Influence of genotype on in vitro dry matter disappearance rate, estimated microbial yield and in vivo
digestive physiology of barley
by Ruth Ellen Kemalyan
A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in
Animal Science
Montana State University
© Copyright by Ruth Ellen Kemalyan (1991)
Abstract:
Effects of genotypic variation among barley cultivars were evaluated under in vitro and in vivo. In vitro
dry matter disappearance rate and estimated microbial yield (as measured by purine accumulation) was
measured using one normal barley (Cl 15478), 5 proanthocyanidin-free mutant cultivars (ANT 534,
ANT 563, ANT 230, ANT 231, ANT 246) and 2 cross-line barleys (CA 602914, CA 57163). Four
cultivars were selected for use in a sheep metabolism study. Cultivars were analyzed for starch, protein,
neutral detergent fiber (NDF), fiavonoid and total phenolic compounds and $ -glucan content.
Correlation coefficients were calculated between the chemical constituents, DMDR and purine
accumulation. Cultivars differed (P<.05) with respect to DMDR and purine accumulation. Negative
relationships (P<.05) were detected between DMDRand starch (r=-.44), fiavonoid compounds (r=-.30)
and phenolic compounds (r=-.31). Purine accumulation was positively associated with protein content
(r=.30) and NDF (r=.46) and negatively with starch (r=-.38), fiavonoid compounds (r=-.32), phenolics
(r=-.37) and $ glucan (r=-.29). The metabolism study investigated one normal barley, (Cl 15478), 3
proanthocyanidin-free mutant cultivars (ANT 534, ANT 246, ANT 231) and com. Diets were
formulated to provide equal starch, protein and NDF. The diets were fed to mature ruminally and
duodenally cannulated Rambouillet ewes in a 5 X 5 Latin square design. Ruminal diy matter and
organic matter digestibility in ewes was affected by diet (P<.05). Viscosity and pH of ruminal fluid
were similar in all ewes. Ruminal viscosity appeared to be inversely related to $ -glucan content of the
grain. Ruminal and duodenal NH3 concentrations were similar in ewes fed all diets. The ruminal
digestion of starch (P<.01) and duodenal starch flow (P<.05) in ewes was influenced by diet. Effects of
diet fed to ewes were found in duodenal CP flow (P<.05), dietary escape protein flow (P<.01) with
dietary escape protein flow greater (P<.01) in ewes fed com. Microbial nitrogen concentration in the
duodenum were similar in ewes fed each diet. Microbial efficiencies differed (P<.05) in ewes fed the
various diets with values ranging from 13.3 to 21.4 g microbial protein produced/100 g OM digested.
Results from this study demonstrate variation among lines of barley for in vitro DMDR and estimated
microbial yield. These results also demonstrate genotypic variation among barley cultivars site and
extent of digestion. INFLUENCE OF GENOTYPE ON IN VITRO DRY MATTER
DISAPPEARANCE RATE, ESTIMATED MICROBIAL YIELD AND
IN VIVO DIGESTIVE PHYSIOLOGY OF BARLEY
by
R uth Ellen Kemalyan
A thesis subm itted in p artial fulfillm ent
o f th e requirem ents for th e degree
of
M aster o f Science
in
Animal Science
MONTANA STATE UNIVERSITY
Bozeman, M ontana
April, 1991
/U ir f
i i
/ail
APPROVAL
o f a thesis subm itted by
R uth Ellen Kemalyan
This thesis has been read by each m em ber of th e thesis com m ittee and has
been found to be satisfactory regarding content, English usage, form at, citations,
bibliographic style, and consistency, and is ready for subm ission to th e College of
G raduate Studies.
s / z R 131
Date
Chairperson, G raduate C om m ittee
Approved for the M ajor D epartm ent
y r zL
Head, M ajd f D epartm ent
A pproved for the College o f G raduate Studies
/r, / ? ? /
Date
G raduate D ean
STATEMENT OF PERMISSION TO USE
In presen tin g this thesis in p artial fulfillm ent o f th e requirem ents fo r a
m a ster’s degree a t M ontana State University, I agree th a t th e Library shall m ake it
available to borrow ers u n d e r rules o f th e Library. Brief q u o tatio n s from this thesis
are allow able w ith o u t special perm ission, provided th a t accurate acknow ledgm ent
o f source is m ade.
