackedeggsfrombroilerbreederhens.RevColombCiencPecu2018;31(3):223-228.

* Correspondingauthor:AlirezaSeidavi.DepartmentofAnimalScience,RashtBranch,IslamicAzadUniversity,Rasht418574399,Iran.Tel.:+989113313073.E-mail:alirezaseidavi@iaurasht.ac.ir

Abstract

Background: Shellfragilityofhatchingeggscanhavenegativeimplicationsontheeconomicperformanceofhatcheries.Objective:Todeterminetheefficacyofsealingeggshellmicrocrackswitheithercolouredoruncolourednailvarnish,andmoltenparaffinonhatchability,embryonicmortality(EM)andhatchedchickweight(CW).Methods:Eggs(n=576)withmicro-crackswereassignedamongfourgroups(n=144eachgroup)fora21dincubationperiod.Onegroupwasuntreated(CE).Intheothergroups,themicrocrackedareaofeggshellswassealedwithuncolorednailvarnish(NV),colorednailvarnish(CV),ormoltenparaffinwax(MP).Apositivecontrolgroupofun-crackedeggs(UE)wasalsoincluded(n=144).Results:Theeggshellsealanttreatmentsallowednormalconductancerelatedtoeggweightlossafter18dofincubation(11.45%),andchickweightswerenormalamongtreatmentgroups(44.7g).HatchabilityandembryonicmortalityintheearlyandlateincubationperiodsoftheNVgroupwassimilartoUE(84.02vs86.11%forhatchability,6.95vs10.42%forEMondays1-10,and2.08vs1.39%forEMondays18-21respectively;p>0.05).TheCVgrouphadlowerhatchabilitythantheNV(77.77vs84.02%respectively;p<0.05),whereasMPshowedsimilarhatchabilitycomparedtotheCEgroup(59.72vs72.92%,respectivelyp>0.05).Conclusions:Applicationofuncolourednailvarnishonshellmicro-cracksimprovesegghatchability.

Keywords: Eggshell, embryonic mortality, hatching, incubation, micro fissure repairing, poultry.

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Resumen

Antecedentes:laroturadelacáscaraesunproblemaqueafectaaloshuevosparaincubación,reduciendolaeficienciaeconómicadelaproducción.Objetivo:determinarlaeficaciadelselladodemicrogrietasdehuevosutilizandoparafinafundida,esmaltedeuñastransparente,oesmaltedecolorsobrelaincubabilidad,mortalidadembrionaria(EM)ypesodelospollitos(CW).Métodos:loshuevos(n=576)conmicrofisurasfueronasignadosaunodecuatrogruposduranteunperíododeincubaciónde21días.Ungruposemantuvosintratar(CE),enlosotrosgrupossesellóeláreamicro-agrietadadelacascaraconesmalteincolorodeuñas(NV),esmaltedecolor(CV),oparafinafundida(MP).Tambienseincluyóungrupodehuevosnoagrietados(UE,n=144).Resultados: lostrestratamientosaplicadosalacascarapermitieronobtenerunapérdidadepesonormaldeloshuevosa18d(11,45%),asicomounpesonormaldelospollitos(44,7g).ElgrupoNVpresentóincubabilidadyEMsimilaresaUEduranteelperiododeincubación(84,02vs86,11%incubalidady6,95vs10,42%EMentrelosdías1-10;y2,08vs1,39%EMentrelosdías18-21respectivamente;p>0,05).ElgrupoCVtuvoincubabilidadinferioraladeNV(77,77vs84,02%respectivamente;p<0,05),mientrasqueelgrupoMPmostróincubabilidadsimilaralaobtenidaporelgrupoCE(59,72vs72,92%,respectivamentep>0,05).Conclusiones:laaplicacióndeesmalteincolorodeuñasenlasmicro-grietasdelacascaramejoralaincubabilidaddeloshuevos.

Palabras clave: cascara de huevo, eclosión, incubación, mortalidad embrionaria, producción avícola, reparación de micro fisuras.

