16.4rrrr333

EFFECTSOFSTAGEOFMATURITYOFTIMOTHYHAYANDCONCENTRATESUPPLEMENTATIONONPERFORMANCEOFLACTATINGDAIRYCOWSC.
VINET1,R.
BOUCHARD2,andG.
J.
ST-LAURENT3rO.
A.
R.
D.
C.
DairyScienceDepartment,Wooster,Ohio44691,zAgricultureCanada,Lennoxville,QuebecJIM123,andsUniversitiLaval,DdpartementdeZootechnie,QudbecGIK7P4.
Received2lMar.
1979,accepted26Feb.
1980.
VIuer,C.
,BoucunnD,R.
,ANDSr-L,qunENr,G.
J.
1980.
Effectsofstageofmaturityoftimothyhayandconcentratesupplementationonperformanceoflactatingdairycows.
Can.
J.
Anim.
Sci.
60:5ll-521.
Theeffectsofconcentratesupplementationoftimothyhaycutatthelate-bootandearly-bloomwastestedwithdairycowsduringtwofeedingandtwodigestibilitytrials.
Thedietsforeachtrialcontainedthefollowinghaytoconcentrateratios:100:0,85:15,70:30and55:45.
Dailydrymatterintakeandfat-correctedmilkproduction,respectively,were15.
1,16.
8,18.
6,19.
4kg;16.
7,20.
7,23.
1,21.
0kgforthefourdietscontainingearly-cuttimothyhayand11.
0,14.
7,l'1.
2,19.
8kg;8.
4,10.
7,13.
3and15.
9kgforthelate-cuttimothyhay.
Percentdigestibilitiesofthefourdietscontainingearly-cutandlate-cuttimothyhay,respectively,were65.
6,65.
6,66.
9,66.
8and53.
6,53.
6,60.
2,62.
9fordrymatter;62.
5,63.
7,65.
2,65.
3and24.
0,39.
3,53.
3,60.
0fornitrogen;'10.
3,'70.
3,68.
4,67.
8and53.
7,53.
4,60.
1,62.
6forgrossenergy;66.
4,65.
3,67.
1,66.
6and55.
0,54.
5,61.
4,63.
5forcellwallconstituents;68.
2,65.
8,9.
9,63.
4and50.
8,48.
2,52.
7,52.
1foraciddetergentfiber.
Timothyhaycutatlate-bootstageassolesourceoffeedsupportedadailymilkproductionof16.
7kgcomparedto15.
9kgforcowsconsumingtimothyhaycutatlate-bloomstagesupplementedwith9kgofconcentrate.
Ona6valu6I'effetdelacompl6mentationauxconcentr6sd'unerationdefoindefl6olecoup6eauxstadesdelafindel'6paisonetdud6butdelafloraisonsurlaperformancedevacheslaitibresaucoursdedeuxessaisd'alimentationetdedigestibilit6respectivement.
Lesrationsutilis6esdanschaqueessaicontenaientlesrapportssuivantsdefoinetdeconcentr6s:100/0,85/15,70/30et55145.
L'ingestionquotidiennedematidresdcheetlaproductionlaitibrecorrig6epourlamatidregrasseont6t6del5.
1,l6.
8,18.
6,l9.
4etde16.
7,20.
7,23.
1,21.
0kgrespectivementpourlesquatrerationscontenantdufoindefl6olefauch6et6tetde11.
O,14.
7,17.
2,19.
8et8.
4,10.
7,13.
3,15.
9kgrespectivementpourlefoindefl6olefauch6etard.
Lestauxdedigestibilit6desquatrerationscontenantdufoinprovenantdesdeuxstadesdecroissancerespectivementont6t6de65.
6,65.
6,66.
9,66.
8et53.
6,53.
6,60.
2,62.
9pourlamatibresbche,de62.
5,63.
7,65.
2,65.
3et24.
0,39.
3,53.
3,60.
0pourI'azote,de70.
3,'70.
3,68.
4,67.
8et53.
7,53.
4,60.
l,62.
6pourlavaleur6nergtitiquebrute.
de66.
4,65.
3,67.
1,66.
6et55.
0,54.
5,61.
4,63.
5pourlesconstituentsdesparoisceIIulairesetde68.
2,65.
8,64.
9,63.
4et50.
8,48.
2,52.
7,52.
1pour1'analysedelacellulosepard6tergentacide.
