Content uploaded by Martha Olivera-Angel
Author content
All content in this area was uploaded by Martha Olivera-Angel on Jul 30, 2018
Content may be subject to copyright.
Rev Colomb Cienc Pecu 2016; 29:77-90
Revista Colombiana de Ciencias Pecuarias
Original articles
77
Literature Review
Starch in ruminant diets: a review¤
Almidones en la alimentación de rumiantes: revisión de literatura
Amido na alimentação dos ruminantes: revisão de literatura
Luis M Gómez1,2,3*, MVZ, MSc, (c)Dr. Sc; Sandra L Posada2, Zoot, MSc, Dr. Sc; Martha Olivera3, MV, Dr. Sc.
1Departamento de Investigación y Desarrollo, Grupo Nutri-Solla, Solla S.A., AA 1272, Itagui, Colombia.
2GRICA Research Group, Facultad de Ciencias Agrarias, Universidad de Antioquia, AA 1226, Medellín, Colombia.
3BIOGENESIS Research Group, Facultad de Ciencias Agrarias, Universidad de Antioquia, AA 1226, Medellín, Colombia.
(Received: April 15, 2015; accepted: November 11, 2015)
doi: 10.17533/udea.rccp.v29n2a01
¤ Tocitethisarticle:GómezLM,PosadaSL,OliveraM.Starchinruminantdiets:areview.RevColombCiencPecu2016;29:77-90.
* Correspondingauthor: LuisM Gómez.Director ofResearch andDevelopment, SollaS.A. Company.Carrera42 No.33-80 Itagui,Colombia. Tel+574
4448411.E-mail:lmgomezo@solla.com
Summary
Background:starchisanimportantenergysourceforruminantsnutrition.Thiscarbohydrateisoftenused
toimproverumenfermentation,optimizingdigestionofstructuralcarbohydratesandincreasingproteinow
tothesmallintestine.Microbialanddigestiveenzymesareinvolvedinstarchdigestion,generatingproducts
thatcanpositivelyornegativelyaffectanimalperformanceandhealth,dependingonthestarchcontentsofthe
diet. Objective: todescribethebasiccharacteristicsofstarches,thefactorsaffectingitsnutritionalavailability,
anditseffectsinruminants.Conclusion:anumberoffactorsaffectstarchdigestibility,includinggranulesize,
amylose/amylopectinratio,proportionoffarinaceousandvitreous endosperm,presence ofstarch-lipidand
starch-proteincomplexes,andphysical-chemicalprocessingofthefeed.Ingestionoflargeamountsofstarch
cantriggerruminalacidosis.However,itsrationaluseinthediethaspositiveeffectsonmethaneemissions,
andinmilkyieldandcomposition.
Keywords: acidosis, amylopectin, amylose, digestibility, lactation, methanogenesis.
Resumen
Antecedentes: el almidónes unimportante recursoenergético parala alimentaciónde rumiantes.Este
carbohidratoesfrecuentementeempleadoparaelmejoramientodelosparámetrosdefermentaciónruminal,
loqueoptimiza elaprovechamiento de loscarbohidratos estructurales eincrementa elujode proteínaal
intestinodelgado.Ensudigestiónparticipanenzimasmicrobianasydigestivas,lascualesgenerandiferentes
78
Rev Colomb Cienc Pecu 2016; 29:77-90
Gómez LM et al. Starch in ruminant diets: a review
productosqueimpactanpositivaonegativamenteeldesempeñoproductivoylasaluddelanimal,dependiendo
del nivel de almidón en la dieta. Objetivo: describirlascaracterísticasbásicasdelosalmidones,losfactores
queafectansudisponibilidadnutricionalylosefectosdesuutilizaciónenlaalimentacióndelosrumiantes.
Conclusión:existeunsinnúmerodefactoresqueafectanladigestibilidaddelalmidón,entreellos,eltamaño
delgránulo,la relaciónamilosa/amilopéctina,laproporcióndeendospermofarináceoyvítreo,lapresencia
decomplejosconlípidosyproteínas,ysuprocesamientofísico-químico.Laingestióndegrandescantidades
dealmidónpuededesencadenaracidosisruminal;noobstante,suempleoracionalenladietadelosrumiantes
tieneefectospositivossobrelaemisióndemetano,ylaproducciónycalidaddelaleche.
Palabras clave: acidosis, amilopectina, amilosa, digestibilidad, lactancia, metanogénesis.
Resumo
Antecedentes: oamidoéuma importantefonte deenergianaalimentaçãodos ruminantes.Este carboidrato
é geralmente utilizado para melhorar os parâmetros de fermentação no rúmen, o que otimiza a utilização dos
carboidratosestruturaiseaumentao uxodeproteínaparao intestinodelgadodoanimal.Nasuadigestãoestão
envolvidas enzimas digestivas e microbianas, as quais geram diferentes produtos que impactam positiva ou
negativamenteodesempenhoprodutivoe asaúdedoanimaldependendo doníveldeamidona dieta.Objetivo:
descreverascaracterísticasbásicasdoamido,factoresqueafectamasuadisponibilidadenutricionaleosefeitosdasua
utilizaçãonaalimentaçãoderuminantes.Conclusão: diversosfatoresafetamadigestibilidadedoamido,incluindo
otamanhodogrânulo,arelaçãoamilose/amilopectina,aproporçãodeendospermafarináceoevítreo,aformação
decomplexoscomlipídeoseproteínaseoseuprocessamentofísico-químico.Aingestãodegrandesquantidades
deamidopodeprovocaracidoseruminal,noentanto,asuautilizaçãoracionalnaalimentaçãoderuminantestem
efeitospositivossobreasemissõesdemetano,aproduçãodeleiteeasuaqualidadecomposicional.
Palavras chave:acidose, amilopectina, amilose, digestibilidade, lactação, metanogênese.
Introduction
Starch–thelargestreservoirofplantpolysaccharides-
playsanimportantroleingerminationandgrowth,
anditssynthesisissecondonlytothatofcellulose.
Starchisthemainenergycomponentusedinruminant
feeds due to its availability (Ortega and Mendoza,
2003). It is often included in the diet to improve
ruminal fermentation, allowing for a better use of
structuralcarbohydratesandtoincreaseproteinow
tothesmallintestine(Huntingtonet al.,2006).Starch
sourcesare expensive,sotheymustbeusedwisely
tobecost-effective.Itisimportanttounderstandthe
structural characteristics of starch, its ruminal and
post-ruminal digestion and the factors affecting its
digestibility in order to improve performance and
prot of livestock systems. This review describes
starch,thefactorsaffectingitsnutritionalavailability,
anditseffectsinruminantfeedingandnutrition.
Description of starch
Composition
Starches are mainly α-glucans composed of
two types of molecules: amylose and amylopectin
(SantanaandMeireles,2014;Table1).Amyloseisa
linearD-glucosepolymercontainingabout99%α-1,4
links(Parker andRing,2001).Amylopectin,which
has95%α-1,4linksand5%α-1,6links(Stevneboet
al.,2006),isthemostabundantcomponentofstarches
(Figure 1). On the other hand, amylose content in
starchusuallyuctuatesfrom200to300g/Kg.Some
starch-richfeedssuchaswaxycerealsusuallycontain
negligibleamountsofamylose,whilehigh-amylose
sourcesmaycontainupto700gamylose/Kg.Cereals
suchaswheat,maize,barley,andricecancontaina
waxygenederivedfromnaturalmutationsofgenes
encoding granule bound starch synthase, which is
requiredforamylosesynthesis(Svihuset al.,2005).
Structure
Starchgranulesareformedbyconcentricallygrowing
layersalternatingsemi-crystallineandamorphouslms
(Figure1).Thesemi-crystallineregionismoreabundant
in amylopectin and is more impervious to enzymatic
attackbecauseofits resistance to entryofwater.The
amorphous region is rich in amylose and has lower
densitythanthecrystallinearea,whichfacilitateswater
ow and enzyme attack; however, it is abundant in
hydrogenbonds(Perezet al., 2009).
