Grazing systems and management strategies for lactating Holstein cows in Florida

229 Pages·1999·8.5 MB·English

by  Fike, John Herschel

GRAZINGSYSTEMSANDMANAGEMENTSTRATEGIESFORLACTATING
HOLSTEINCOWSINFLORIDA
By
JOHNHERSCHELFIKE
ADISSERTATIONPRESENTEDTOTHEGRADUATESCHOOL
OFTHEUNIVERSITYOFFLORIDAINPARTIALFULFILLMENT
OFTHEREQUIREMENTSFORTHEDEGREEOF
DOCTOROFPHILOSOPHY
UNIVERSITYOFFLORIDA
1999
ACKNOWLEDGMENTS
Thisworkcouldnothavebeencompletedwithouttheassistanceofseveral
people. Thanksfirstgotomywife,Wonae,withoutwhosepatience,assistanceand
understandingthisworkcouldnothavebeencompleted. Thesupportandencouragement
oftheauthor'sparentsandfamilyalsowereinstrumentalinmakingthisdissertation
possible.
Theauthorwishestoexpresshisgratitudefortheteaching,directionandpatience
receivedfromhisadvisorsDr.CharlesR.StaplesandDr.LynnE.Sollenberger. The
ChurchillianwordsofencouragementfromDr.Staplesthatcameduringsomedarkhours
willnotbeforgotten.
ThanksalsogotoDr.JohnE.Mooreforencouragement,mentoring,andexcellent
teaching. Drs.MaryBethHallandPeterJ.Hansenalsowereinstrumentaltothiswork
byprovidingexcellentteachingandassistancewhetherinoroutoftheclassroom.
Tomyplastic-sleevedcompatriots,BisoondatMaccoonandRenatoFontanelli,
thewishisextendedthatthoughyouhaveadequatesample,yourfecal-samplecupswill
neverrunnethover.
OtherstoberecognizedfortheirhelpincludeD.Hissem,J.Lindsay,andM.
Russellforfarmsupport,Drs.R.E.LittellandC.R.Wilcoxforstatisticalassistance,and
Dr.H.H.Headforassistancewithimmunoassays. ThankstoO.A.Carrijo,Jr.,J.Hayen,
E.M.Hirchert,andJ.P.Jenningsforassistanceinthelaboratory,atthefarm,orboth.
ii
ThanksforthegenerousfinancialassistancegivenbytheDeanforAcademic
ProgramsforthefirstyearandtheDepartmentofDairyandPoultrySciencesforthe
remainingyears. ThanksalsogotoAmericanFarmBureau,CBAG,andMonsantofor
theirfinancialassistanceoftheresearch.
iii
TABLEOFCONTENTS
page
ACKNOWLEDGMENTS
ii
LISTOFTABLES vii
LISTOFFIGURES ix
KEYTOABBREVIATIONS xi
ABSTRACT xii
CHAPTER1.INTRODUCTION 1
CHAPTER2. LITERATUREREVIEW 3
ClimaticChallengestoSoutheasternDairies 4
ClimaticAnimals 6
EnergyConsiderationsfortheGrazingRuminant 7
SomeAnimalandNutritionalFactorsInfluencingFeedIntake 9
SomeNon-NutritionalFactorsAffectingBehaviorandForageIntakeofGrazing
Ruminants 13
MechanisticComponentsofForageIntake 13
DaylightandTemperature 17
MeasurementofForageIntakeinGrazingRuminants 18
HerbageAllowanceandStockingRateEffectsonForageIntakeandPerformance
ofRuminants 21
SupplementEffectsonAnimalPerformancewithParticularEmphasison
LactatingCowsinPasture-BasedDairySystems 25
SupplementEffectsonProduction 26
SupplementEffectsonIntake 29
SupplementEffectsonForageDigestibility 33
SynchronizingNitrogenandCarbohydrateSupplementstoIncreaseMicrobial
