ContentslistsavailableatScienceDirect
Animal
Feed
Science
and
Technology
journalhomepage:www.elsevier.com/locate/anifeedsci
Short
communication
Comparison
of
total
tract
digestibility
and
nitrogen
balance
between
Cinta
Senese
and
Large
White
pigs
fed
on
different
levels
of
dietary
crude
protein
A.
Acciaioli, F.
Sirtori, L.
Pianaccioli, G.
Campodoni, C.
Pugliese, R.
Bozzi, O.
Franci
∗ DepartmentofAgriculturalBiotechnology,AnimalScienceSection,ViadelleCascine5,50144Firenze,Italya
r
t
i
c
l
e
i
n
f
o
Articlehistory:
Received19November2010 Receivedinrevisedform24May2011 Accepted25May2011 Keywords: CintaSenese Localpig Digestibility Nitrogenbalance Dietaryprotein
a
b
s
t
r
a
c
t
TheworkaimedtostudythedigestivecapacityandnitrogenbalanceofCintaSenesepig
feddietswithdifferentcrudeprotein(CP)content.Twelvecastratedmalepigs(6Cinta
Seneseand6LargeWhite),ofthesamebodyweight(onaverage62.7kg),weresubmitted
to8subsequenttrialsoftotaltractdigestibilityandnitrogenbalance.Thepigswerekeptin
metabolismcagesallowingcollectionoffaecessamplesandtotalurine.Thediets,of
exclu-sivevegetalorigin,wereformulatedtocontainfourproteinlevels70,100,130and160g/kg
asfed(namedCP7,CP10,CP13andCP16,respectively)assuredmainlybysoybeanmeal.
Totaltractnutrientapparentdigestibilitydidnotdiffer(P>0.05)betweenbreeds.Apparent
digestibilityofCPincreased(P<0.01)withincreasingdietaryCP(from0.756to0.874for
CintaSeneseandfrom0.742to0.868forLargeWhite),asconsequenceoffaecalendogenous
nitrogenwhichunderestimatesthedigestibilityofproteinininverseproportionwithits
amountinthediet.Nitrogenbalanceshowedthatbreeddifferences(P<0.01)emergedfor
theurinaryNandthetotalexcretedN,withhigheremissioninCintaSenesethaninLarge
Whitebreed.ThedifferencewasnotsignificantatCP7diet(excretedN:19.4vs.17.1g/d
forCintaSeneseandLargeWhite)butbecameprogressivelymoreimportant(P<0.01)in
thedietswithhigherCPcontent(excretedNatCP16diet:39vs.35.4g/dforCintaSenese
andLargeWhite).Consequently,LargeWhiteretainedmorenitrogenthanCintaSenese
(about+2.6;+3.0;+3.4;+3.8g/dwithCP7;CP10;CP13;CP16diet,respectively;P<0.01).So,
theefficiencyofNutilization(retainedN/absorbedN),favouredtheLargeWhiteinallthe
testeddiets(P<0.01).TheseresultssuggesttolimittheCPcontentindietsforCintaSenese
breed,toreducenitrogenpollutionintheenvironment.
© 2011 Elsevier B.V. All rights reserved.
1. Introduction
Moststudiesonproteinrequirementsinpigswereconductedsincelongtimeinordertooptimizegrowthrateandfeed efficiency,tolimitthecostsandtoreducethenitrogenpollutionintheenvironment.Theresearcheswerecarriedoutonpigs belongingtoimprovedbreedsmodulatingthequantitativeandqualitativecontentofdietaryproteinandaimedatverifying growthandcarcassperformances(Tuitoeketal.,1997;Chenetal.,1999;Kerretal.,2003),atstudyingilealdigestibility
Abbreviations:ADF,aciddetergentfibre;AIA,acidinsolubleash;CP,crudeprotein;CS,CintaSenese;CTTAD,coefficientoftotaltractapparent digestibil-ity;DCP,dietarycrudeprotein;DM,drymatter;LW,LargeWhite;NDF,neutraldetergentfibre;PDO,protecteddesignationorigin;TTAD,totaltractapparent digestibility.
∗ Correspondingauthor.Tel.:+390553288263;fax:+39055321216. E-mailaddress:oreste.franci@unifi.it(O.Franci).
0377-8401/$–seefrontmatter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.anifeedsci.2011.05.009
Table1
Experimentaldesignandsequenceofperiodsofadaptationtodietonfloorandofdigestibilitytrialoncage.