79
Rev Colomb Cienc Pecu 2016; 29:77-90
Gómez LM et al. Starch in ruminant diets: a review
Table 1. Properties of starch components.
Characteristic Component
Amylose Amylopectin
General structure Linear Branched
Branch sites Nonea1 per 20 to 25 glucose units
Polymerization degreeb
Molecular weight
~1.000
1 x 105-1 x 106 g/mol
~10.000-100.000
1 x 107-1 x 109 g/mol
Stability in solution Low High
a There is a type of branched amylose with 1 or 2 α-1,6 links per molecule.
b Number of glucose residues per molecule.
Adapted from Parker and Ring, 2001.
Figure 1. (A) Structure of starch granules, represented by organized laminar forms. Amorphous rings (composed mainly of amylose)
separate layers in the semi-crystalline regions (composed primarily of amylopectin). Modied from Perez et al., 2009. (B) Amylopectin
structure according with the cluster model by Myers et al., 2000. Glucan chains are depicted by solid lines while intersections between
them indicate branch linkages. The dotted lines show the limit of amylopectin side chain clusters with unbranched chains associated in
tightly packed double helices. a) depicts the amorphous areas separating amylopectin side chain clusters.
A
B
80
Rev Colomb Cienc Pecu 2016; 29:77-90
Gómez LM et al. Starch in ruminant diets: a review
Structural alterations
Gelatinization. It is the permanent alteration
of the granule structure by breaking its hydrogen
bonds. Starch absorbs water during gelatinization,
theexpansionbreaks the hydrogenbondsreleasing
someoftheamylosebyleaching,thusbirefringence
is reduced and starch becomes more soluble
and exposed to enzyme activity (Rooney and
Pugfelder,1986).Inexcessofwater,moststarches
gelatinise at temperatures higher than 80 °C. The
gelatinisationtemperatureishigherforsmallstarch
granules. Amylose-rich cereals are more resistant
togelatinisationthancereals with normal andhigh
amylopectin levels (Svihus et al., 2005). Table 2
shows gelatinization values for several foods and
processing methods. The degree of gelatinization
is higher for extruded vs. pelleted food since the
temperatureusedintheprocessishigher(upto250°C
vs.60-95°C;Caballero,2010).
Table 2. Starch gelatinization under several processing methods
in various feeds.
Food Gelatinization (%)1Processing
Corn 17.06 Unprocessed
Sorghum 12.47 Unprocessed
Yucca 7.59 Unprocessed
Concentrate 1 32.49 Pelleting
Concentrate 2 32.55 Pelleting
Concentrate 3 31.92 Pelleting
Corn 79. 3 Extruded
1Assessed by an enzymatic method (Medel et al., 1999).
Retrogradation. It is dened as the reversible
returnofasolubilized,dispersedoramorphousstate
toacrystallineorinsolubleform,whichlimitsstarch
digestibility. Amylose is the main component that
facilitatesretrogradation(Biliaderis,2009).
Sources of starch
Cereal grains and roots
Cerealgrainsare a major source of starch used
inanimalfeeds.Cereals are composed ofpericarp,
endosperm and germ (Figure 2). The pericarp
comprises3to8%ofthekernelweight,althoughit
canbeupto 25% in oats(Everset al.,1999).It is
mostlycomposed(90%)ofhighlyligniedberand
thestarchcontentislessthan10%(Liet al.,2007),
thuspericarpdigestibilitydoesnotexceed40%(Van
Barneveld,1999).
Figure 2.Corn kernel composition.Adapted from Eckhoff
andWatson(2009).
Theendospermrepresentsbetween60and90%of
thegrain.Itisthemorphologicalstructurecontaining
the starch. It also contains proteins, phospholipids
andash,butlittleneutraldetergentber(NDF)and
phosphorus (P; Eckhoff and Watson, 2009). The
endospermlayers,fromtheoutsidein,arealeurone,
peripheralendosperm,horny(orvitreous)andoury.
Boththeperipheraland the horny endospermhave
starch granules surrounded by a matrix abundant
in hydrophobic proteins called prolamines and
non-starch polysaccharides (PNAs; β-glucans,
arabinoxylans, and pectins), which are relatively
impermeabletowaterandenzymaticactivity(Zeoula
andCaldasNeto,2001;Giubertiet al.,2014).Grains
exhibitinghighproportion of peripheral and horny
endospermarecalledvitreousorhorny,whilethose
abundantinoury endosperm arecalledopaqueor
soft(ZeoulaandCaldasNeto,2001).
Non-conventional sources
Starchrepresentsanimportant fraction in many
crops.Mostcereals(i.e.corn, wheat, rice, oat, and
barley) contain between 60 and 80% starch, while
legumes (chickpea, bean, pea) contain from 25 to
81
Rev Colomb Cienc Pecu 2016; 29:77-90
Gómez LM et al. Starch in ruminant diets: a review
50%, tubers (potato, cassava, cocoyam, arrowroot)
from 60 to 90%, and some green fruit (banana,
mango) contain as much as 70% (Santana and
Meireles,2014).Asincereals,thelargestproportion
ofstarchcorrespondstoamylopectinandthesmallest
to amylose (17-30%; Hu et al., 2010). Amylose
represents14to19%ofstarchincassava,between2
and22%inpotato,andapproximately37%inplantain
(Knowleset al.,2012).Amylopectininstarchfrom
potatoislessbranchedcomparedtocereals(Alvani
et al.,2011).Itisalsohighlyexpandable(Vasanthan
andBhatty,1996) and gelatinizes atrelatively low
temperature(between64.4 and 69.9 °C) compared
tootherstarches(Hernandez-Medinaet al.,2008).
Table3showsamyloseandamylopectinconcentration
indifferentstarchyfoodsandconcentratesfedtodairy
cattle.Differencesinamylose/amylopectinratioaffect
therateofruminalorintestinaldigestion.Digestionrate
ofamylopectinis usuallyhigherthanthat of amylose
(Knowleset al.,2012).
Tab le 3. Amylose and amylopectin content in various feeds.
Source Amylose (%) Amylopectin (%)
Corn 29.24 70.76
Sorghum 29.55 70.45
Yucca 19.84 80.16
Concentrate 1 (C1)* 21.17 78.83
Concentrate 2 (C2) 22.22 77.78
Concentrate 3 (C3) 20.25 79.75
Concentrate 4 (C4) 24.89 75.10
*Isoenergetic and isoproteic concentrates (C) for dairy cattle formulated
with four carbohydrate sources: corn (C1), sorghum (C2), yucca (C3), citrus
pulp (C4). Assessed using the method described by Gibson et al. (1997).
Ruminal and post-ruminal digestion of starch
Once it reaches the rumen, starch is degraded
mainly by amylolytic bacteria and by fungi and
protozoato alesserextent(Huntington,1997).The
α-1-4andα-1-6endoandexoamylasesproducedby
rumenmicroorganismshavetheabilitytohydrolyze
amylose and amylopectin glycosidic linkages,
releasingdifferentoligosaccharides(Table4).
The post-ruminal process of starch degradation
begins with pancreatic α-amylase secretion, which
hydrolyzes amylose and amylopectin into dextrins
andlinearoligosaccharideswithtwotothreeglucose
units. The process is completed by the action of
oligosaccharidases(maltaseandisomaltase)secretedin
theintestinalmembrane(OrtegaandMendoza,2003).