Lefoindefl6olecoup6eaustadedelafindel'6piaisonetutilis6commeseulesourcedenourritureapermisuneproductionlaitibrequotidiennede16.
7kg,contre15.
9kgpourlesvachesconsommantdufoindefl6olecoup6eaumdmestadeetadditionn6de9kgdeconcentr6s.
Timothy(PhleumpratenseL.
)iswidelydairycows,andsincetheresearchofusedinEasternCanadaashavforfeedinsColovos(1949)iittlehasbeendoneonthedigestibilityoftimothyhayinthecontextofCan.
J.
Anim.
Sci.
60:511-5zl(JuneleE0)milkproduction'Thefeedingvalueofhayis5ll512CANADIANJOURNALOFANIMALSCIENCEaffectedbythestageofmaturityatharvest.
D6marquilly(1968)demonstratedthatthestageofmaturitywasthemostimportantfactoraffectingthedigestibilityofgrasshay.
Levelofdigestibilitywasmaximumatthebeginningofthevegetativecycleanddecreasedinalinearfashionuntilthebloomstage.
Thecapacityofruminantstodigestandutilizefibrousmaterialsuggeststhatforageshouldbemaximizedindairycattlediets.
However,foragesupplementationwithaconcentratefeedisrequiredinordertoobtainhighlevelsofmilkproduction.
Voluntaryintakeisincreasedwiththeadditionofconcentratetodairycattlediets(Coppocketal.
1974;Moseleyetal.
1916)buthighlevelsofconcentrateinthedietoftendecreaseallnutrientdigestibilities(Belletal.
1963;LassiterandBrown1962;LovellandRusoff1963).
Dietsupplementa-tionwithconcentratefordairycowsisafunctionofthenutrientconcentrationintheforage,whichinturnisafunctionofthestageofmaturityoftheforage(CramptonandForshaw1939;CramptonandJackson1944).
Thepresentitudywasundertakentocomparethefeedingvalueforlactatingdairycowsoftimothyhayharvestedattwostagesofmaturityandsupplementedwithvaryingproportionsofconcentrate.
Theeffectsofthesetwoparametersondrymatterintake,ornutrientutilization,andonmilkproductionanditscomposition,wereinvestigated.
MATERIALSANDMETHODSExperimentl.
Late-CutTimothyHayasForageTnre.
l1.
DrcesTIerLrTyrRrAL.
Sixteenlactat-ingHolsteincowsintheirfifthmonthoflactationwererandomlyassignedtooneoffourhayandconcentraterations,usingacompletelyran-domizedblockdesign.
A9-dayperiodforrationadaptationprecededthetwo5-dayperiodsoftotalfecesandurinecollection.
Therationscontainedthefollowinstimothyhaytoconcenrrateratios.
onadrymatteibasis:100:0,toserveasthecontrol;85:15,70:30,55:45(Table1).
ThetimothyhaywasharvestedinJuly,atthelate-bloomstage.
Theconcentratef'eedcontainedthefollowingingredients:rolledwheat,8.
87o;rolledbarley,29.
97c;rolledoats,l0olo;rolledcorn,l5.
l%;distillers'grains,ll.
2c/c;soybeanmeal,16.
4o/o;molasses,5%;dicalciumphosphate,l.
5tlo;calciumcarbonate,lTc;salt,lVc;vitamin-mineralsupplement,O.
12Vocontainingperkilogram11259920lUofvitaminA,2126'/81IUofvitaminD.
,,3.
67cMn,0.
57oCu,0.
4137oCo,O.
4VcFe,O.
156Va1,2.
97:Zn,14.
7Caand16.
6VoP.
Thecowswerehousedinatie-stanchionbarnequippedwithautomaticwateringbowlsandindividualfeedingboxes.
Haywaschopped(5-8cm)andfedadlibitum.
Theamountofconcentratefedwasbasedonthepreviousday'shayconsumptionforeachofthethreeexperimen-taldietscontainingconcentrate.
Residualfeedamountedtoapproximarely1O-157aandwasrecordeddaily.
Thecowsweremilkedtwicedailyandproductionwasrecorded.
Fourcompositesamplesofconsecutivenightandmorningmilkingsweretestedforeachcowonceweeklyforpercentagesofdrymatter,milkfat,solids-not-fatandprotein.
Totalcollectionsoffecesandurineweremadeduringthelast5daysofthetwo14-dayperiods.