Weekoftrial CintaSenese LargeWhite
Group1(pigs1–3) Group2(pigs4–6) Group1(pigs7–9) Group2(pigs10–12)
1 CageCP10a FloorCP16 CageCP10a FloorCP16
2 FloorCP7 CageCP16 FloorCP7 CageCP16
3 CageCP7 FloorCP13 CageCP7 FloorCP13
4 FloorCP13 CageCP13 FloorCP13 CageCP13
5 CageCP13 FloorCP7 CageCP13 FloorCP7
6 FloorCP16 CageCP7 FloorCP16 CageCP7
7 CageCP16 FloorCP10 CageCP16 FloorCP10
8 CageCP10 CageCP10
Inboldtheperiodsofdigestibilitytrial.
aPrecededbya7-dayperiodonfloorforadaptationtodiet.
ofaminoacids(Fanetal.,1994;Buraczewskaetal.,1999;FanandSauer,2002),atestimatingtotaltractdigestibilityand nitrogenbalance(Bosietal.,1995;LindbergandAndersson,1998;Canhetal.,1998;LeBellegoetal.,2001;Dengetal.,2007). TherecoveryandvalorisationoftheautochthonousMediterraneanpigbreeds,withlowpotentialforleangrowthand highadipogeneticcapacity(Lopez-Bote,1998;Francietal.,2001;Gandinietal.,2001),suggesttheneedofanalogousstudies dedicatedtothem.Actually,fewinformationontheoptimalcontentofdietaryproteinforlocalpigsareavailable.OnIberian pig,studiestestedtheproteinrequirementfrom15to50kg(Nietoetal.,2002)orfrom50to100kgofbodyweight(Barea etal.,2006)andindicatedtheoptimalproteincontentofthedietshouldbe130and95g/kgofDM,until50kgandfrom50 to100kgofbodyweight,respectively.OnCintaSenese,alocalbreedofTuscany,Sirtorietal.(2010)reportedthat100g/kg ofdietaryproteincanbeusedbeyond70kgofbodyweight.Onthecontrary,relevantstudiesondigestibilityandnitrogen balancearescarce:forinstance,Freireetal.(1998)studiedthedigestivecapabilityofnewweanedAlentejanopigletsin comparisonwithLargeWhitewhereasAcciaiolietal.(2003)investigatedthedigestiveutilizationandnitrogenbalanceof fieldbeaninCintaSenesepig,however,noinformationonmodulationofdietaryproteincontentinlocalpigsareavailable. ThisstudyaimedtoquantifythedigestivecapacityandnitrogenutilizationofCintaSenese,themostwidespreadItalian localpig,incomparisonwithLargeWhitebreed,feddietscoveringawiderangeofproteincontent,fromwellinexcessto marginaldeficiency.
2. Materialsandmethods
2.1. Animals,designanddiets
Twelvecastratedmalepigs[6CintaSenese(CS)and6LargeWhite(LW)],ofthesameweightatthestartoftheexperiment (overallmean62.7;s.d.6.1kg)andofdifferentages(CS5months;LW4months),weresubmittedto8subsequenttrials ofdigestibilityandnitrogenbalance,usingmetabolismcages(60cm×130cm)tocollectsamplesoffaecesandtotalurine. Eachcageperiodwasprecededbya7-dayperiodonfloorforadaptationtodietandlasted7days.Trialwascomposedof aphaseofadaptation(3days)andaphaseofcollectionoffaecessamplesandoftotalurine(on4days)accordingtothe methodologyproposedbySchiavonetal.(1996)andinlinewithothertotaltractdigestibilitytrials(Canhetal.,1998;Nieto etal.,2002).Twogroupsofthreeanimalsweresetupforeachbreedandtheywerealternativelyemployedasshownin Table1.So,thesixcageswerecontemporarilyoccupiedbythreesubjectsforeachbreedfedthesamedietandeachanimal receivedalldietarytreatmentsthroughoutthewholeexperiment.Theaverageweightsatentryincagewerenotdifferent betweenbreedsandamongdiets(P>0.05).Theentireexperimentwasconductedaccordingtotheguidelinesonanimal welfareinanimalresearchoftheItalianLegislativedecreeno.116/1992.