Inruminants,thesite of starchdigestionaffects
thesubstratesabsorbed.Ruminaldigestiongenerates
volatilefattyacids(VFA)forabsorptionandprovides
energyformicrobialproteinsynthesis(Huhtanenand
Sveinbjörnsson,2006). Decreasedrumendigestibility
ofstarchisdesirabletopreventfromacidosisandto
increasethesupplyofglycogenicsubstrates(Svihus
et al.,2005). Starchdigestioninthesmallintestine
implies greater energetic efciency compared with
ruminaldigestionduetoreducedmethaneproduction
and fermentation heat losses and higher efciency
of metabolisable energy utilisation (Huhtanen and
Sveinbjörnsson, 2006). Nevertheless, the increased
energyefciencyfromhigherstarchdigestioninthe
small intestine is offset by the increase in hindgut
fermentation,becauseonlyVFAareabsorbedfrom
thehindgutwhereasmicrobialmatterisexcretedin
feces.Adecrease inruminalstarchdigestion isnot
associated with an increase in its small intestinal
Table 4. Enzymes involved in starch hydrolysis.
Enzyme Link End product
Phosphorylase α -1-4 glycosyl Glucose 1 phosphate
Alpha-amylase α -1-4 glycosyl Linear and branched oligosaccharides
Beta-amylase α -1-4 glycosyl Maltose and limit dextrins
Amyloglucosidase α -1-4 glycosyl and α -1-6 glycosyl Glucose
Isoamylase α -1-6 glycosyl Lineal chains of α -1-4 glucans
Pullulanase α -1-6 glycosyl Lineal chains of α -1-4 glucans
Adapted from Tester et al., 2004.
82
Rev Colomb Cienc Pecu 2016; 29:77-90
Gómez LM et al. Starch in ruminant diets: a review
digestion,butitisassociatedwithhigherhindgutand
lowertotaltractdigestibility(Larsenet al.,2009).
Forthisreason,rumenisconsideredtheprimary
site of starch digestion. Ruminal digestion usually
accountsfor 75to80% oftheintake, andabout35
to60%ofthestarch entering the small intestine is
degraded.About35to50%ofthestarchthatescapes
digestion in the small intestine is degraded in the
hindgut(Harson,2009).Accordingtoameta-analysis
byMoharreryet al.(2014),ruminalstarchdigestibility
variesgreatly(from 224to942 g/Kg).Theauthors
alsonotedthatstarchconsumptionadverselyaffected
ruminalstarchdigestibility,obtaininganegativeslope
of1.4%perKgincreaseindailystarchintake.Table
5 presents the content and ruminal digestibility of
various starch sources used in livestock.
Table 5. Starch content and ruminal digestibility of several starch
sources commonly used as feed supplements in dairy cattle.
Grain Starch (%) Rumen digestibility (%)a
Corn1,2 76.0 72 - 89.9
Sorghum1,2 71.3 60 - 78.4
Wheat1,2 70.3 88.3 - 88.1
Barley1,2 64.3 80.7 - 84.6
Oats1,258.1 92.7 - 94.0
Yucca380.0 91.0
a Variability is explained by grain treatment (grinding, rolling, aking).
1 Herrera-Saldana et al., 1990. 2Huntington, 1997. 3Vearsilp and Mikled, 2001.
Factors affecting starch digestibility
Granule size
Thisisalimitingfactorinstarchdigestionbecause
therelationship betweenstarchvolumeandsurface
area,andthussubstrate-enzymecontact,decreasesas
granulesizeincreases(Sviluset al.,2005).Cereals
withsmallgranules,suchasoatsandrice,aremore
digestiblethancorn, wheat andpotato,whichhave
longgranules(Bednaret al.,2001;Sviluset al.,2005).
Amylose/amylopectin ratio
Several studies have shown that amylose/
amylopectinratioisnegativelycorrelatedwithstarch
digestion(Bednaret al.,2001).Amyloseisinserted
intoamylopectinmoleculesincreasingtheamountof
hydrogen bonds within the starch molecule, which
negatively impacts the ability of expansion and
enzymeactivity(Caldas-Netoet al., 2000).Likewise,
starchgranuleswithhighamylosecontentaremore
pronetoretrogradation(Sviluset al.,2005).
Floury versus vitreous endosperm
Severalresearchers(Correaet al.,2002;Ngonyamo-
Majeeet al.,2008)havereportedaninverserelationship
betweenstarch digestibilityandvitreousness.Allen
et al.(2008),studiedruminalandduodenal-stulated
cows using corn with vitreous endosperm content
varyingbetween25and66%.Theyfoundthatfeeding
cornwith66%ofvitreousendospermreducedruminal
digestionin19.1%andoveralldigestionin7.1%.
Starch-lipid complexes
Quantitatively,lipids are the major non-starch
compoundsinstarchgranulesandcanbefoundas
freefattyacids(mostly palmiticandlinoleicacid)
and lysophospholipids (Svihus et al., 2005). In
cereal grains, a portion of amylose has insoluble
starch-lipidcomplexes,whichformhelicalstructures
that provide greater adhesion between molecules,
dininish starch swelling (Vasanthan and Bhatty,
1996), decrease their solubility (Rooney and
Pugfelder,1986)andreducetherateofenzymatic
digestion(Croweet al., 2000).Cassavaandpotato
starch contain a smaller percentage of lipids
compared with cereal starch (Zeoula and Caldas
Neto,2001;Alvaniet al.,2011).
Starch-protein complexes
The proteinaceous matrix surrounding starch
granulesaffectsstarchdigestibility.Digestibilityis
negativelyassociatedwiththepresenceofprolamins.
Prolaminsarestorageproteinsthatreceiveadifferent
nameforeach cereal,namelyzein(corn), karins
(sorghum), gliadin (wheat), hordeins (barley),
secalins(rice),andavenines(oats).Usually,wheat,
oats, rice and barley have fewer prolamins than
cornand sorghum(Momanyet al.,2006; Giuberti
et al.,2014).
83
Rev Colomb Cienc Pecu 2016; 29:77-90
Gómez LM et al. Starch in ruminant diets: a review
Zeinsaccountfor50to60%oftheproteininthe
wholegrainand are locatedattheperiphery of the
cell.Flouryendospermislowinzeincomparedwith
vitreous endosperm (Giuberti et al., 2014). Zeins
arenotsolubleintherumenenvironment(Lawton,
2002).Starchdigestionrequiresthatrumenbacteria
degradezeinsrstviaproteolysis,beforestartingthe
amylolyticactivity(Cotta,1998).
Processing of cereal grains
Grain processing using temperature, humidity
andpressurefacilitatebinding of bacteria tostarch
granules,increasingits digestibility (Huntington et
al., 2006). Common processing includes grinding,
pelleting, dry rolling, steam rolling (addition of
water before rolling), and steam aking. All these
processes aim to break grain barriers such as the
pericarp and the protein-starch matrix, allowing
accessof microorganismstostarchgranules.These
processesalsoreducetheparticlesize,andincrease
surfaceareaandmicrobialcolonization(Giubertiet
al., 2014). The response to processing varies with
differentgrains,withsorghum>corn>oats=barley>
wheat(Huntingtonet al.,2006).
Gelatinizationofstarchmakesitmorewater-soluble
anddigestible.AccordingtoHuntington(1997),steam
akingofcornimprovesruminal,post-ruminalandtotal
tractdigestibilitycomparedwithdryrolling(85vs.70%,
92vs.69%,and99vs.90%,respectively).According
toSveinbjörnssonet al.(2007),heattreatmentincreases
starchdegradationduring8hofin vitro incubation,as
follows:0.155vs.0.870forpurepotatostarch,0.491vs.
0.815forpeas,0.686vs.0.913forbarley,and0.351
vs.0.498formaize.