Perm ission for extensive q uo tatio n from o r rep ro d u ctio n o f this thesis m ay
be g ran ted by m y m ajor professor, o r in his absence, by th e D ean o f Libraries w hen,
in th e opinion o f either, th e proposed use o f th e m aterial is fo r scholarly purposes.
Any copying o r use o f th e m aterial in this thesis for financial gain shall n o t be
allow ed w ith o u t m y W ritten perm ission.
D ate
Si
:
if 9 /
0
ACKNOWLEDGMENTS
The funding for this project w as provided b y th e M ontana W heat and B arley
C om m ittee.
I am grateful to th e C om m ittee for th e o p p o rtu n ity to fu rth er m y
education an d I tru s t th a t th e know ledge gained as a resu lt o f this endeavor w ill be
equal to th e benefits I have received.
The com pletion o f this project could n o t have b een achieved w ith o u t th e
su p p o rt o f m any people. First, I th a n k m y paren ts, A rthur a n d Ju n e Kemalyan, an d
m y fam ily w hose encouragem ent and faith in m e have n ev er w avered. To M ark
Petersen I extend a special thanks for his patience and efforts o n m y behalf. I th a n k
D rs. W alt N ew m an, Verl Thom as and Charles McGuire fo r serving o n m y g rad u ate
com m ittee. I am grateful to Connie Clark an d N ancy R oth a t th e N utrition C enter
for th e ir train in g an d help. Finally, to m y fellow g rad u ate stu d en ts I extend m y
sincere appreciation for th e w arm friendships, th e m oral su p p o rt and the v o lu n teer
tim e you offered to m e. I w ould n o t have m ade it w ith o u t you.
V
TABLE OF CONTENTS
LIST OF T A B L E S ..................................................................................................................
A B S T R A C T ........................................................................
1. INTRODUCTION ....................................................................................................... : .
vi
viii
I
2. LITERATURE REVIEW .................................................................................................. 3
B arley as a Feed G rain for R um inants ............................................................ 3
C ultivar effects o n p e r f o r m a n c e ......................................................................... 4
Physical an d Chem ical C haracteristics o f B a r le y ............................................ 5
Physical C h a ra c te ris tic s ......................................................
5
Chem ical C h a r a c te ris tic s ...........................................
5
S t a r c h ..............................................................
5
F i b e r ............................................................................................ .. . 7
B eta-glucan .................................................................................... 8
P rotein ............................................................................................ 9
Phenolic c o m p o u n d s .................................................................
11
3. MATERIALS AND METHODS .................................................................................
In V itro E v a lu a tio n ........................................................................................... .
M etabolism Study .....................................
Statistical Analysis ...............................................................................................
In Vitro Study ...........................................
M etabolism S tu d y ...................................................................
13
13
15
18
18
18
4. RESULTS AND D ISCU SSIO N .............................
In V itro S t u d y ........................................................
M etabolism Study ...............................................................................................
20
20
24
5. CONCLUSIONS .............................................................................................................
38
LITERATURE CITED
42
APPENDIX
......................................................
48
Vl
LIST OF TABLES
Table
1. CHEMICAL COMPONENTS OF NORMAL, PROANTHOCYANIDIN-FREE
AND CROSS-LINE B A R L EY S............................................................................
2.
THE INFLUENCE OF BARLEY CULTIVAR ON DRY MATTER
DISAPPEARANCE RATE (DMDR) AND PURINE YIELD IN BARLEY
DURING IN VITRO FERMENTATION......................................................
14
20
3. CORRELATION OF CHEMICAL CONSTITUENTS OF BARLEY WITH DRY
MATTER
DISAPPEARANCE
RATE
AND
PURINE
ACCUM ULATION..................................................................................................
22
4. COMPOSITION OF TREATMENT DIETS (% AS FED)
_________ ________
25
5. CRUDE PROTEIN (CP), STARCH AND NEUTRAL DETERGENT FIBER
(NDF) CONTENT OF TREATMENT DIETS ( % ) .........................................
25
6. DAILY INTAKE (G) OF DRY MATTER (DM), ORGANIC MATTER
(O M ), STARCH, CRUDE PROTEIN (CP) AND NEUTRAL
DETERGENT FIBER ( N D F ) ...............................................................................