Resumo

Antecedentes:aquebradacascadoovoéumdosproblemasmaisimportantesduranteaincubação,reduzindoaeficiênciaeconómicadaprodução.Objetivo: determinaraeficáciadaselagemdemicrofissurasnacascadeovocomvernizdeunhas,transparenteoucolorido,eparafinafundidanaeclosão,mortalidadeembrionária(EM),epesodospintosaonascimento(CW). Métodos: ovos(n=576)apresentandomicrofissurasforamdivididosemquatrogrupos(n=144)ecolocadosaincubarporumperíodode21dias.Umdosgruposnãofoitratado(CE).Osovosdosrestantesgruposforamseladoscomvernizdeunhastransparente(NV),vernizdeunhascolorido(CV)ouparafinafundida(MP).Foiaindaincluidoumcontrolopositivoconstituídoporovossemmicrofissuras(UE)(n=144). Resultados: emtodososgrupostratados,observou-seumaperdadepesonormalapós18diasdeincubação(11,45%)assimcomoumpesovivonormaldospintosaonascimento(44,7g).Observou-seumataxadeeclosãoemortalidadeembrionáriasimilardosperíodosiniciaisefinaisdeincubaçãoentreosgruposNVeUE(84,02vs86,11%paraeclodibilidade,6,95vs10,42%paraEMentreosdias1-10,e2,08vs1,39%paraEMentreosdias18-21respectivamente;p>0,05).OgrupoCVevidenciouumataxadeeclosãomenordoqueadogrupoNV(77,77vs84,02%respectivamente;p<0,05).Noentanto,ogrupoMPapresentouumaeclodibilidadesimilaràobservadanogrupoCE(59,72vs72,92%,respectivamentep>0,05). Conclusões:ousodevernizdeunhastransparenteéummétodoapropriadoparaincrementaraeclodibilidadedeovoscommicrofissuras.

Palavras-Chave: casca de ovo, incubação, mortalidade embrionária, produção de aves, reparação de fissuras, taxa de eclosão.

Introduction

Worldproductionofeggsincreasedby23%from2004to2013.Thisincreaseinvolvedmanyoftheleastdevelopedcountries(+68%increasedeggproduction)(FAO,2016).Consideringthateggsareanimportantandrelativelyinexpensivesourceofprotein,vitaminsandminerals,andthattheworldpopulationisrapidlygrowing(Oluwafemiet al.,2015;FAO,2016)furtherincrease of eggproduction canbe expected in thecomingyears.

Crackedeggsisoneofthemostimportantproblemsdecreasing the economic efficiency of producers

(Mazzuco andBertechini, 2014).Kingori (2012)reviewedthatmorethan5%ofeggsarenotavailablefor consumers, and0.5-6%have eggshell damage.AccordingtoNarahariet al.(2000),abouthalfoftheeggsrejectedforshelldefectsshowsmicro-cracks,while the eggshellmembrane remainsundamaged.Withregardtohatching,damagedeggshellaltersthewaterbalanceandgasexchangebetweentheembryoandtheenvironment,favouringbacterialpenetration(Solomon,2010).Littleinformationisavailableonthehatchabilityof eggswithmicro-cracks and thesubsequenthealthofchicks(MoosanezhadKhabisiet al.,2012).Inacomparisonofmicrocrackedeggswithnormaleggs,Barnettet al. (2004)observeda

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32% reductionof hatchability and increased chickmortalityassociatedwithmicrocrackedeggshells.

A potentialmethod for improving hatchabilityconsists in sealing the eggshellswith substancesthat reduce the impact ofmicro-crackson embryodevelopment.Tothispurpose,Narahariet al.(2000)proposedtheuseofadhesiveresin,cellophanetape,andinsulationtape.

We hypothesised that sealing micro-crackson eggshells (which retain undamaged eggshellmembranes) using nail varnish ormolten paraffinmight improve hatchability.Additionally, colourednailvarnishshouldbetestedforapossiblenegativeimpactofcolouradditivesonembryonicdevelopment,embryonicmortality (EM) andhatchingweight ofthe chick (CW).Therefore, the aim of this studywas to determine the efficacy of sealing eggshellmicrocrackswitheithercolouredoruncolourednailvarnishormoltenparaffinonhatchability,embryonicmortality(EM)andhatchedchickweight(CW).

Materials and Methods

Ethical considerations

Thestudywasconductedinagreementwiththerules set by theAnimalEthicsCommittee of theIslamicAzadUniversity,RashtBranch,Iran,andwithDirective2010/63/EU.