Only a fraction of starch is gelatinazed during
steamconditioningand pelleting offeeds(from10
to200gstarch/Kg).Theexpanderprocessing,onthe
otherhand,addsupto80gwater/Kgwhilethediet
reachesahighpressureandtemperaturesabove100°C,
thusresultinginbetween220and 350 g starch/Kg
gelatinizedduringthisprocess.The extrusion adds
evenmorewater(upto180gwater/Kg)andthediet
issubjectedto evenhighertemperatures(>110°C)
underhighpressure,thusresultinginmorecomplete
gelatinisation and disintegration of starch granules
(Svihus et al.,2005).ThiswasevidencedbyOffner
et al.(2003),whoreported0.607,0.663,0.743,0.746,
0.819, 0.830, and 0.867 effective degradabilities
foruntreated, cracked, ground, pelleted, expanded,
steamakedandextrudedcorn,respectively(passage
rate0.04h-1).Graintypealsoinuencestheresults.
Steamakingofcorneliminatedtheadverseeffects
ofvitreousendospermandprotein-starchmatrix on
digestibilityincomparisonwithdryrolling.Thiswas
contrary to the results obtained for barley, a grain
withahighlydigestibleprotein-starchmatrix,where
nodifferencewasobservedbetweenbothtreatments
(Engstromet al.,1992).
Starch source
The highest effective degradability of starch
in cereal grains was obtained for oats, wheat and
barley,being lower for corn and sorghum. Corn
and especially sorghum have a high proportion
of peripheral and horny endosperm resulting in
increased resistance to microbial activity (Rooney
andPugfelder,1986),unlikewheatandoats,which
have higher proportion of floury endosperm. In
addition, corn and sorghum have a denser protein
matrix(Kotarskiet al.,1992).Thein vitro experiment
byLanzaset al.(2007)measuredfractionalgasrates,
as a measure of starch digestion (Huhtanen and
Sveinbjörnsson,2006),reporting0.26,0.24,0.15,and
0.06h-1 ratesforwheat,barley,corn andsorghum,
respectively(p<0.001).
Cassavahashighereffectivedegradabilitythan
cornandsorghumduetoitslackofpericarp,protein
matrix,hornyandperipheralendosperm;aswellas
lowproportionoflipids,lackofassociationsbetween
starchandprotein,lessamylose,moreamylopectin,
lesshydrogenbonding,andgreaterswelling when
subjected to chemical processes. Cassava starch
is composed exclusively of amylopectin in the
crystalline region and amylose in the amorphous
region, which prevents excessive formation of
hydrogenbondswithamylopectin,allowingamylose
to be readily leached. This is contrary to cereals,
whichhaveamyloseinthecrystallineregion(Zeoula
andCaldasNeto,2001).Effectivedegradabilityof
corn,sorghumandcassava,reported by Offner et
al.(2003),was 0.597,0.603y0.802, respectively
(passagerate0.06h-1).
84
Rev Colomb Cienc Pecu 2016; 29:77-90
Gómez LM et al. Starch in ruminant diets: a review
Physiological restrictions of the small intestine
Starch digestibility in the small intestine is
limited.Asdigestaowincreases,starchdigestibility
decreases (Huntington et al., 2006). Factors that
limitstarchdigestibilityincludecontrolledglucose
absorption,decientenzymeaccessibilitytostarch
granules,alterationsinruminalandintestinalpH,and
lackofsynchronybetween starch ow throughthe
intestineandamylasesecretion(Owenset al.,1986).
Starchdigestion efciencyinthesmallintestine
variesbetweensources.Tothiet al.(2003)reported
higher digestibility for barley starch in the small
intestine compared with cornstarch, resulting in
higher small intestine absorption in terms of g/Kg
starchingested.
Starch and ruminal acidosis
Starchfermentationincreasesvolatilefattyacids
(VFA) and lactate production, which can reduce
ruminal pH and kill cellulolytic microorganisms,
leadingtodecreasedberdigestibilityanddrymatter
(DM) intake. Additionally, it can cause metabolic
disorders such as acute and sub acute ruminal
acidosis, rumenitis, laminitis, liver abscesses and
polyencephalomalacia(Plaizieret al.,2009).
The risk of ruminal acidosis increases when
starchdigestionrate increases.Thisratevaries with
graintypeandprocessingandgenerallyoccursinthe
followingorder:wheat(32%h)>oat>barley(29%h)
>potato(5%h)>corn(2%h)andsorghum(Callison
et al.,2001;Mosaviet al.,2012).Krauseet al.(2002)
reportedlowerruminalpHinlactatingcowsfedhigh
moisture corn vs. dried corn. Gulmez and Turkmen
(2007) observed a decrease of ruminal pH (<6) in
lactatingcowswhencornwasreplacedbywheat.They
alsoobservedlowpH(<5.8)over13continuoushours
whenwheatwastheonlysourceofstarch.
Cassavaisused asareadily fermentableenergy
source for ruminants. It has a high rate and extent
of ruminal degradation, as evidenced by Khampa
andWanapat(2006)whocomparedcassavavs.corn
supplementation at 1 and 2% of live weight. They
found that 2% cassava supplementation lowered
ruminalpH(5.3vs.6.4)andcellulolyticbacteria(2.3
vs.5.9x107).
Starch and methanogenesis
Ruminal digestion of ber-rich diets increases
hydrogen and carbon dioxide production, which
are substrates for methanogenesis. Moreover,
starch-rich diets change the bacterial ecology by
favoring propionic-acid producing bacteria over
methanogens (Bannink et al., 2006; Ellis et al.,
2008).Propionicacidproductionfromdicarboxylic
acids(aspartate,malate,fumarate)viathesuccinate
pathway is thermodynamically more efficient
than methanogenesis (Offner and Sauvant, 2006).
Moreover,rapidly-fermentingdietsreducemethane
productionbydecreasingruminalpH,whichaffects
thegrowthofmethanogens,protozoa (Hook et al.,
2011)andcellulolyticbacteria(Sunget al.,2007),
andincreasespassagerate,whichreducesprotozoans
and,thereby,interspecieshydrogentransfer(Kumar
et al.,2013).
Agle et al. (2010) reported that diets with higher
proportionofnon-structuralcarbohydrates(52and72%)
resultedinnumerically lowermethaneemissions(1.5
vs.3.4g/hour,respectively),althoughresultsshowed
nodifferenceduetohighvariability.Arecentstudyin
grazingHolsteinFriesiancowsfoundthatconcentrate
level (2, 4, 6, and 8 Kg/cow/day) had no impact on
methane emissions (287, 273, 272, and 277 g/day,
respectively). However, when it was associated with
DMandenergyconsumption,methanedecreasedwith
increasinglevelsofconcentrate(gCH4/KgDM:20,19.3,
17.7,and18.1;CH4-E/grossenergyintake:0.059,0.057,
0.053,and0.054,respectively).Theydemonstratedthat
concentratesupplementationtograzingcowsincreased
milkproductionanddecreasedmethaneemissionsper
unitofmilkproduced(Jiaoet al.,2014).Aguerreet
al.(2011)foundthatchangingforage:supplement
ratio(F/S)from68:32to47:53reducedmethane
emissionsfrom648to538g/cow/day.Pirondiniet
al.(2015)evaluatedtheeffectofstarch(23.7and
27.7%DM)onmethaneemissionsindairycows,
ndingloweremissionsforstarch-richdiets(415
vs. 396 g/d, respectively). Finally,Hatew et al.
(2015) investigated the effect of starch (270 vs.