26
7. INFLUENCE OF TREATMENT DIET ON PERCENT RUMINAL
DIGESTION AND DUODENAL FLOW OF DRY MATTER (DM) AND
ORGANIC MATTER ( O M ) .................................................................................
26
8. INFLUENCE OF TREATMENT DIET ON RUMINAL FLUID VISCOSITY
AND TOTAL BETA-GLUCAN C O N T E N T ................................................... .
28
9. EFFECT OF DIET ON IN SITU DIGESTIBILITY OF BARLEY
CULTIVARS AND C O R N ..............................................................
29
10. EFFECTS OF TREATMENT DIET ON RUMINAL STARCH DIGESTION
AND STARCH FLOW TO THE DUODENUM .............................. ................
30
11.
EFFECTS OF TREATMENT DIETS ON RUMINAL AND DUODENAL
AMMONIA (NH3) CONCENTRATION (M G /100 M L ) ..............................
32
12. EFFECTS OF TREATMENT DIETS ON DAILY FLOW OF CRUDE
PROTEIN (CP), ESCAPE PROTEIN (ESCP) AND MICROBIAL
CRUDE PROTEIN (MCP) TO THE SMALL INTESTINE..................... ........... 35
VU
LIST OF TABLES CONTINUED
Table
13. EFFECTS OF TREATMENT DIET ON MICROBIAL EFFICIENCY
(MOEFF) (g MICROBIAL PROTEIN PRODUCED/lOO g ORGANIC
MATTER DIGESTED) . .......................................................................................36
14. ARRANGEMENT OF BARLEY CULTIVARS IN VITRO FERMENTATION
RUN SCHEDULE ....................................................................................................48
15. LEAST SQUARES ANALYSIS OF VARIANCE FOR RUMEN
DIGESTIBILITY OF DRY MATTER AND ORGANIC M A T T E R ................
48
16. LEAST SQUARES ANALYSIS OF VARIANCE FOR DRY MATTER AND
ORGANIC MATTER FLOW TO THE DUODENUM ...................................
49
17. LEAST SQUARES ANALYSIS OF VARIANCE FOR PH A N D .
VISCOSITY OF RUMEN FLUID IN EWES ........................... ........................
49
18. LEAST SQUARES ANALYSIS OF VARIANCE FOR RUMINAL STARCH
DIGESTION AND STARCH FLOW TO THE DUODENUM ......................
49
19. LEAST SQUARE ANALYSIS OF VARIANCE FOR FLOW OF CRUDE
PROTEIN AND ESCAPE PROTEIN TO THE D U O D E N U M ......................
50
20. LEAST SQUARES ANALYSIS OF VARIANCE FOR FLOW OF
MICROBIAL NITROGEN TO THE DUODENUM AND MICROBIAL
EFFICIENCY ........................... ........................................................................... ..
50
21. LEAST SQUARES ANALYSIS OF VARIANCE FOR CONCENTRATION
OF RUMINAL AMMONIA AND DUODENAL A M M O N IA ........................
50
22. LEAST SQUARES ANALYSIS OF VARIANCE FOR IN VITRO DRY
MATTER DISAPPEARANCE RATE (DMDR) AND IN VITRO PURINE
YIELD OF BARLEY CULTIVARS ....................................................................
51
V lll
ABSTRACT
Effects o f genotypic v ariatio n am ong b arley cultivars w ere ev alu ated u n d er in v itro
an d in vivo. In vitro dry m a tte r disappearance ra te and estim ated m icrobial yield
(as m easured by purine accum ulation) w as m easured using o ne n orm al barley (Cl
1 5 478), 5 proanthocyanidin-free m u ta n t cultivars (ANT 534, ANT 563, ANT 230,
ANT 231, ANT 2 46) and 2 cross-line barleys (CA 6 0 2 9 1 4 , CA 5 7 1 6 3 ). Four
cultivars w ere selected for use in a sheep m etabolism study. Cultivars w ere
analyzed fo r starch, protein, n eu tral d eterg en t fiber (NDF), fiavonoid and to ta l
phenolic compounds and $
-glucan content. Correlation coefficients were calculated
betw een th e chem ical constituents, DMDR an d purine accum ulation. Cultivars
differed ( P c .05) w ith respect to DMDR and purine accum ulation. N egative
relationships ( P c .05) w ere detected b etw een D M DRand starch (r= -.4 4 ), fiavonoid
com pounds (r= -.3 0 ) and phenolic com pounds (r= -.3 1 ). Purine accum ulation w as
positively associated w ith p ro tein co n ten t (r= .3 0 ) and NDF (r= .4 6 ) and negatively
w ith starch (r= -.3 8 ), fiavonoid compounds (r= -.3 2 ), phenolics (r= -.3 7 ) and $
glucan (r= -.2 9 ). The m etabolism stu d y investigated one n o rm al barley, (Cl 154 7 8 ),
3 proanthocyanidin-free m u ta n t cultivars (ANT 534, ANT 246, ANT 231) and com .