Experimental design and treatments

Sevenhundred and twenty (720) eggs (144un-crackedeggs,UE;and576eggswithmicro-cracks)fromRoss308broilerbreeder layers (48weeksold)wereindividuallyweighted.Broilerbreederhenswereimmunizedagainstencephalomyelitis,EDS,salmonella,andGambaro.Eggs(n=576)withmicro-cracksontheeggshell,butwithundamagedeggshellmembranes,weredistributedamongfourgroups(n=144ineachgroup)fora21d incubationperiod.Groupswerebalancedfortheproportionandlocationofmicro-cracksontheeggshell.Group1 remaineduntreated (CE)andwasusedasanegativecontrol.InGroup2,micro-crackedareasweresealedwithuncolorednailvarnish(NV).InGroup3,micro-crackedareasweresealedwithcolored

nailvarnish (CV). InGroup4,micro-crackedareasweresealedwithmoltenparaffin(MP).InGroup5,un-crackedeggs(UE)servedasapositivecontrol.Withineachexperimentalgroup,eggswereassignedrandomlytofoursettertraysandplacedonhatchertrayswithineachgroupattransfer.

Incubator management and measurements

After sealing, eggswere incubated for21d inacommercialincubator(JameswayHatcheryCompanyInc.PS500Multi-StageController,Toronto,CA).Theincubationconditionswere:37.7°Cand70-75%relativehumidityfromd1tod18ofincubation.Onthe18th d ofincubation,theeggsweretransferredintoahatcher(JameswayHatcheryCompanyInc.PS500Multi-StageController,Toronto,CA)and incubatedat36.7 °Cand75-82%relativehumidity fromd19 tod20ofincubation.Onthe21stdofincubation,thetemperaturewasdecreasedhourlyfrom36.7to36.1ºC.

Eggswerecandledandembryonicmortality(EM)recordedon the10thdof incubation,during transfertothehatcher,andattheendoftheincubationperiod.Duringtransfer to thehatcher,eggweight(EW)wasalsorecorded,andweightlosswascalculatedas:EWattransfer/initialEW×100.Thenumberofcontaminatedandpippingeggswererecordedduringtheincubationperiod.Aftercompletinghatching,individualchickbodyweight,numberhatched,dehydratedandculledchickswererecorded,andchickweight/eggweightratiowascalculated.Numberofchickswithredhocksandblackcordwas recordedandexpressedasapercentageofviablechicks,whilehatchability,EM,andcullchickswereexpressedasapercentageofthenumberofeggsset.

Statistical analyses

ThestatisticalanalysiswasperformedusingtheStatistical Package for theSocial Sciences (SPSS,2008),andtheRsoftware(Rcoreteam,2015).Thenormality of data distribution andhomogeneity ofvariancewere tested using the Shapiro-Wilk andLevene tests, respectively.The hatcher traywasconsideredtheexperimentalunit.Aone-wayANOVAwasusedtodeterminetheeffectsoftreatment(UE,CE,NV, CV,MP) on variables.WhenANOVAassumptionswereviolated,robustone-wayANOVAwasconducted,andalsoarobustposthoctestwas

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appliedusingtheWRS2package(Mairet al.,2016).Formultiple comparisons,Bonferroni adjustmentsweremade.Dataispresentedasmean±SEM.

Results

InitialEWwassimilaramongexperimentalgroups(65.40±0.22;p=0.464;datanotshown).ComparedtoUE, non-treatedCE showed lowerweight andhigherweight loss(p<0.05)at18thdof incubation(Table1).Allthreeeggshelltreatments(NV,NP,andMP)hadsimilarEW,EWlossattransfer,andCWathatchcomparedtoUE(p>0.05;Table1).Regardinghatchability, only theNV group showed similarhatchabilitycomparedwiththatofUE(p>0.05).TheMP eggshell treatment had hatchability similar tonon-treatedCE(p>0.05;Table1).ChickweightandCW/EWratiowerelower(p<0.05)forthenegativecontrol(CE)comparedwiththepositivecontrol(UE)athatch(Table1).ChickweightsandCW/EWratiosweresimilaramongUEandNV,CV,andMPgroups(p>0.05;Table1).