530g/Kg concentrateDM)andfermentationrate
85
Rev Colomb Cienc Pecu 2016; 29:77-90
Gómez LM et al. Starch in ruminant diets: a review
(fastvs.slow)indairycows.Theyfoundnodifferences
inmethaneproducedperKgoffat-correctedmilkand
protein,orper KgDMconsumed, orasafraction of
thegrossenergyconsumed.However,thehighstarch
diet(46.9vs.43.1g/Kg)hadlessruminalmethane
per Kg of fermentable organic matter (42.6 vs. 47.4
g/Kg).Haleset al.(2012)evaluatedtheeffectofcorn
processing. They found that Jersey animals eating
steamedcornakesproducedlessmethanethanthose
eatingdryrolledcorn(58.77vs.74.31L/animal,11.65
vs. 14.06 L/KgDMintake,2.47 vs. 3.04% ofgross
energyconsumed,and3.30vs.4.18% of digestible
energ y consu med). The reduction was explained by
differences in ruminal fermentation, changi ng the
placeofdigestion(fromtherumentotheintestine),or
decreasedruminalpH.Scarceliteratureisavailableon
theeffectofstarchsourceandprocessingonmethane
emissions.InastudyreportedbytheCCRP(2012)a
reductionofmethaneemissionsincowsfedground
wheat(219gmethane/day,11.1gmethane/KgofDM
consumed)vs.groundcorn(424and19.5gmethane,
respectively).
The difference in methane production per starch
vs. cellulose unit does not depend on the chemical
composition,asboth carbohydratesarehydrolyzedto
glucosebeforefermentation.Conversely,hemicellulose
polymerincludessugarswith5to6carbons,whichcould
lead to changes in the fermentation prole (different
proportionsofVFA)andmethaneemissions.Ratherthan
thechemicalcomposition,thedifferences in methane
production from starch, cellulose and hemicellulose
appear to be a function of the microbial species that
degrade each substrate. Fermentation patterns and
methaneproductionvaryasmicrobialspeciesadaptto
changes in dietary substrates and ruminal conditions.
Additionally,associative effects between nutrients
inuence methane production, which means that this
gascanbeestimatedforthedietandnotforindividual
ingredients(Knappet al.,2014).
Relationship between starch and milk
composition and yield
Effect on milk yield and fat content
Milk yield response depends on the starch
source(Khorasaniet al.,2001) and its degradation
rate. Mosavi et al. (2012) compared milk yield in
Holstein cows consuming wheat, barley,maize or
potatoes. They found a reduced milk yield for the
diet added with potatoes, and attributed it to its
lower digestibility. Supplementation with rapidly
degradablestarchesinrumen-suchasbarley,wheat
or cassava- increases yield but reduces milk fat
(Sutton, 1989). Poore et al. (1993) found a milk
yieldincreaseof3.4Kg/dayand0.4%fatreduction
whenruminaldigestibilityincreasedfrom48to72%.
Milkfatreductionisassociatedwithchangesinthe
fermentationprole,causedbyarelativereductionin
lipogenicvs.glycogenicprecursors(Reynoldset al.,
1997).Rumenpropionateincreaseswhileacetateand
butyratedecreasewheningestionofrapidlydegradable
starchexceeds7Kg/day(Casperet al.,1990).Jurjanz
et al.(1998)evaluatedstarchsourceand level(wheat
orpotatopeels;<5,6,or>7.5Kg/d)onmilkyieldand
composition.Highstarchconsumptionfrom potato
peels(>7.5Kg/day)leadtoslowerruminaldegradation
andincreasedmilkfatcontent(+3.3g/Kg)compared
towheat.Fedinloweramounts,thestarchsourcedid
notaffectmilkfatsynthesis.Thelowerrateofstarch
degradationcouldhavereleasedmorefatprecursors.
Mosavi et al.(2012)alsoobservedslowerruminal
degradation for corn starch compared with wheat,
barley or potato, as well as increased acetate and
butyrateproductionalongwithhighermilkfat(3.43%
vs.3.12,3.09,and3.13%,respectively).Contraryto
thesendings,Chanjulaet al.(2004)didnotobserve
differences in milk production and compositional
qualitybyaddingcorn(lowdegradability)orcassava
(highdegradability)attwoinclusionlevels(55vs.
75%).
AccordingtoKennellyandGlimm(1998),milkfat
isreducedduetheinhibitoryeffectofmethylmalonyl
CoA(synthesizedfrompropionicacid)onfattyacid
synthesisinthemammarygland.MethylmalonylCoA
accumulation competitively inhibits malonyl CoA
(VanSoest,1994).
Reynoldset al.(1997)associatedmilkfatdecrease
withincreasedlevelsofplasmaglucoseandinsulin
in animals fed high amounts of the supplement.
Insulinlowerslipolysisandpromoteslipogenesisin
adiposetissue,reducingfattyacidsavailabilitytothe
mammarygland,thusdecreasingmilkfat.According
to Van Soest (1994), lipogenesis in adipose tissue
86
Rev Colomb Cienc Pecu 2016; 29:77-90
Gómez LM et al. Starch in ruminant diets: a review
is insulin dependent, which is not the case for the
mammarygland.
Thereductioninmilkfatcanalsobeexplainedby
increasedtrans-unsaturatedfattyacidsintherumen
(Gaynoret al.,1995).Cerealgrainsarehighinlinoleic
and oleic acid. A ruminal pH decrease due to the
dietcandisturbbiohydrogenationofunsaturated18
carbonfatty acidsincreasingtransC18:1fattyacid
(transisomersresultfromincompletemicrobialbio-
hydrogenationoflinoleicacidintostearicacid).Itis
knownthatruminalandmilkincreaseintransC18:1
iscorrelatedwithlowmilkfatlevelsincowsfedhigh
graindiets(Griinariet al.,1998).Corncontainsahigh
concentration of linoleic (C18:2) and octadecanoic
acid (trans C18:1),whichinhibit biohydrogenation
andreducelipogenesisinthemammarygland.
AccordingwithMontoyaet al.(2004),theoptimal
content of nonstructural carbohydrates (NSC) for
maximizingmilkyieldisbetween30and38%ofthe
diet. Those researchers supplemented cows with 4
Kgofacommercialconcentrateand0,6,and12Kg
offreshpotatoes,thusNSCaccountedfor7.2,12.4,
and17.9%ofDMintake.Milkyieldwashigherfor
the potato treatments (17.2 vs. 15.8 liters/cow/day;
p=0.004).Nevertheless,nodifferencewasobserved
fortheinclusionof6vs.12Kgpotatoes,whichcould
beassociatedwithalimitedabilitytousepotatoNSC.
Theirstudyfoundnodifferencebetweentreatmentsfor
fatpercentageand production(p>0.05).Pimentel et
al.(2006)alsoevaluatedcassavasupplementationon
milkyieldandcomposition.Theyreplaced0,25,50,
and75%ofcornwithcassava,ndingalineardecrease
of30and1.15g/dayinmilkyield(correctedfor3.5%
fat)andfatproduction,respectively.Accordingtothe
authors,theviabilityandlevelofcornsubstitutionwith
cassavawilldependonalowcostofsubstitutionthat
compensatesfortheexpecteddecreaseinproduction.
Dann et al. (2014) evaluated three starch levels
(17.7, 21.0, and 24.6%) in Holstein cows using
increasing levels of ground corn. They found that
solids-corrected milk yield was not affected by the
diet, averaging 40.8 Kg/d. They concluded that
starch content did not affect rumen fermentation or
performance.Theirhigheststarchlevel(onaDMbasis)
was between 23 to 30%, which follows within the
recommendedrangeforlactatingcows(Grant,2005).
Delahoyet al.(2003)conductedtwoexperiments
assuming that supplements such as steam-flaked
corn(SFC)andnon-forageber(NFF)sourcesmay
provide benets over corn. In the rst experiment,
animalswereassignedtoacracked-corn(CC)orto
asteam-akedcorn(SFC)supplement.Inthesecond
experiment,animalswereofferedgroundcorn(GC)
ornoforagesourcesofber(NFF).No differences
wereobservedinmilkyield(24.3and27.5Kg/dfor
experiments1and2,respectively),explainedbyalack
ofdifferenceinnetenergyconsumptionforlactation,
which exceeded the requirements (Experiment 1).