Thediets,ofexclusivevegetal origin,wereformulatedtocontainfourproteinlevels: 70,100,130and 160g/kgas fedbasis(namedCP7,CP10,CP13andCP16,respectively).Ingredientsandchemicalcompositionofthedietsasfedare reportedinTable2,whereitisevidentthatproteinwasassuredmainlybysoybeanandnoaminoacidsupplementationwas made,accordingtothecurrentfeedingsystemofCintaSenese,thatoftenrespectstherulesoforganicfarming(European Commission,2008)orof“SuinoCintoToscano”PDOConsortium(INEQ,2007).Dietswerepelletedtoavoidsingleingredients tobeselectedbytheanimals.Animalswerefedtwicedaily.Dailyfeedallowancewas90g/kgofmetabolicweight.Feed allowancewasalwayscompletelyingested.Waterwasprovidedadlibitum.Metabolismcagesweresuppliedwithwater nippleandtroughandallowedtorecovertotalurineinflasksaddedwith20mlof8Nsulphuricacid,toavoidammonialoss (Sardietal.,1998).Thedailyurineproductionofeachsubjectwasweighedandsampled.Samplesoffaecesforeachsubject werecollectedthriceadayinordertocreatetheindividualdailyfaecessample.
UrinewasanalysedfornitrogencontentfollowingKjeldhalmethod.Theanalyticalmethodsusedforfeed,faecesand urinearereportedbyMartillottietal.(1987).Feedandfaecesweresubmittedtoproximateanalysisandtoacidinsoluble ash(AIA)determination.Acidinsolubleashwasusedasundigestibleinternalmarkerinordertocalculatethetotaltract apparentdigestibility(TTAD)ofdietarycomponentsfollowingthemethodproposedbyVanKeulenandYoung(1977).
Table2
Ingredientsandchemicalcompositionofdiets.
Dieta
CP7 CP10 CP13 CP16
Ingredients
Soybeanmeal 120 190 260 340
Straw 50 50 50 50
Sugarbeetpulp 120 110 90 60
Maizestarch 650 590 540 490 Calciumcarbonate 15 15 15 15 Dicalciumphosphate 15 15 15 15 Sodiumchloride 4 4 4 4 Vitamin–mineralpremixb 10 10 10 10 Lignosulphite 16 16 16 16 Composition(g/kgDM) Drymatter 858 875 877 878 CrudeProtein 83 110 153 183 Etherextract 6 6 5 7 NDF 118 123 122 117 ADF 72 75 76 74 Ash 77 80 72 83 Calcium 10.6 10.7 10.8 10.8 Phosphorus 4.3 4.8 5.3 5.8 Lysinec 3.3 5.2 7.2 9.4 Methioninec 0.7 1.1 1.6 2.1 Grossenergyd(Mj/kgDM) 16.89 17.09 17.30 17.50 aCP7,CP10,CP13,CP16=70,100,130,160g/kgofDCP,respectively.
bVitamin–mineralpremixprovidedperkgoffeed:VitaminA:12,000IU;VitaminD3:1800IU;VitaminE:60mg;VitaminK:2mg;VitaminB1:1.5mg;
VitaminB2:4.0mg;VitaminB6:4mg;VitaminB12:0.020mg;Calciumpantothenate:15mg;Folicacid:0.5mg;Biotin:0.2mg;Co:0.80Fe:120mg;I: 0.8mg;Mn:60mg;Cu:20mg;mg;Zn:100mg;Se:0.15mg.
cCalculatedfromtabulateddataofthesoybeanmealalone(AntongiovanniandGualtieri,2002). dCalculatedfromspecificvaluesoftheanalyticalcomponents.
2.2. Statisticalanalysis
DatawereanalysedbyGLMProcedure(SAS,2007)usingthefollowingmodel: Yijkl=+Bi+Sij+bi∗Pk+c∗Xijkl+Eijkl
whereY=lthobservationonjthsubject;B=fixedeffectoftheithbreed(CS,LW);S=fixedeffectofthejthsubjectwithin breed;P=continuouseffectofkthproteincontentofdiet;X=continuouseffectofbodyweightattrialstart;E=randomerror. TheactualCPcontentofthediets(DCP)wasconsideredascontinuouseffectwithineachbreed(intraclassregression). ResultswerereportedasLSmeansalongtheregressionlineforeachbreedatthespecificlevelofDCP(70,100,130and 160g/kg)andsignificanceoflinearregressionwastestedwithineachbreed.ThedifferencesbetweentheLSmeansofthe breedsateachdietwerestatisticallytestedbyStudent’st-test.
3. Results
3.1. Digestibility
Table3reportsindividualfeedandproteinintakesandthecoefficientsofTTAD(CTTAD)forthemajordietarycomponents. Bothdrymatterandcrudeproteinintakesdidnotdiffer(P>0.05)betweenthebreeds,sincethefeedadministrationwas determinedonthebodyweightbasis.AlsotheCTTADofthevariousdietarycomponentswerenotdifferent(P>0.05)between thebreedsforthevariousdiets.AsconcernstheinfluenceofDCPlevelontheTTAD,anevidenteffectwasfoundonlyforCP whosedigestibilityincreasedwithincreasingDCP(P<0.01).