Theearlyincubationperiod(d1to10)presentedthe highest EM (Table 2).Moreover, early EM

Table 1. Effect of three eggshell micro-crack sealing methods [uncolored nail varnish (NV), colored nail varnish (CV), molten paraffin (MP)] on egg weight (EW) at transfer, EW loss, hatchability, chick weight (CW) and CW/EW ratio. Data are expressed as mean ± standard error (n = 20).

Trait Uncracked eggs Non-sealed cracked eggs NV CV MP p-value

EW at transfer (g) 59.2±0.41a 55.6±0.17b 57.9±0.33a 58.3±0.36a 58.1±0.18a <0.001

EW loss at transfer (%) 9.62±0.26a 14.66±0.49b 11.74±0.65a 11.56±0.57a 11.05±0.72a <0.001

Hatchability (%) 86.11±1.13a 72.92±4.30bc 84.02±2.08a 77.77±0b 59.72±6.46c 0.002

CW (g) 45.2±0.32a 43.4±0.29b 44.6±0.24ab 44.6±0.50ab 45.0±0.26ab 0.019

CW/EW (%) 68.92±0.32ac 66.61±0.29b 67.97±0.54abc 67.63±0.53ab 69.87±0.43c 0.001

Means with different superscript letters (a, b, c, d) within the same row differ (p<0.05).

was greater (p<0.05) in the negative control (CE)comparedwiththepositivecontrol(UE)(Table2).Withinthetreatedgroups,NVpresentedthelowestearlyEM(Table2).However,MPandNVgroupshadhighermidEM(fromd11tod17dofincubation)thantheUEgroup(p<0.05;Table2).AlthoughthelowestmidEMwasfoundintheUEgroup,themidEMdidnotdiffer (p>0.05) amongeggshell treatedgroups.NosignificantdifferenceswerefoundforEMamongUE,CE,NVandCVduringthehatchperiod(fromd18tod21ofincubation),butEMintheMPgroupwashighercomparedwithallothergroups(p<0.05).ContaminatedeggswereonlyfoundinCV(n=4)andMP(n=14)groups(datanotshown).Thepercentageofcullchickswassimilaramongexperimentalgroups(p>0.05;Table2).OnlyonepippedeggwasnotedintheMPgroup(datanotshown).ChickswithsignsofdehydrationwereonlyfoundintheCE(n=9)andintheMPgroup(n=2;datanotshown).Thepercentageofchickswith redhockand/orblackcordwas thelowest inUE,NVandCVgroups (p<0.05),whiletheMPgrouppresentedanintermediatepercentageofredhockand/orblackcordcomparedwiththelowandhighextremesinUEandCEgroups,respectively(Table2).

Table 2. Effect of three eggshell micro-crack sealing methods [uncolored nail varnish (NV), colored nail varnish (CV), molten paraffin (MP)] on embryonic mortality (EM) and chick traits. Data are expressed as mean ± standard error (n = 20).

Trait Uncracked eggs Non-sealed cracked eggs NV CV MP p-valueEM 1-10d (%) 10.42±1.33ab 16.57±1.13c 6.95±1.79a 13.20±0.69b 15.97±2.86bc 0.048EM 11-17d (%) 0.69±0.69a 7.64±2.86b 4.17±0.80b 2.08±1.33ab 4.17±0.80b 0.059EM 18-21d (%) 1.39±0.80a 1.39±0.80a 2.08±0.69a 2.08±0.69a 6.94±1.39b <0.001Cull (%) 1.39±0.80 1.39±1.39 2.78±1.13 2.08±0.69 2.78±1.13 0.701RHBC (%) 0.83±0.83a 11.59±1.67c 1.64±0.95ab 0±0a 5.82±0.85b <0.001

RHBC = chick with red hock and/or black cord.Means with different superscript letters (a, b, c) within the same row differ (p<0.05).