Diets w ere form ulated to provide equal starch, p ro tein and NDF. The diets w ere fed
to m atu re rum inally an d duodenally can n u lated R am bouillet ew es in a 5 X 5 Latin
square design. R um inal d iy m a tte r and organic m a tte r digestibility in ew es w as
affected by diet ( P c .05). Viscosity and pH o f rum inal fluid w ere sim ilar in all ew es.
Ruminal viscosity appeared to be inversely related to $
-glucan content of the grain.
R um inal an d duodenal NH3 concentrations w ere sim ilar in ew es fed all diets. The
rum inal digestion o f starch (Pc. 01) and duodenal starch flow (P c. 05) in ewes w as
influenced by diet. Effects of diet fed to ew es w ere found in duodenal CP flow
(P c. 0 5 ), d ietary escape p ro tein flow (Pc. 0 1) w ith d ietary escape p ro tein flow
g re a ter (P c. 01) in ew es fed com . M icrobial n itro g en co n cen tratio n in th e
duodenum w ere sim ilar in ew es fed each diet. M icrobial efficiencies differed
(P c. 05) in ew es fed th e various diets w ith values ran g in g fro m 13.3 to 2 1 .4 g
m icrobial p ro tein p ro d u c e d /1 0 0 g OM digested.
R esults from this stu d y
d em onstrate v ariatio n am ong lines o f b arley for in vitro DMDR and estim ated
m icrobial yield. These results also d em onstrate genotypic V ariation am ong b arley
cultivars site an d extent o f digestion.
I
CHAPTER I
INTRODUCTION
B arley is a w idely cultivated grain used for m alted beverages, h u m an an d
livestock feeds. In M ontana, barley is a n im p o rtan t com m odity. In 1987, M ontana
ranked second in th e n a tio n in th e p ro d u ctio n o f barley.
R eturns from b arley
account for eight p ercen t o f agricultural revenues (M ontana A gricultural Statistics,
1987).
As a feed grain, barley is com m only used for b o th ru m in an ts and n o n ­
rum inants. H ow ever, as a concentrate feed fo r rum inants, b arley has lim itations.
D igestive disorders such as rum inal acidosis and b lo at have b e en associated w ith
feeding high-concentrate barley diets to rum inants.
A lthough barley is a
concentrated energy source and contains m ore crude p ro te in th a n co m (NRC,
1984), c o m has rem ained th e preferred feed grain for cattle and sheep finishing
diets. Several reasons exist for this situation; digestive disorders are n o t as likely
to occur w h e n feeding corn-based concentrate diets and anim als receiving c o m are
believed to m ake m ore efficient use o f th e starch in the diet (W aldo, 1973).
Differences am ong barley cultivars have b een identified w ith respect to th e
n u tritio n al value o f cultivars for nonrum inants. Protein quality an d biological value
has b een show n to vary (H ofer et al, 1983; O verland, 1988) fo r nonrum inants.
Inform ation regarding cultivar differences as th ey p e rta in to ru m in an t usage
o f barley is lim ited.
Investigation o f b arley cultivars fo r ru m in an ts b eg an a t
2
M ontana S tate U niversity in 1985. Clark an d P etersen (1 9 8 7 ) found differences
am ong cultivars w ith respect to in vitro d ry m a tte r disappearance rates and
estim ated in vitro m icrobial yield. These m easures reflect functions w hich are o f
direct im portance to th e rum inant. If such differences are also p resen t in vivo, it
is possible th a t som e barley cultivars are m ore suitable th a n o th ers fo r ru m in an t
feed. Identification a n d /o r developm ent o f cultivars w hich m ay b e best utilized b y
sheep o r cattle m ay provide M ontana b arley producers a n expanded m arket fo r th e ir
product.