Aurinarytubewasattachedtothecowandurinewascollectedinastainlesssteelcontainer.
Samplesoffeces,urineandmilkweretakendailyandcompositedpercowforthetwo5-dayperiodsforlaboratoryanalysisanddrymatterdetermina-tion.
Dailysamplesoffeedandresidualfeedwerecompositedforanalysis.
Bodyweightswererecordedweeklyonthesamedayandatthesamehour.
Tnrel2.
FeeorNcrnr,4.
r-.
SixteenlactatingHolsteincowsintheirfifthmonthoflactationwereassignedduringaperiodof4wktoacompletelyrandomizedblockdesignasintrial1.
Treatmentsconsistedofthesamefourexperimen-taldiets(TableI).
Thecowsweremanagedinthesamemannerasthoseintrial1,neglectingcollectionofexcrements.
Feedintakeandmilkdata,aswellassamplesoffeeds,refusedfeedandmilk,wereobtainedandcollectedfollowingthesameprocedureandtimingasintrial1.
Experiment2.
Early-CutTimothyHayasForageTnrnl3.
DrcpsrrsrLrrvrnr.
r.
l.
EightlactatingHolsteincowsattheirthirdmonthoflactation!
E!
oEOFnr.
;:r;@+.
{UoJa$\od6o-r+oic;a;qn-nd*6r$r4_oqI!
.
-JZEETE=5s--Eil::92B!
.
=Fil=E>hP;go.
E-"PgX=96ac:-EE;;.
E&E:>E=EF,EEEQQQXts>A&3&cia.
do!
go.
oo-';aOE:3.
-=.
2a^6>,;zoEXEoEEgE'oE;d9Ecoo3'-5EEE>-ztr;o-y\++@sEE!
Eo,oFog,oF(AYrIII_l5l{l*ilril:l=lIIfiAOOsrNON-_:.
'ldOC;6@-.
Or;oq-dno+o\oo'.
.
66!
e=F-0QEs-Sgege,gisYtrtrtrq-+-a:-.
=8;;F*iE*stEA6t>trtr>adOOVINETETAL.
-DAIRYCOWPERFORMANCE515.
-5h.
E'aEEg6o,;.
i;g39O2aE9.
i.
-E!
i>-xAztr,9=,9-!
sts:9E-YEEEE=F936b**5_:E=i$Er++@sMitkProductionandComPositionMilkproductionincreasedsignificantly(P0.
05)betweencowsfed3Oand45Votimothy.
Intrial4withearly-cuttimothy(Table3)fat-correctedmilk(FCM)produc-tionwassignificantlyreducedforcowsreceiving457oconcentratesuchthatitwasnotsignificantlydifferentbetweencowsfed15and45Eoconcenltate.
ConcentratesupplementationincreasedFCMproductionmarkedlyforcowsreceiv-inglate-cuttimothy(Table2),butevenwith457oconcentrateintheration,FCMproductionwasnotashighasthatofcowsfedearly-cuttimothyandnoconcentrate(Table3).
Itisimportanttoconsiderthatthecowsconsumingthelate-cuttimothyhadapproximately2mooflactationmorethanthecowsconsumingtheearly-cuttimothyhay.
Thismayexplainalowermilkproductionforthecowsonthelate-cuttimothyhaytreatments.
TheincreaseinFCMproductionfollowedtheincreaseincrudeproteinofthediets,whichvariedfrom5.
4toI7.
6VointrialsIand2ofexperimentIandfromI1.
3tol4.
4%ointrials3and4ofexperiment2(Tablel).
AsimilartrendwasobservedininvestigationsbyGordon(1917),Grieveetal.
(1974)andNelsonetal.
(1968).
Nelson's(1968)datashowedthatmilkandFCMproductionincreasedfrom12.
3to19.
7kgandfromI1.
6to14.
5kg,respectively,withdietscontainingcoastalBermudagrassvaryingincrudeproteincontentfrom8.
7tol5.
6qo.
AccordingtoBrattonetal.
1943,proteinqualitydoesnotaffectmilkproduction;possiblythediffer-encesseenbetweenthepresentmilkproductiondataandthoseofNelsonetal.
(1968)atsimilarcrudeproteinlevelsareprobablyduetothehigherdrymatterintakeofrationscontainingearly-cuttimothy,whichwasperhapsmorepalatablethanthecoastalBermudagrass.
Drymatterintakewas3.