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Discussion

TheaverageinitialEWwassimilartothatsuggestedbyRoss (2016;65.1g), asaperformanceobjectiveofRoss308hens at44weeksof age.Theaverageweight lossofeggsat transfer,11.45±0.35%,wasconsistentwith the 12% recommended byRoss(2009). No differences among UE and treatedeggshell groupswere found regarding initialEW.Thus,allthesealedeggsshowednormalweight,andnormalconductanceweightlossduringincubation.ConsideringthattheCEgrouphadhigherEWloss,itcanbehypothesisedthatNV,CV,andMPwereabletocontroltheevaporativewaterlosseswithinanormalrange,suggestingthatthesealedsurfacewasnotwideenoughtoaffectnormalwatervapourconductance.TheseresultsappeartobereflectedinCW.Traldiet al. (2011) explained thatCW is highly influenced byeggweight.OurfindingsareincloseagreementwithNarahariet al.(2000),whoapplieddifferenteggshelltreatments (synthetic adhesive resin, cellophaneorinsulationtape)tocrackedeggs.TheCW/EWratiowassimilaramongthepositivecontrol(UE)andNV,CVandMPgroups;andtheaveragevalue(68.49±0.40)wasinlinewiththeproportion(67%)proposedbyRoss (2009).TheUEaveragehatchabilitywascomparabletothatrecommendedbyRoss(2016)asaperformanceobjective(88.6%)ofRoss308hensaround44weeksofage.ItisimportanttonotethatonlytheNVgroupshowedsimilarhatchabilitytothepositivecontrol,whileMPhatchabilitywassimilartotheCEgroup.LowerhatchabilityinCEeggsarelikely due to a gas-exchange reduction and/oraltered humidity conditions, or also to increasedbacterialcontamination.ConsideringtheEWresultspreviouslydiscussed,itmightbehypothesisedthathatching reductionwasmainly due to increasedbacterial penetration in eggs.The highest level ofcontaminationandhighearlyEMfoundintheMPgroupseemstosupportthishypothesis.Barnettet al. (2004) reported that the embryo canwithstand arelativelywiderangeofhumidityinthefirstphasesofdevelopment.However,areductionofgasandwaterconductanceintheMPgroupcannotbeprecluded.Indeed,MPshowednumericallyhigherchickswithredhockandblackcord(stringnavalassociatedwithtemperaturevariationswithintheincubation/hatchingcabinets)thanNV,CVandUE.Moreover,redhockis due to protractedpushon the eggshell (Wilson,

2004),whichmightresult inanincreaseofcarbondioxideconcentrationand/ordecreasedmoisturelossinsidetheegg(Visschedijk,1968;VandeVenet al., 2011).GulcihanSimsek andGurses (2009) sealedhairlinecrackedeggwithnailpolishandreportedthathatchabilitywasreducedby24.9%comparedtointacteggshells,whichhadhigherhatchabilitycomparedtocrackedeggshells.GulcihanSimsekandGurses(2009) explain that these differencesweremainlyduetolateEM(fromd18tod21ofincubation),andthat nail polishwasnot dangerous for the embryodevelopment. It isnotstated in theirarticle if theyusedcoloredoruncolorednailpolish.TheinfluenceofearlyEM(fromd1tod10ofincubation)hasaneffectonhatchability. Jull andLee (2011)explained thatearlyincubationisacriticalperiodduetoimportantevents associatedwith organogenesis.Conversely,inthelateincubationperiod(fromd18tod21)onlytheMPgroupshowedEMhigherthanthepositivecontrolgroup.Thiscouldbedueto thehigherandmoreprotractedbacterial contamination in theMPgroup,inagreementwithGulcihanSimsekandGurses(2009).Nascimentoet al.(1992)showedthatbacterialpenetrationisnotrelatedtoeggshellporenumbers,andcouldbeindependentfromchangesingasandwater conductance of the embryo.Our results aregenerally in agreementwith the studyofNarahariet al.(2000),whoreducedEMbycoveringeggshellcrackswitheitherresin,cellophaneorinsulationtape.

In conclusion, sealingmicro-cracked eggshellswithNVorCVareeffectivetonumericallyimprovehatchability, and to reduceEM inmicro-crackedeggs.Improvedhatchability(15.2%)wasfoundwhenmicro-crackedeggshellsweresealedwithuncoloredvarnish, which seems to facilitate embryonicdevelopmentsimilartoun-crackedeggs.

Acknowledgments

Financial support fromRashtBranch, IslamicAzadUniversity,grantnumber4.5830isgratefullyacknowledged.

Conflict of interest

Theauthorsdeclaretheyhavenoconflictsofinterestwithregardtotheworkpresentedinthisreport.

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