The objectives o f this study w ere:
1. To determ ine th e influence o f b arley genotype o n in vitro dry m a tte r
disappearance ra te an d estim ated m icrobial yield.
2. To determ ine th e relationship b etw een in vitro d ry m a tte r disappearance
ra te an d m icrobial yield to in vivo duodenal flow o f n u trien ts in m atu re ew es fed
barley diets differing in genotype.
3
CHAPTER 2
LITERATURE REVIEW
Bariev as a Feed G rain fo r R um inants
Feeding grain to rum inants is generally im plem ented w h e n production and
econom ic dem ands require rapid w eig h t gain. The starch in cereal grains provides
a co ncentrated source o f readily ferm entable su b strate fo r m icroorganism s in th e
rum en. C om is often th e grain of choice due to its hig h er concentrations o f starch
com pared to barley. Sorghum also has a h ig h er starch co n ten t th a n barley, w hile
w h e a t an d rye are usually com parable to th a t o f barley. W hile crude p ro tein o f
w h e a t m ay be greater, barley contains m ore crude p ro tein th a n com , oats and
sorghum . O f th e m ore com m on feed grains, oats contain th e h ig h est percentage o f
dry m a tte r as cm de fiber (12.2% ). Barley contains approxim ately 6% fiber w ith
com , w h eat, rye an d sorghum containing 2.5-3.2% , 2 .3 -2 .1%, 2.6% and 2.7%
respectively. In a study com paring th e feeding value o f sp ro u ted w h eat to sound
w h e a t an d barley, P reston et a l.(1 9 8 0 ) found n o differences due to grain type in
feedlot perform ance tra its (average daily gain, intake, fe e d /g ain ) o r in carcass
characteristics (dressing percentage, quality grade or yield g rad e).
M alcolm an d
Moss (19 8 4 ) found sim ilar production o f m ilk and b u tterfat in H olstein cows fed
com , barley o r 5 0 :5 0 com -barley diets.
4
C ultivar Effects o n Perform ance
Limited inform ation is available reg ard in g th e effect o f cultivars u p o n anim al
perform ance by rum inants. In a com parison o f m alting an d feed barleys, H inm an
(19 7 9 ) rep o rted im proved feed efficiency w h en feeding Klages, a m alting barley, vs.
Steptoe, a feed barley, th o u g h no difference in daily gain w as seen. N ew m an and
M cGuire (1985) suggested th e difference in feed efficiency m ig h t be a ttrib u ted to
th e h ig h er te st w eig h t o f th e Klages w hich suggests a h ig h er percentage o f starch
and therefore a g re a ter energy density. In a sim ilar study, P resto n and H erlugson
(1980) fed th e cultivars Boyer and Steptoe to yearling steers.
No a p p aren t
difference in perform ance w as seen w h e n barleys w ere rolled. H ow ever, w h e n fed
w hole, cattle fed Boyer gained 10 -1 2 % faster and m ore efficiently th a n th o se fed
Steptoe. The carcasses o f cattle fed Boyer w ere lean er th a n th o se fed Steptoe. The
barleys w ere sim ilar in n u trie n t com position, th o u g h S teptoe h a d slightly h ig h er
crude protein, crude fiber, acid d eterg en t fiber contents an d a slightly hig h er te st
w eight.
In a n o th e r study com paring th e A ndre, Steptoe and Klages cultivars in a steer
finishing trial found no differences b etw een cultivars for average daily gain. The
cultivar A ndre required p ro tein su pplem entation to m ain tain com parable feed
efficiency (M uirhead, 1987).
5
Physical and Chem ical C haracteristics o f Bariev
Physical C haracteristics.,
The physical form o f th e barley p la n t is highly variable w ith in and b etw een
varieties, how ever th e general m orphology o f th e kernel is sim ilar am ong genotypes.