Anotherfactorthatcouldexplaintheseresultsisthe
qualityofthepasture,whichdidnotreducethepH,a
targettoimprovebyNFFinclusioninExperiment2.
Effect on the protein content
Dietsrichinnonstructuralcarbohydratesincrease
ruminalammonianitrogenutilizationandmicrobial
protein synthesis (Svihus et al., 2005). Therefore,
whendietaryenergyincreases,metabolizableprotein
is also increased. Mosavi et al. (2012) evaluated
theeffectof four starch sourcesonmilkproteinin
Holstein cows. While protein levels of milk were
similar (3.03, 3.10, 3.14, and 3.04%) for wheat,
barley,corn and potato supplements, respectively,
milkproteindifferedin favor of wheat, barley and
corn,comparedtopotato(1.08,1.06,1.06,and0.98
Kg/d,respectively; p=0.02).GozhoandMutsvangwa
(2008)foundnodifferenceinmilkproteinforanimals
feddietsbasedonwheat,barleyorcorn,buthigher
milk protein was observed for diets based on corn
vs. oats. On the contrary, other studies comparing
slowversusfastruminaldegradingstarchesfoundno
differencesin milkprotein(Khorasaniet al., 2001;
Silveira et al.,2007;Cabritaet al.,2009).
It has been suggested by Huhtanen and
Sveinbjörnsson(2006)thatenhancedstarchdigestion
in the small intestine increases milk protein,
perhapsbysparingaminoacidsfrombeingusedfor
gluconeogenesisintheliver.Theyreportastudyin
whichmilkproteinyieldwasslightlybutsignicantly
higherformaizecomparedwithbarleysupplements.
Contrarytothisconcept,increasingstarchdigestion
intherumenisconsideredadvantageousintermsof
milkproteinyield,sinceitincreasestheenergysupply
formicrobialproteinsynthesisandthemetabolisable
87
Rev Colomb Cienc Pecu 2016; 29:77-90
Gómez LM et al. Starch in ruminant diets: a review
protein ow to the small intestine (Thair, 2012).
Finally, Reynolds (2006) reports a study in which
therewasnoevidencethatthesiteofstarchdigestion
increasedmilkproductionorchangeditscomposition.
Final thoughts
Rumenfermentationofstarch-althoughitreduces
energy efciency over the enzymatic digestion in
the intestine- determines its nutritional value for
ruminants. The rate and extent of ruminal starch
digestion alters pH, cellulolytic activity, microbial
proteinsynthesis,methaneemissionsand,eventually,
animalproduction.Thereisa considerablebodyof
researchon degradation potential of various cereal
grains, but little information on non-traditional
sourcesofstarchthatcouldreplacecerealgrainswhen
availabilityandcostsarecompetitive.Thestructural
traitsofstarch fromthesesources,their interaction
withothercomponents,andtheeffectofprocessing
should be examined. In vitro digestion techniques
constituteastartingpointforstudyingtheextentand
kineticsofstarchdegradationfromnon-conventional
sources.
Starch is the main energy component used in
ruminants feed to modulate ruminal fermentation
andpromote sync with the nitrogen sources. More
researchisrequiredtoevaluatetheeffectofusingone
ormoresources of starch —with different degrees
of degradability and processing— on protein use
efficiency, milk yield and compositional quality.
Studiesshouldfocusonadditionlevelsandnutrient
composition of the forage base according with the
stage of lactation and energy requirements of the
animal.
Acknowledgements
The Administrative Department of Science,
TechnologyandInnovation(Colciencias,Colombia,
call 569 of 2012. Code 1115+569-33874) and
the Sustainability Strategy 2014-2015 (CODI,
UniversidaddeAntioquia,Colombia)supportedthe
research project entitled “Evaluación in vitro e in
vivodediversasestrategiasnutricionalesparamitigar
las emisiones de metano y su impacto productivo,
reproductivo y económico en ganadería de leche
especializadaenelnortedeAntioquia”,whichmade
possiblethisliteraturereview.
Conict of interest
Theauthorsdeclaretheyhavenoconictsofinterest
withregardtotheworkpresentedinthisreport.
References
Agle M, HristovAN, Zaman S, Schneider C, Ndegwa PM,
VaddellaVK.Effectofdietaryconcentrateonrumenfermentation,
digestibility,andnitrogenlossesindairycows.JDairySci2010;
93:4211-4222.
AguerreMJ,WattiauxMA,Powell JM, Broderick GA,Arndt C.
Effectofforage-to-concentrateratioindairycowdietsonemission
ofmethane,carbondioxide,andammonia,lactationperformance,
andmanureexcretion.JDairySci2011;94:3081-3093.
AllenMS,LonguskiRA,YingY.Endospermtypeofdryground
corngrainaffectsruminaland total tract digestion of starchin
lactatingdairycows.JDairySci2008;91(E-Suppl.1):529.
AlvaniK,QiX,TesterRF,SnapeCE.Physico-chemicalproperties
ofpotatostarches.FoodChem2011;125:958-965.
BanninkA,KogutJ,DijkstraJ,FranceJ,KebreabE,VanVuuren
AM,TammingaS.Estimationof the stoichiometry of volatile
fatty acid production in the rumen of lactating cows. J Theor
Biol2006;238:36-51.
Bednar GE, PatilAR, Murray SM, Grieshop CM, Merchen NR,
Fahey GC. Starch and ber fractions in selected food and feed
ingredientsaffecttheirsmallintestinaldigestibilityandfermentability
andtheirlargebowelfermentabilityinvitroinacaninemodel.JNutr
2001;131:276-286.
Biliaderis CG. Structural transitions and related physical
propertiesofstarch.In:BeMillerJ,WhistlerR,editors.Starch:
ChemistryandTechnology.3thed.AcademicPressUSA;2009.
p.293-372.
CaballeroDJ.Efectodelusodealimentobalanceadopeletizado
desdeelinicio hasta el engordeenlagranja porcina el Hobo,
SantaCruz deYojoa,Honduras.Tesisde pregrado.Zamorano,
Honduras. 2010; [Access date: March 9, 2015]. URL: http://
bdigital.zamorano.edu/bitstream/11036/236/1/T2917.pdf.
CabritaARJ,ValeJMP,BessaRJB,DewhurstRJ,FonsecaAJM.
Effectsofdietarystarchsourceandbuffersonmilkresponsesand
rumenfattyacidbiohydrogenationindairycowsfedmaize-based
diets.AnimFeedSciTechnol2009;152:267-277.
CaldasNetoSF,ZeoulaLM,BrancoAF,DoPradoIN,DosSantos
GT,FregadolliFL,KassiesMP,DalponteAO.Mandiocaeresíduos
dasfarinheirasnaalimentaçãoderuminantes:Digestibilidadetotal
eparcial.RevBrasZootec2000;29:2099-2108.
88
Rev Colomb Cienc Pecu 2016; 29:77-90
Gómez LM et al. Starch in ruminant diets: a review
Callison,SL,FirkinsJL,EastridgeML,HullBL.Siteofnutrient
digestion by dairy cows fed corn of different particle sizes or
steam-rolled.JDairySci2001;84:1458-1467.
CasperDP,SchingoetheDJ,EisenbeiszWA.Responseofearly
lactationdairycowsfeeddietsvaryinginsourceofnonstructural
carbohydrateandcrudeprotein.JDairySci1990;73:1039-1050.
ChanjulaP,WanapatM,WachirapakornC,RowlinsonP.Effect
ofsynchronizingstarchsourcesandprotein(NPN)intherumen
onfeedintake,rumenmicrobialfermentation,nutrientutilization
andperformanceoflactatingdairycows.AsianAustJAnimSci
2004;17:1400-1410.