3.2. Nitrogenbalance
Table4showstheresultsofnitrogenbalanceofthedietsonthetwobreeds.Differencesbetweenbreedswerefound neitherforNintake,norforabsorbedandfaecalN.Allthesequantities,however,increasedwiththeDCPcontent(P<0.01), despitetheincreaseoftheTTADofCP(Table3).Onthecontrary,breeddifferences(P<0.01)emergedfortheurinaryNand, consequently,forthetotalexcretedNwithhigheremissioninCintaSenesethaninLargeWhitebreed.Theefficiencyof Nutilization,expressedasapparentbiologicalvalue(retainedN/absorbedN),washigherintheLargeWhiteforalldiets (P<0.01),butitdidnotvaried(P>0.05)withincreasingDCPonbothbreeds.
Table3
FeedintakeandtotaltractdigestibilitiesinCintaSenese(CS)andLargeWhite(LW)pigsofthesamebodyweight(62.7kg)feddietswithincreasingdietary crudeproteincontent.
Breed Dieta LinearregressiononDCP(P) Breedeffect(P) r.s.d.b
CP7 CP10 CP13 CP16 Intake(g/d) Drymatter CS 1728 1737 1745 1754 0.06 0.82 23.43 LW 1724 1736 1749 1761 <0.01 Crudeprotein CS 141 201 260 320 <0.01 0.73 10.40 LW 142 202 261 321 <0.01 Digestibilitycoefficient Drymatter CS 0.869 0.867 0.866 0.864 0.52 0.98 0.012 LW 0.874 0.869 0.864 0.859 0.03 Organicmatter CS 0.902 0.901 0.900 0.900 0.59 0.83 0.01 LW 0.905 0.901 0.898 0.894 0.05 Crudeprotein CS 0.756 0.789 0.832 0.874 <0.01 0.58 0.033 LW 0.742 0.784 0.826 0.868 <0.01 aCP7,CP10,CP13,CP16=70,100,130,160g/kgofDCP,respectively. b Residualstandarddeviation.
Table4
Intake,balanceandefficiencyofutilizationofnitrogenofthedietsinCintaSenese(CS)andLargeWhite(LW)pigsofthesamebodyweight(62.7kg)fed dietswithincreasingdietarycrudeproteincontent.
Breed Dieta LinearregressiononDCP(P) Breedeffect(P) r.s.d.b
CP7 CP10 CP13 CP16 Nintakeg/d CS 22.6 32.2 41.8 51.3 <0.01 0.68 1.7 LW 22.9 32.4 41.9 51.5 <0.01 AbsorbedNg/d CS 16.6 25.9 35.2 44.5 <0.01 0.94 2.2 LW 17.1 26.1 35.1 44.1 <0.01 FaecalNg/d CS 6.0 6.3 6.6 6.8 0.10 0.53 0.9 LW 5.9 6.3 6.8 7.3 <0.01 UrinaryNg/d CS 13.4 19.6f 25.9f 32.2f <0.01 <0.01 2.7 LW 11.3 16.9g 22.4g 28.0g <0.01 TotalexcretedNg/d CS 19.4 25.9f 32.5f 39.0f <0.01 <0.01 2.8 LW 17.1 23.2g 29.3g 35.4g <0.01 RetainedNg/d CS 3.2 6.3f 9.3f 12.3f <0.01 <0.01 2.9 LW 5.8 9.2g 12.7g 16.1g <0.01 ABVc% CS 20.87d 23.29f 25.71f 28.12d 0.12 <0.01 7.77 LW 30.21e 32.46g 34.70g 36.94e 0.14 aCP7,CP10,CP13,CP16=70,100,130,160g/kgofDCP,respectively. b Residualstandarddeviation.
c Apparentbiologicalvalue=retainedN/absorbedN.
d,eBetweenbreedsandwithindiet,meanswithdifferentlettersdiffer(P<0.05). f,gBetweenbreedsandwithindiet,meanswithdifferentlettersdiffer(P<0.01).