63VoofBWforthedietofearly-cut516CANADIANJOURNALOFANMALSCIENCEtimothycontaining14.
4Vocrudeproteinascomparedwtth3.
2VoofBWfordietsofcoastalBermudagrasscontaining13.
1and15.
6crudeprotein.
Concentratesupplementationdidnotsignificantlyaffectmilkfatpercentageinalltrials,exceptforasignificantdecreaseintrial4withthedietconraining45Voconcentrate.
Thepercentageofsolids-not-fat(SNF)isincreasedsignificantlywithconcentratesupplementationintrialsIand2withlate-cuttimothy.
Inthecaseofearly-cuttimothy,SNFwassignificantlyincreasedonlyintrialwiththedietcontaining457oconcentrate.
Thismaybeduetothedecreaseinmilkfatpercentage.
TheincreaseinSNFseenintrialsIand2,andthevariationofSNFseenintrials3and4followthetrendofdigestibleenergyintake.
ThiscoincideswithresultsofNelsonetal.
(1968).
Concentratesupplementationaswellashayqualitycausedanincreaseinmilkproteincontent,reflectingtheincreasingcrudeproteincontentofthediets.
Thereisnofurtherincreaseoncethe30%concentratelevelisreachedwiththerationcontainineearly-cuttimothy.
whichhasacrudeproteiicontentofl3.
4Vo.
AsimilartrendwasobservedininvestigationsbyNelsonetal.
(1968),inwhichtherewasanincreaseinmilkproteinfrom2.
86to3.
42Vowithdietsof8.
7to18.
8%crudeprotein;however,thedifferenceswerenotsignificantbetweenrationsof13.
1,15.
6and18.
87ocrudeprotein.
Emery(1978)notedthatmilkproteinpercentagevariedfrom2.
6to3.
6V0withdietsof9-1l%ocrudeprotein.
NutrientDigestibilityTherewasanincreaseinapparentdrymatter,grossenergyandcellwallcon-stituentsdigestioncoefficientsasmoreconcentratewasaddedtorationscontaininslate-cuttimothyintrialI(Table41.
However,differenceswerenotsignificant(P>0.
05)betweenrationscontainingthetwolowestandbetweenrationscontaininsthetwohighestconcentratelevels.
Rpparentnitrogendigestibilitywasincreasedmar-!
o-pEo,aFaEoiEJsor,;OY6@Ednano-ONO-Noqocn9nqrn\oo@\o\o\ohnr$O\oor-@hnoonnN\or\o\o\o+on*N6oON\O@$r\o\o+aOn-Ocicior;ai+@hNd-oSrrOOoF:-\on\onN.
sa-osrJljg=ql!
c.
!
.
joo6+@-nno6+--Q-QaACB\OTOOh\od+r;daiOhNhn-t'6qG-8Ebft-=i:oE.
:-6"6]'5^o"P*"EE":giEEY&SE.
0,rY-Etrafi.
:6'-*aazQFBVINETETAL,-DAIRYCOWPERFORMANCE5l'7kedlyfrom247aonalltimothyto607owhentherationcontained45Voconcentrate.
Incontrast,concentratesupplementationtodietscontainingearly-cuttimothy(trial3)causednosignificant(P>0.
05)changeinapparentdrymatter.
grossenergy.
nitrogenandcellwallconstituentsdigestioncoeffi-cients"Theaveragesare,respectively,66.
2,69.
2,64.
2and66.
47o.
Thelowlevelofcrudeproteinandhighlevelsofaciddetergentfiberandlignin(Tablel)inlate-cuttimothyexplainthelowdigestibilityoIdrymatterenergy.
nitrogenandcellwallconstituents(Table4).
Theproteindeficiencyisalleviatedwithconcen-tratesupplementationabovel57ainthediet;fiberdigestionisstimulatedandthusdigestiveutilizationofthenutrientsisincreased.
Thiseffectisnotseenintrial3withtheearly-cuttimothy,becauseofthehighlevelofcrudeproteinandlowlevelofaciddetergentfiberandlignin(Table1).
Colovosetal.
(1949)noteddifferencesinpercentdigestibilityofproteinandgrossenergyof25.
2Voandl5%o,respectively,fortimothyhaysharvestedlateandearlywithcrudeproteincontentsof4.
5and7.
9Vo,respectively.
Theseresultsarecomparablewiththedifferencesinproteinandgrossenergydigestibilityof36and16.