CCRP,ClimateChangeResearchProgram.Effectofstarchbased
concentrateswithdifferentdegradationcharacteristicsonmethane
emissions.Reducingemissionsfromlivestockresearchprogram.
Australian Government, Department ofAgriculture, Fisheries
andForestry.2012.
Correa CES, Shaver RD, Pereira MN, Lauer JG, Kohn K.
Relationshipbetweencornvitreousnessandruminalinsitustarch
degradability.JDairySci2002;85:3008-3012.
CottaMA.Amylolyticof selected speciesof ruminal bacteria.
AppEnvironMicrobiol1998;54:772-776.
Crowe TC, Seligman SA, Copeland L. Inhibition of enzymic
digestionofamylose byfreefatty acidsin vitrocontributes to
resistantstarchformation.JNutr2000;130:2006-2008.
DannHM,TuckerHA,CotanchKW,KrawczelPD,MooneyCS,
GrantRJ,EguchiT.Evaluationoflower-starchdietsforlactating
Holsteindairycows.JDairySci2014;97:7151-7161.
Delahoy JE, Muller LD, Bargo F, Cassidy TW, Holden LA.
Supplementalcarbohydratesourcesforlactatingdairycowson
pasture.JDairySci2003;86:906-915.
EckhoffSR,WatsonSA.CornandSorghumstarches:Production.
In: BeMiller J, Whistler R, editors. Starch: Chemistry and
Technology.3thed.AcademicPressUSA;2009.p.373-439.
Ellis JL, Dijkstra J, Kebreab E, BanninkA, Odongo NE,
McBrideBW,FranceJ.Aspectsofrumenmicrobiologycentralto
mechanisticmodellingofmethaneproductionincattle.JAgricul
Sci2008;146:213e33.
Engstrom DF,Mathison GW,Goonewardene LA. Effect of
beta-glucan,starchandbercontentandsteamvsdryrollingof
barley-grainonitsdegradabilityandutilizationbysteers.Anim
FeedSciTechnol1992;37:33-46.
EversAD, O’Brien L, Blakeney AB. Cereal structure and
composition.AustJAgricRes1999;50:629-650.
GaynorPJ,WaldoDR,CapucoAV,ErdmanRA,DouglassLW,
TeterBB.Milkfatdepression,theglucogenictheoryandtrans-C
18:1fattyacids.JDairySci1995;78:2008-2015.
GibsonTS,Solah VA, McCleary BV.Aprocedureto measure
amylose in cereal starches and ours with concanavalinA. J
CerealSci1997;25:111-119.
Giuberti G, GalloA, Masoero F, Farraretto LF, Hoffman PC,
ShaverRD.Factors affectingstarch utilization inlarge animal
foodproductionsystem:Areview.Starch2014;66:72-90.
GozhoGN,MutsvangwaT.Inuenceofcarbohydratesourceon
ruminalfermentationcharacteristics,performance,andmicrobial
proteinsynthesisindairycows.JDairySci2008;91:2726-2735.
Grant,R.2005.Optimizingstarchconcentrationsindairyrations.
ProcTri-StateDairyNutrConf,FortWayne,IN,2005.p.73-79.
GriinariJM,DwyerDA,McGuierMA,BaumanDE,Palmquist
DL, Nurmela KV. Trans- octadecenoic acids and milk fat
depressionin lactatingdairy cows.J DairySci 1998;81:1251-
1261.
GulmezBH,TurkmenII.Effectofstarchsourceswithdifferent
degradationratesonruminalfermentationoflactatingdairycows.
RevueMédVét2007;158:92-99.
HalesKE,ColeNA,MacDonaldJC.Effectsofcornprocessing
methodanddietaryinclusionofwetdistillersgrainswithsolubles
on energy metabolism, carbon-nitrogen balance, and methane
emissionsofcattle.JAnimSci2012;90:3174-3185.
Hatew B, Podesta SC, Van Laar H, Pellikaan WF,Ellis JL,
DijkstraJ,BanninkA.Effectsofdietarystarchcontentandrate
offermentationonmethaneproductioninlactatingdairycows.
JDairySci2015;98:486-499.
HarsonDL.Understandingstarchutilizationinthesmallintestine
ofcattle.Asian-AustJAnimSci2009;22:915-922.
Hernández-Medina M, Torruco-Uco JG, Chel-Guerrero L,
Betancur-AnconaD.Caracterizaciónsicoquímicadealmidones
de tubérculos cultivados en Yucatán, México. Cienc Tecnol
Aliment2008;28:718-726.
Herrera-Saldana R, Huber TJ, Poore MH. Dry matter, crude
protein,andstarchdegradability of ve cereal grains. JDairy
Sci1990;73:2386-2393.
Hook SE, Steele MA, Northwood KS, WrightAD, McBride
BW.Impactofhigh-concentratefeedingandlowruminalpHon
methanogensandprotozoa intherumenofdairycows.Microb
Ecol2011;62:94-105.
Hu G, Burton C, Yang C. Efcient measurement of amylose
contentincerealgrains.JCerealSci2010;51:35-40.
Huhtanen P, Sveinbjörnsson J. Evaluation of methods for
estimatingstarchdigestibilityanddigestiónkineticsinruminants.
AnimalFeedSciTechnol2006;130:95-113.
HuntingtonGB.Starchutilizationbyruminants:frombasicsto
thebunk.JAnimSci1997;75:852-867.
HuntingtonGB,HarmonDL,RichardsCJ.Sites,rates,andlimits
ofstarchdigestionandglucosemetabolismingrowingcattle.J
AnimSci2006;84:E14-E24.
Jiao HP, Dale AJ, Carson AF, Murray S, GordonAW, Ferris
CP.Effectofconcentratefeedlevelonmethaneemissionsfrom
grazingdairycows.JDairySci2014;97:7043-7053.
89
Rev Colomb Cienc Pecu 2016; 29:77-90
Gómez LM et al. Starch in ruminant diets: a review
JurjanzS,Colin-SchoellenO,GardeurJN,LaurentF.Alterationof
milkfatbyvariationinthesourceandamountofstarchinatotal
mixeddietfedtodairycows.JDairySci1998;81:2924-2933.
Kennelly JJ, Glimm DR. The biological potential to alter the
compositionofmilk.CanJAnimSci1998;78(Suppl):23.
KhampaS,WanapatM.Inuencesofenergysourcesandlevels
supplementationonruminalfermentationandmicrobialprotein
synthesisindairysteers.PakistanJNutrition2006;5:294-300.
KhorasaniGR,Okine EK,KennellyJJ. Effectsofsubstituting
barleygrain withcorn onruminal fermentationcharacteristics,
milkyieldandmilkcompositionofHolsteincows.JDairySci
2001;84:2760-2769.
KnappJR,LaurGL,VadasPA,WeissWP,TricaricoJM.Enteric
methaneindairycattleproduction:Quantifyingtheopportunities
andimpact of reducingemissions. JDairySci 2014;97:3231-
3261.
KnowlesMM,PabonML,CarullaJE.Useofcassava(Manihot
esculenta Crantz) and other starchy non-conventional sources
inruminantfeeding.RevColomCiencPecu2012;25:488-499.
KotarskiSF,WaniskaRD,ThurnKK. Starchhydrolisis bythe
rumenmicroora.JNutr1992;122:178-190.
Krause KM, Combs DK, Beauchemin KA. Effects of forage
particlesize andgrainfermentabilityinmid-lactationcows.II.
RuminalpH andchewing activity.JDairy Sci2002; 85:1947–
1957.
Kumar S, Dagar SS, PuniyaAK, Upadhyay RC. Changes in
methaneemission, rumen fermentationin responsetodiet and
microbialinteractions.ResVetSci2013;94:263-268.
LanzasC,FoxDG,PellAN.Digestionkinetics ofdriedcereal
grains.AnimFeedSciandTechnol2007;136:265-280.
