Voluntary intake, apparent digestibility and nitrogen balance by sheep supplemented with Leucaena leucocephala

摘要

nbsp;ThisstudyaimedtoevaluatesupplementationofLeucaenaleucocephala(leucaena)forruminantandtheeffectsofcondensedtannininrumenfermentation.EightSantaInêsbreedsheep(bodyweight=35±2.6kg),wereallocatedtofourdietsmixedinarandomizedblockdesign.Animalswerekeptinindividualpensforaseven-dayfeedadaptationfollowedbyaseven-dayintaketrialwherevoluntarydrymatterintake(VDMI)wasestimated.Thesheepwerethenmovedintometaboliccagesforafive-daydigestibilitytrialtoestimateapparentdigestibilityandnitrogenbalance.Thetotalexperimentlasted70daysdividedintotreeperiods(blocks)of21days,leavingtwodaysbetweenperiodsforanimalrest.ExperimentaldietswerebasedonTifton85hybridBermudagrass(CynodondactylonPers.nbsp;×nbsp;CynodonnlemfuensisVanderyst)andsupplementedwith20(L20),40(L40)and60%(L60)ofleucaenahayrelatedtodietdrymatter.Controldietwascomposedbytiftonhayandsupplementedwithmixproteinconcentrate.Chemicalcompositionandcondensedtanninsdeterminationwereperformedonofferedandrefusedfeedandexcretionsamples.Dataweresubjecttoanalysisofvarianceusinggeneralprocedureofthestatisticalsoftwarepackage.MeanswerecomparedbyStudent`ttest(0.05)andlinearandquadraticregressionswereappliedtoevaluatetheeffectofleucaenalevel.nbsp;SupplementationwithL40increased29%VDMI(g/animal.day),whilesheepfedL20presentednodifference(Pnbsp;nbsp;0.05)tocontrolandL60diet.Theaverageresponsesofapparentdigestibilityamongleucaenadietswere384(SE=10),341(SE=24),288(SE=53)and365(SE=24)g/KgfortotalDM,CP,ADFandNDF,respectively,whichwerelower(P0.05)thancontroldiet(504,630,557,459,respectively).Itissupposedthatthelowdigestibilityfoundwithsupplementationwasduetocondensedtannineffect,highindigestiblefibrecontendandtheadditiveactionofboth.SupplementationwithL60andL40increasedfaecalnitrogenexcretion(FN)andfaecalaciddetergentsolublenitrogen(Pnbsp;nbsp;0.05).However,animalsfedL20reduced64%urinarynitrogen(UN)lossrelatedtocontroldietandpresentedsimilarFNthancontrol(Pnbsp;nbsp;0.05).L60andcontroldietpresentedthehighestNretention(Pnbsp;nbsp;0.05).Ingeneral,thehighlevelofleucaenasupplementation(40and60%)shouldbeexploitedwithhigherdigestiblenutrients,inordertosynchronizethe#8220;excess#8221;proteininrumenandenergy.nbsp;Itisconcludedthatphenoliccompounds,especiallycondensedtannin,presentinleguminousmayinfluencepositivelydigestiveparameter;howeveritseffectdependsonotherfactorsuchaspresenceoflignin,availableenergyandalsoitschemicalcharacteristic.