6Vo,respectively,forlate-andearly-cuttimothyhaysofthepresentstudywithcrudeproteincontentsof5.
4and11.
3Vo,respectively.
TherewerenosignificantdifferencesinaciddetergentfiberdigestibilityintrialI(Table4).
Intrial3,digestibilityvaluesofaciddetergentfiberarehigherwithearly-cuttimothythanthevaluesobservedwithlate-cuttimothybutwithoutsignificantdifferencesbetweenthethreerationscontainingconcentrate.
Thesedietsaverageanaciddegergentfiberdigestibilityof64.
l%o,whichislowerthanthevalueof68.
27ooftheall-hayrationintrial3(Table4).
Thehighercontentoflignininthelate-cuthaycouldexplainthedifferenceindigestibilityofthefiber.
Tomlinetal.
(1965)andVanSoest(1973)haveshownahighnegativecorrelationbetweenlignincontentandcellulosedigestibility.
Thedecreaseddigestibilityoftheaciddetergentfiberwithconcentratesupplementationinrationscontainingearly-cuttimothyisprobablyduetothechangesinrumenfermentationcausedbytheconcentrate.
Digestibilityofthenitrogenintheaciddetergentfiberwasincreasedwithincreas-ingconcentratesinrationscontainingbothhays,butthedifferencesintrialIarenotsignificant(Table4).
AlthoughthisnitrogenisaproductoftheMaillardreactionwherebyaninsolubleandindigestiblecomplexisformed(VanSoest1969),thepresentdataimplythatitisdigestibletoacertainextent.
Itsdigestibilitypeaksat587owiththerationcontainingearly-cuttimothyand457oconcentrate.
Perhapsthenitrogenfractionintheaciddetergentfiberoftheconcentrateismoredigestiblethanthesamefractioninforages.
EnergyDataInTrial1concentratesupplementationincreasedgrossenergyintakesignificantlyuptothelevelof307oconcentrate(Table5).
Thereisfurtherincreasewiththedietcontaining45Voconcentrate,butthediffer-enceisnotsignificant.
GrossenergyintakeofcowsintrialIreceiving307oconcentrateequalsthatofcowsintrial3receivingonlyearly-cuttimothy.
Intrial3,concentratesupplementationincreasedintakesignific-antlyuptothelevelof30Voconcentrate,afterwhichthereisnofurtherincrease.
Comparingthetwoall-haydiets,thereisadifferenceof126.
4MJbetweengrossenergyintakesinfavoroftheearly-cuttimothy.
Poorenergyandfiberdigestibilityofthelate-cuthaylimiteditsgrossenergyintake.
BlaxterandWilson(1963)andLeaver(1973)obtainedsimilarresultswithhaysofdifferentqualities.
Lossesofgrossenergyinfecesandurinewerefairlysimilarinbothtrials(Table5).
Grossenergyproducedinmilkwasincreasedsignificantlywithincreasingcon-centrateindietscontaininglate-cuttimothyandwasfurtherincreasedindietscontaining518!
oFo.
oF6E-;o=oJo9or.
;@or.
;ongnqnoqoloNc)odoNNrr$-ooN-ro+dioNno,+V$.
_OaN-\o6NAAB-QS-+d\ON660noO_OO--Nd+@o-NOO6+orn-OHNg6aarrdrN$9d-rNs!
s-Qo,6*ol\orroiN-tsaanqqCcn6hrrrdN+Ni-N@N6h6$Oh-6Nnqcl\n+O-haE6v!
>EEEA_>s.
E.
!
=HIEETIiA'i5CANADIANJOURNALOFANIMALSCIENCEO5=d-E.
so,ogE;!
'i;.
;>doavPs98.
:Eq-3b>Filearly-cuttimothy.
Thedifferencebetweendietscontainingthetwohighestconcentratelevelsandearly-cuthaywere,however,notsignificant.
Digestibleenergyintake(DEI)increasedwithincreasingconcentratewithrationscontaininglate-cuttimothy,butDEIisstablewithrationssupplementedwithconcentrateandcontainingearly-cuttimothy(Table5).
Thustheefficiencyofutilizationofenergyfromexcellentqualitytimothyseemstoequalthatoftheconcentrate.
Gordon(1977)observedsimilarresultswithdriedgrassasaforageofexcellentqualityandofhighenergyvaluewhichcouldsubstituteforamajorpartoftheconcentratewithoutaffectingmilkproductionorcomposition.