ProteinSynthesisintheRumen 37
LossofFeedNitrogeninRuminants 37
ResponsestoSupplementalCarbohydrate 39
EffectsofSupplementFeedingFrequency 42
EffectsofTimingofSupplementProvisionRelativetoForageIntake 44
AdditionalEnergyandProteinSupplementsforAnimalsonPasture 45
Fats 45
EscapeProteins 46
iv
EffectofSupplementsonGrazingBehavior 47
InteractionsofSupplementandHerbageAllowanceonPerformanceofLactating
CowsinPasture-BasedDairySystems 49
TwoPerennialForagesforLactatingCowsinPasture-BasedDairySystemsinthe
Southeast 51
Bermudagrass 51
ComparisonsofGrassesandLegumes 60
RhizomaPeanut 63
SomeManagementStrategiesfortheImprovementofMilkProductionin
SubtropicalEnvironmentsSystems 67
BovineSomatotropin(bST) 67
EffectsofHeatonMilkProductionandCoolingStrategiesforPasturedCows 70
bSTinHotEnvironments 72
CHAPTER3.PASTURE-BASEDDAIRYPRODUCTIONSYSTEMS:
INFLUENCEOFFORAGE,STOCKINGRATE,AND
SUPPLEMENTATIONRATEONANIMALPERFORMANCE 75
Introduction 75
MaterialsandMethods 77
Cows,Design,andTreatments 77
ExperimentalProcedures 81
StatisiticalAnalyses 86
ResultsandDiscussion 87
ForageComposition 87
MilkProductionandCompositionperCow 89
MilkProductionperLandArea 100
BodyWeightandCondition 101
Respiration,Temperature,andBloodMetabolites 105
IntakeofOrganicMatterandNutrients 109
TreatmentEffectsonForageNutritiveValueEstimates 117
TreatmentEffectsonHerbageMass,Availability,andIntakeEstimatesas
DeterminedbyPastureSampling 120
SimpleEconomicAssessmentofSupplementation 125
Conclusions 127
CHAPTER4.PASTURE-BASEDDAIRYPRODUCTIONSYSTEMS:
INFLUENCEOFHOUSING,bST,ANDFEEDINGSTRATEGYON
ANIMALPERFORMANCE 130
Introduction 130
MaterialsandMethods 131
Cows,Design,andTreatments 131
ExperimentalMeasurements 134
StatisticalAnalysis 142
ResultsandDiscussion 145
GrazingTimeandIntakeofOrganicMatter 145
MilkProductionandComposition 150
v
BodyWeightandComposition 155
PlasmaIGF-1andInsulin 157
RespirationRatesandBodyTemperatures 159
Conclusions 163
CHAPTER5.FINALSUMMARYANDCONCLUSIONS 167
APPENDIX1.SASPROGRAMOFPONDETAL.(1987)FORTHE
ESTIMATIONOFFECALOUTPUT 181
APPENDIX2.SASPROGRAMTOADJUSTFORAGEINTAKEUNTIL
FECALOUTPUTOBSERVEDANDFECALOUTPUTPREDICTED
DIFFERBYLESSTHANONE-HUNDREDTHOFAKILOGRAMPER
DAY 182
APPENDIX3.RAINFALLANDTEMPERATUREDATAFORGRAZING
TRIALSIN1995,1996,AND1997 183
LISTOFREFERENCES 184
BIOGRAPHICALSKETCH 214
vi
LISTOFTABLES
Table page
3.1 IngredientandchemicalcompositionofsupplementsfedtolactatingHolsteincows
onpasture 79
3.2 Nutritivevaluecharacteristics,chemicalcomposition,andcalculatednetenergyof
lactation(NEl)andtotaldigestiblenutrients(TDN)ofTifton85bermudagrassand
Florigrazerhizomapeanutpastures. Sampleswerehand-pluckedonceeachperiod,
basedonvisualappraisalofforageconsumedbygrazingcows.