LarsenM, LundP,WeisbjergMR,HvelplundT.Digestionsite
ofstarchfromcerealsandlegumesinlactatingdairycows.Anim
FeedSciandTechnol2009;153:236-248.
LawtonJW.Zein:Ahistoryofprocessinganduse.CerealChem
2002;79:1-18.
Li L, Blanco M, Jane JL. Physicochemical properties of
endosperm and pericarp starches during maize development.
CarbohydrPolym2007;67:630-639.
Medel P, Salado S, de Blas JC, Mateo GG. Processed cereals
indietsforearly-weanedpiglets.AnimalFeedSciandTechnol
1999;82:145-156.
MoharreryA,LarsenM,WeisbjergMR.Starchdigestioninthe
rumen, small intestine, and hind gut of dairy cows –A meta-
analysis.AnimFeedSciTechnol2014;192:1-14.
MomanyFA,SessaDJ,LawtonJW,SellingGW,HamakerSA,
WilletJL. Structural characterization of alpha-zein.J Agric
FoodChem2006;54:543-547.
MontoyaNF,PinoID,CorreaHJ.Evaluacióndelasuplementación
con papa (Solanum tuberosum) durante la lactancia en vacas
holstein.RevColCiencPec2004;17:241-249.
MosaviGHR, FatahniaF,MirzaeiAlamoutiHR,MehrabiAA,
DarmaniKohH.Effectofdietarystarchsourceonmilkproduction
andcompositionof lactatingHolsteincows. SAfr JAnim Sci
2012,42:201-209.
MyersAM,MorellMK,JamesMG, BallSG. Recentprogress
toward understanding biosynthesis of the amylopectin crystal.
PlantPhysiol2000;122:989-997.
Ngonyamo-MajeeD,ShaverRD,CoorsJG,SapienzaD,Lauer
JG. Relationship between kernel vitreousness and dry matter
degradability for diverse corn germplasm. II.Ruminal and
post-ruminal degradabilities. Anim Feed Sci Technol 2008;
142:259-274.
OffnerA, Bach A, Sauvant D. Quantitative review of in situ
starchdegradationintherumen.AnimFeedSciTechnol2003;
106:81-93.
OffnerA, Sauvant D. Thermodynamic modeling of ruminal
fermentations.AnimRes2006;55:343-365.
OrtegaME,MendozaG.Starchdigestionandglucosemetabolism
intheruminant:areview.Interciencia2003;28:380-386.
Owens FN, Zinn RA, KimYK. Limits to starch digestion in
theruminant’ssmallintestine.JAnimSci1986;63:1634-1648.
ParkerR,RingSG.Aspectsofthephysicalchemistryofstarch.
JCerealSci2001;34:1-17.
PerezS, BaldwinPM,GallantDJ.Structuralfeaturesof starch
granulesI.In:BeMillerJ,WhistlerR,editors.Starch:Chemistry
andTechnology.3thed.AcademicPressUSA;2009.p.149-192.
PimentelRR,AndradeFM,ChavesAS,deLimaLE,RamosVR.
Substituição do milho pela raspa de mandioca em dietas para
vacasprimíparasemlactação.RBrasZootec2006;35:1221-1227.
Pirondini M, Colombini S, Mele M, Malagutti L, Rapetti L,
GalassiG,CrovettoGM.Effectofdietarystarchconcentration
andshoilsupplementationonmilkyieldandcomposition,diet
digestibility,and methaneemissionsin lactating dairy cows.J
DairySci2015;98:357-372.
Plaizier JC, Krause DO, Gozho GN, McBride BW. Subacute
ruminalacidosisindairycows:thephysiologicalcauses,incidence
andconsequences.VetJ2009;176:21-31.
PooreMH,MooreJA,SwingleRS,EckTP,BrownWH.Response
oflactatingHolstein cowstodiets varying inbersource and
ruminalstarchdegradability.JDairySci1993;76:2235-2243.
ReynoldsCK.Productionandmetaboliceffectsofsiteofstarch
digestionindairycattle.AnimFeedSciTechnol2006;130:78-94.
ReynoldsCK,SuttonJD,BeeverDE.Effectsoffeedingstarch
to dairy cattle on nutrient availability and production. In:
GarnsworthyPC,WisemanJ,editors.Recentadvancesinanimal
nutrition Nottingham University Press. Nottingham 1997. p.
105-134.
RooneyLW,PugfelderRL.Factorsaffectingstarchdigestibility
withspecial emphasison sorghumandcorn.JAnimSci1986;
63:1607-1623.
90
Rev Colomb Cienc Pecu 2016; 29:77-90
Gómez LM et al. Starch in ruminant diets: a review
SantanaA,MeirelesA.New starchesarethetrendforindustry
applications:areview.FoodandPublicHealth2014;4:229-241.
SilveiraC,Oba M, BeaucheminKA, Helm J.Effectof grains
differinginexpectedruminalfermentabilityontheproductivity
oflactatingdairycows.JDairySci2007;90:2852-2859.
Stevnebo,SahlstromS,SvihusB.Starchstructureanddegreeof
starchhydrolysisofsmallandlargestarchgranulesfrombarley
varietieswithvaryingamylosecontent.AnimFeedSciTechnol
2006;130:23-38.
SungHG,KobayashiY,ChangJ,HaA,HwangIH,HaJK.Low
ruminalpHreducesdietaryberdigestionviareducedmicrobial
attachment.Asian-AustJAnimSci2007;20:200-207.
Sutton JD.Altering milk composition by feeding. J Dairy Sci
1989;72:2801-2814.
SveinbjörnssonJ,MurphyM,UdénP.Invitroevaluationofstarch
degradationfromfeedswithorwithoutvariousheattreatments.Anim
FeedSciTechnol2007;132:171-185.
Svihus B, UhlenAK, Harstad OM Effect of starch granule
structure, associated components and processing on nutritive
valueofcerealstarch:Areview.AnimFeedSciTechnol2005;
122:303-320.
TesterRF,KarkalasJ,QiX.Starchstructureanddigestibilityenzyme-
susbstraterelationship.WorldsPoultSciJ2004;60:186-195.
ThairMN.Effectsofthelevel,typeandprocessingofcerealgrains
indietsfordairycows.DoctoralThesis.SwedishUniversityof
AgriculturalSciences,2012;[Accessdate:September4,2015].
URL:http://pub.epsilon.slu.se/8984/1/tahir_mn_120823.pdf
TothiR,LundP,WeisbjergMR,HvelplundT.Effectofexpander
processing on fractional rate of maize and barley starch
degradationintherumenofdairycows estimatedusingrumen
evacuationand insitutechniques.Anim FeedSci andTechnol
2003;104:71-94.
VanBarneveldSL.Chemicalandphysicalcharacteristicsofgrains
related to variability in energy and amino acid availability in
ruminant:areview.AustJAgricRes1999;50:651-666.
VanSoestPJ.Nutritionalecologyoftheruminant.2thed.O&B
Books,Corvalis;1994.
VasanthanT,BhattyRS.Physicochemicalpropertiesofsmall-and
large-granulestarchesofwaxy,regularandhighamylosebarleys.
CerealChem1996;73:199-207.
VearsilpT,MikledC.Siteandextentofcassavastarchdigestion
inruminants.InternationalWorkshoponCurrentResearchand
Developmenton UseofCassavaasAnimalFeed. KhonKaen,
UniversityThailand2001; [Accessdate:March9,2015] URL:
http://www.mekarn.org/procKK/choc.htm
Zeoula LM, Caldas Neto SF.Recentes avanços em amido
na nutrição de vacas leiteiras. In: Simposio Internacional em
bovinoculturadeleite.AnaisLavras2001:Lavras:Universidad
FederaldeLavrasp.249-84