SimilarobservationsweremadebyMontgomeryetal.
(1976),whostatethatcowscompensateforthereductioninenergyintakefromconcentratebyconsumingmoreforageofexcellentquality,suchthatmilkproductionisnotlimitedbyenergyintake.
Effectively,maximummilkproductioninthepresentstudyispracticallyattainedwiththerationcontainingl57oconcentrateandearly-cuttimothy.
Digestibleenergyintakeisincreasedsignificantlyfrom115.
9to242.
7MJwithincreasingconcentrateinrationscontaininglate-cuttimothy(Table5).
Digestibleenergyintakeintrial1isstronglycorrelated(P{0.
05)withdrymatterdigestibility(DMD)andthefollowingregressionequationdescribestherelationship:DEI(MIIDAY):.
694DMD-r24.
tR:0.
82.
However,intrial3withearly-cuttimothy,digestibleenergyintakeisin-creasedonlyslightlyuptothelevelofl5voconcentrate,afterwhichthereisnosignificantdifference.
Thecorrelationwithdrymatterdigestibilityisnotsignificant(P>0.
05)(R:0.
295).
TheseresultsagreewiththoseofBlaxteretal.
(1961),Camplingetal.
(1961).
Conradetal.
(1964)andMcCullough(1969),whodemonstratedthatthepositiverelationshipbetweendigestibleenergyintakeanddrymatterdigestibilityistrueonlyupuntilacertainlevelofVINETETAL.
-DAIRYCOWPERFORMANCEdigestibility(approximately68Vo)afterwhichdrymatterintakeisnegativelyrelatedtodigestibilityandDEIisconstant.
Drymatterdigestibilityoftheearly-cuttimothyintrial3isapproximately67Voandthusrumenloadandrateofpassagewerenotlimitingfactorsonenergyintakeastheywerefordietscontainingthelate-cuttimothyintriall.
Whenthesephysicalfactorsdonotlimitintakeastrial3,cowsdecreasetheirdrymatterintaketomaintainDEIagcordingtoproductionneeds(Andrewsetal.
1969:CowsertandMontgomery1969).
NitrogenBalanceNitrogenintake(Table6)increasedlinearlyinbothtrialsIand3,reflectingtheincreasedpercentageofcrudeproteininthediets(Tablel)withincreasedconcentrateandhayquality,aswellasincreasingdrymatterintake.
Fordatafrombothtrials,nitrogenintake(NI)ishighlycorrelated(PNF=6E5.
EHP=E",q,i,lFiE:E=Zrr.
)519A5,9)*EXOc=Lo-ZP->NiE;-)o62a3il.
9Ea!
.
si9=i:N-r:tEe2OE:9O::;,9>fiEl520CANADIANJOURNALOFANIMALSCIENCEbecameoflesserimportancewiththerationity,mitkproduction,andefficiencyofproduc-containing55Voearly-cuttimothy:45Votion.
J.
DairySci.
46:623.
concentrate.
NitrogenretentionwasnegativeintrialIfordietscontaining100and857olate-cuttimothy.
Thesedietswereprotein-deficient.
Nitrogenintakeanddigestibilitywerelow(Table6).
Nitrogenretentionandutilizationwerebothincreasedsignificantlywithconcentratesupplementation.
Maximumvaluesfornitrogenretentionwereobservedwiththedietcontaintng7}Voearly-cuttimothy:307oconcentrate;additionalcon-centratelowerednitrogenretentionandutilization,althoughthisdifferencewasnotsignificant(P>0.
05).
Thisisduerothehighlevelofnitrogenexcretedintheurineobservedwithasupplementationof45Tcconcenffate.
Thepercentageofefficiencyofnitrogenutilizationwasonly5.
37cwhenlate-cuttimothywastheonlyfeedintrial1,andwasrncreasedwithconcentratesupplementation.
However,thethreedietscontaininsconcen-tratedidnotdiffersignificantly.
Inconclusion,drymatterintakeoftimothyhaycutatlate-bootstagerep-resented2.
147oofbodyweightwithadrymatter,nitrogenandgrossenergydigestibit-ityof65.
6,62.
5and10.
3Vo,respectively.
Dailymilkproductionsupportedbyearlycuttimothyhayassolefeedwasl7kg.
Inordertoobtainthecomparableperformance,late-cuttimothyhayhadtobesupplementedwith9kgofconcentrate.
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Prod.
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andWILSON,R.
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