88
3.3 Effectofforage,stockingrate(SR),andsupplementationrate(SUP)onmilk
productionandcompositionofHolsteincowsgrazingTifton85bermudagrassand
Florigrazerhizomapeanutduringthesummersof1995and1996 90
3.4 Effectofforagespecies,stockingrate(SR),andsupplementationrate(SUP)on
bodyweight(BW)andbodyconditionscorechange(ABCS),respirationrate(RR),
bodytemperature(TEMP),andplasmaureanitrogen(PUN)andplasmaglucoseof
HolsteincowsgrazingTifton85bermudagrassandFlorigrazerhizomapeanut
duringthesummersof1995and1996 102
3.5 Effectofforagespecies,stockingrate(SR),andsupplementationrate(SUP)on
forage,supplementandtotalorganicmatterintake(OMI),andonforage,
supplement,andtotalorganicmatterintakeasapercentofbodyweight(OMIPBW)
ofHolsteincowsgrazingTifton85bermudagrassandFlorigrazerhizomapeanut
duringthesummersof1995and1996 110
3.6 CalculateddailyintakeofnutrientsbycowsgrazingTifton85bermudagrass(BG)
orFlorigrazerhizomapeanut(RP)pastures. Cowsreceivedsupplement(SUP)at
either0.33kg(Low)or0.5kg(High)(as-fed)perkgofdailymilkproduction 114
3.7 Effectofforage,stockingrate(SR),andsupplementationrate(SUP)onbodyweight
(BW)change,4%fatcorrectedmilk(FCM)production,andmeasuresofenergy(E)
statusofHolsteincowsgrazingTifton85bermudagrassandFlorigrazerhizoma
peanutduringthesummersof1995and1996 115
3.8 Effectofforagespecies,stockingrate(SR),andsupplementationrate(SUP)on
forage,supplementandcrudeprotein(CP),invitroorganicmatterdigestibility
(IVOMD),andneutraldetergentfiber(NDF)concentrationsinTifton85
vii
bermudagrassandFlorigrazerhizomapeanutduringthesummersof1995and1996.
Sampleswerehand-pluckedonceeachperiodbasedonvisualappraisalofforage
consumedbygrazingcows 118
3.9 Regressiongroupingsandregressioncoefficientsforpredicting1995and1996pre-
andpost-grazeherbagemassofTifton85bermudagrassandFlorigrazerhizoma
peanutpastures 121
3.10Diskmeterestimatesoftheeffectofforagespecies,stockingrate(SR),and
supplementationrate(SUP)onforagepre-andpost-grazeherbagemass(HM),
herbageallowance(HA),anddrymatterintake(DMI)ofgrazing,lactatingHolstein
cowsgrazingTifton85bermudagrassandFlorigrazerhizomapeanutduringthe
summersof1995and1996 122
3.11Effectofforagespecies,stockingrate(SR),andsupplementationrate(SUP)onmilk
incomeminussupplementcosts(MIMSC),assumingsupplementintake
proportionatetoLSmeansofmilkproductionwithinagivenSUPtreatmentand
calculatedonbothpercowandperlandareabases 126
4.1 Supplementingredients 133
4.2 Chemicalcomposition,andnutritivevalueofsupplement,cornsilageand
bermudagrasspasture 133
4.3 Influenceofhousing(0800to1500honpastureorinbarnswithfansand
sprinklers),bST,andbSTwithsupplementalsilageonorganicmatterintake(OMI)
ofHolsteincowsgrazingTifton85bermudagrasspastures 146
4.4 Influenceofhousing(0800to1500honpastureorinbarnswithfansand
sprinklers),bST,andbSTwithsupplementalsilageonmilkproductionand
compositionofHolsteincowsgrazingTifton85bermudagrasspastures 151
4.5 CalculateddailyintakeofnutrientsbycowsgrazingTifton85bermudagrass(BG)
pasturesandnottreated(-bST)ortreated(+bST)withexogenousgrowthhormone.