4. Discussion
Thecommonbeliefthatthe“rustic”pigcouldhavehigherdigestivecapabilitythantheimprovedoneisnotproved inthepresentworkandrarelyconfirmedintheavailableliterature.ThepresentresultsindicatethatCintaSeneseand LargeWhitebreedsexhibitedthesameapparentdigestivecapabilityforallthedietarycomponentsandforallthetested diets.Differentresultswerefoundinapreviouswork(Acciaiolietal.,2003)whichshowedthatCintaSenesepighadlower digestivecapabilitythanLargeWhite.Thisdiscrepancycanbeduetothefactthatinthelattertrialpigsofthetwobreeds werecoetaneous,whileinthepresentonetheyhadthesameweightandconsequentlyCintaSenesepigs,beingolderthan LargeWhite,couldhaveimprovedtheirdigestiveability.Asconcernsotherlocalpigs,Freireetal.(1998)foundthatnew weanedpigletsofAlentejanobreedhadhigherTTADforsomedietarycomponents(fatandaciddetergentfibre)thanLarge Whiteonesbutthewidedifferenceinagewiththesubjectsofthepresentstudydoesnotallowtodrawacomparison.On theotherhand,Moralesetal.(2002),onbarrowsof88kgofbodyweight,foundhigherapparentdigestibilityfororganic matterinLandracethaninIberianbreedwhereasnodifferencewasfoundforcrudeprotein.
TheresultofthepositiveeffectofDCPcontentontheapparentdigestibilityofCPisinagreementwiththeliterature andcanbeconsideredspurioussincethefaecalendogenousnitrogen,practicallyconstant,affectsproportionallymorethe faeceswithlowerproteincontent.Variousexperimentsdocumentedthispositivecorrelation,bothatilealandtotaltract level(FuruyaandKaji,1989;Fanetal.,1994;Bosietal.,1995;Canhetal.,1998;LeBellegoetal.,2001;Dengetal.,2007), butonlyFanetal.(1994)clearlyjustifiedtheresultasinfluencedbyendogenousCP.
Differencesbetweenthetwobreedswereevidentfornitrogenbalance,particularlyasitconcernstheurinaryNemission thatwashigherinthelocalbreed.Moreover,theselossesweresensitivetotheDCP contentsincethedifferencewas
notsignificantatthelowestDCPcontentandbecameprogressivelymoreimportantinthedietswithhigherCPcontent. Consequently,theLargeWhiteretainedhigherquantitiesofnitrogenthanCintaSenese(about+2.6;+3.0;+3.4;+3.8g/dat CP7,CP10,CP13andCP16,respectively).However,therewasanoticeableincreaseinNretentioninbothbreedsasNintake increased,indicatedbyregressionanalysiswhichneverdeviatedfromlinearity,eveninCintaSenese.ThelowerNutilization ofCintaSenesecomparedtoLargeWhiteisinaccordancewithstudiesbyAcciaiolietal.(2003)andstudiesbyFreireetal. (1998)withAlentejano(anotherlocalbreed)comparedtomoderngenotypepig.
Generally,theprogressiveincreaseofNexcretionasDCPincreasesiswelldocumentedintheliteratureonselectedpigs (Canhetal.,1998;LeBellegoetal.,2001;Dengetal.,2007).ThesestudiesshowedaswellanincreaseofretainedNbutthe trendappearedmoreattenuate,andsometimesnotsignificant,thanthatofthepresenttrial.However,itmustbeconsidered thattherangeofDCPcontentinthoseexperimentswaslesswideandlocatedmoreupward(from123to189g/kg)compared tothepresentstudy.Bosietal.(1995)reportedthaturinaryNinimprovedpigincreasedasdietaryCPincreasedfrom144 to185andsubsequentlyto225g/kg,whileretainedNincreasedfrom144and185g/kgandplateauedafterwards.
CintaSenesebreedwaspenalizedinrespecttoLargeWhiteatalltheDCPcontentalsofortheefficiencyofNutilization (retainedN/absorbedN).However,irrespectiveofthebreeds,thevaluesofthecoefficientsshowedanotsignificanttrend towardtheDCPincrease,inpartialcontrastwiththefindingsofCanhetal.(1998)from125to165g/kgDCPandDengetal. (2007)from136to182g/kgDCP,thatfoundadecreasingtrend.
5. Conclusions
CintaSenese,themostwidespreadItalianlocalpig,hasbeencomparedwiththeLargeWhite,themostknownselected breed,forthedigestivecapacityandnitrogenutilizationusingdietscoveringawiderangeofproteincontent,fromwellin excesstomarginaldeficiency.Thedigestivecapacityofthelocalbreeddidnotdifferfromthecounterpartatthevarious proteincontentsofthediet.Onthecontrary,differencesbetweenthebreedsemergedinthenitrogenutilizationforwhich CintaSenesewaspenalizedmoreandmoreasdietaryproteincontentincreased.TheseresultssuggesttolimittheDCP contentforthelocalbreed,alsowiththeaimtoreducenitrogenpollutionintheenvironment.
Acknowledgements
Thisstudywassupportedbygrantof ARSIA(Tuscany Region).TheauthorsthankMr.SilvanoLancinifor technical assistanceand“EnteCassadiRisparmiodiFirenze”forfinancialsupportforSASlicence.
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