Anadditionaltreatmenttestedtheeffectoffeedingcornsilage(Silage)tocows
treatedwithbST 153
4.6 Influenceofhousing(0800to1500honpastureorinbarnswithfansand
sprinklers),bST,andbSTwithsupplementalsilageonbodyweight(BW),body
conditionscore(BCS),respirationrates(RR),andconcentrationsofplasmainsulin
andinsulin-likegrowthfactor-1(IGF-1)ofHolsteincowsgrazingTifton85
bermudagrasspastures 156
viii
LISTOFFIGURES
Figure page
3.1 Interactionofforage[Tifton85bermudagrass(BG)orFlorigrazerhizomapeanut
(RP)]andyear(1995or1996)onproductionofmilk,4%fatcorrectedmilk(FCM),
andmilkfatandmilkfatpercent 92
3.2 Interactionofforage,stockingrate(SR),andyearonmilkand4%fatcorrectedmilk
(FCM) yieldsand bodyweightchange(DBW). ForageswereTifton85
bermudagrassandFlorigrazerhizomapeanut. LowandhighSRforBGwere5.0
and7.5cows/hain1995and7.5and10.0cows/hain1996. LowandhighSRfor
RPwere2.5and5.0cows/hain1995and5.0and7.5cows/hain1996 93
3.3 Interactionofsupplementationrateandforagespeciesonproductionofmilk,4%fat
correctedmilk(FCM),milkfat,andprotein. Supplementationrateswere0.33(Lo)
and0.5(Hi)kgofsupplementperkgofdailymilkproduction. Foragespecieswere
Tifton85bermudagrassandFlorigrazerhizomapeanut 95
3.4 Interactionofsupplementationrateandyearonproductionof4%fatcorrectedmilk
andmilkfat,andpercentagesofmilkfatandprotein. Low(Lo)andhigh(Hi)
supplementationrateswere0.33and0.5kgofsupplementper1kgofdailymilk
production,respectively 98
3.5 Interactionofparity,year,andsupplementationrateonproductionofmilk, 4%fat
correctedmilk(FCM),andmilkfatandmilkfatpercent. Low(Lo)andhigh(Hi)
supplementationrateswere0.33kgand0.5kgofsupplementperkgofdailymilk
production. Supplementationratesdidnotdifferbyyear(1995or1996) 99
3.6 Interactionofparity, forage,and stockingrateonbodyweightchange(ABW).
Averagelow(Lo)andhigh (Hi)stockingrateswere6.25and8.75cows/hafor
Tifton85bermudagrass (BG)and3.75and6.25 cows/ha forFlorigraze rhizoma
peanut (RP)pastures. Stockingrateswerethesameacrossparities 104
3.7 Interactionofsupplementationrateandyearonchangesofbodyconditionscore
(ABCS-5pointscale)andbodyweight(ABW). Low(Lo)and high(Hi)
supplementationrateswere0.33and0.5kgofsupplementperkgofdailymilk
production 104
ix
3.8 Interactionofforage,supplementationrate,andyearonbodyweightchange(ABW).
ForageswereTifton85bermudagrassandFlorgrazerhizomapeanut. Low(Lo)and
high(Hi)supplementationrateswere 0.33and 0.5kgofsupplementper1kgof
daily milk production. Supplementationratesdidnotdifferbyyear(1995or
1996) 106
3.9 Interactionsofparity,forage,andstockingrate(SR) onforageandtotalorganic
matterintake(OMI)and forageandtotalOMIasapercentofbodyweight
(OMIPBW). ForageswereTifton85bermudagrass(BG)orFlorigrazerhizoma
peanut(RP).Average lowandhigh SRforBGpastures were6.25and8.75
cows/ha. Average lowandhighSRforRPpastureswere3.75and6.25cows/ha.
112
4.1 VibracorderchartsforcowstreatedwithbSTandhousedinbarnsfrom0800to
1500h(A)andforcowshousedonpasture(B). Notethegreatergrazingintensity
forcowshousedinthebarnduringtheday 147
4.2 Effectofhousingonbodytemperaturesofcowsmeasuredovera24-hperiodand
averagedoverbSTtreatmentregimes 160
4.3 EffectofbSTonbodytemperaturesofcowsmeasuredovera24-hperiodand
averagedoverdaytimebarnanddaytimehousingregimes 162
4.4 Regressionequationestimatesofbodytemperaturesofcowsmeasuredovera24-h
periodandshowinginteractionofbST(+or-)andhousingtreatments 164
4.5 EffectofbarnplusbST(B+)vs.barnplusbSTplussilage(B+S)treatmentonbody
temperaturesofcowsmeasuredovera24-hperiod 165
x