Kernel shape ranges from elongated w ith tap ered ends to n e arly round. The o u te r
m ost layer o f th e kernel is th e husk, w hich m ay be ad h ered to th e kernel o r m ay
easily sep arate from it. Below th e husk lies th e pericarp layer an d th e testa, o r seed
coat. The pericarp, th e rem ains o f th e ovary w all, is fused to th e te sta to provide a
protective covering for th e tissues w ith in th e kernel. M ost o f th e fiber in th e b arley
g rain is found in th e husk, pericarp and te sta (Briggs, 1 9 7 8 ). The tissues found
w ith in th e te sta are th e starchy endosperm and kernel em bryo. The endosperm , th e
largest tissue w ith in th e testa, is th e storage place for th e en erg y reserves o f th e
grain as w ell as up to 80% o f th e to ta l p ro te in in th e grain (C hung and Pom eranz,
1985).
The o u te r layer o f th e endosperm is know n as th e aleu ro n e layer.
The
kernel em bryo lies to w ard th e base o f th e kernel.
Chem ical C haracteristics.
S tarch S tarch is th e m ajor chem ical com ponent o f th e barley grain. The
starch granules are laid dow n w ith in th e am yloplasts o f th e starch y endosperm as
th e seed m atures.
In th e central reg io n o f th e starchy endosperm , th e starch
granules are packed in to a protein m atrix. The starch granules ten d to be larg er
to w a rd th e cen ter o f th e endosperm an d decrease in size a n d q u an tity o f starch in
6
th e subaleurone region (Briggs, 1978).
granules.
The starch is deposited first in large
As th e kernel m atures, sm all granules are deposited (Karlsson e t al.,
1983). Sm all granules account for up to 90% o f th e n u m b er o f granules b u t only
ab o u t 10% o f th e starch w eight (Kang et al., 1985) .
Tw o m ajo r groups o f starches m ay be identified b ased u p o n th e X-ray
diffraction p a tte rn s cast by th e ir crystalline structures (French, 1973).
C ereal
starches are generally represented as A - type, w hile ro o t an d tu b e r starches are B type.
C hain len g th m ay be a facto r in determ ining starch type.
French and
Y oungquist (I9 6 0 ) determ ined th a t sh o rt chain am yloses crystallize in th e A form .
Longer chains ten d ed to p refer th e B form . Karlsson et al. (1 9 8 3 ) suggested th a t
variations in th e synthesis o f starch w ould resu lt in variations in th e final stru ctu re
o f th e starch and u p o n th e to ta l am o u n t o f carbohydrates produced. These factors
m ay cause v ariatio n in th e sw elling o f th e granules d u ring processing o r feeding
w hich does affect th e degradation activity o f enzymes.
The starch polysaccharide is composed of "
(straight chain,"
branched w ith "
-glucan and consists of amylose
(1-4) glucosidic linkages) and amylopectin ('
(I -4) chains are
(1-6) linkages) (Briggs, 1978). In barley, th e ratio of amylose to
am ylopectin is prim arily genetically determ ined (M orrison, e t al. 1986), th o u g h
minor variations m ay be a ttrib u ted to environm ental conditions du rin g early phases
o f th e developm ent o f th e grain.
7
Briggs (1978) states th a t m ost British barleys contain starch com prised o f 2226% am ylose an d 74-78% am ylopectin. Amylose co n ten t in b arley can vary from
0-50% .
O ver 90% o f th e starch in barley is ferm ented in th e rum en, as com pared to
84% o f th e starch in co m (W aldo, 1973). This extensive ferm en tatio n is believed
to be a facto r in th e digestive disorders associated w ith feeding h ig h co ncentrate
barley diets. S tarch w hich bypasses ru m en ferm en tatio n is hydrolyzed directly to
glucose in th e sm all intestine th ereb y avoiding energy losses th ro u g h ferm entation.
Because m ore co m starch th a n b arley starch bypasses th e ru m e n to th e sm all
intestine, W aldo (19 7 3 ) estim ated th e efficiency o f use o f m etabolizable energy to
be 47% fo r b arley an d 53% for co m (W aldo, 1973).
Fiber M ost o f th e fiber in barley is located in th e husk, pericarp and te sta
(Briggs, 1979). The husk consists o f thickened cell w alls w h ich co n tain m ost o f th e
lignin found in th e grain. In addition, cellulose, hem icellulose, pentosans, m an n an ,
uronic acids as w ell as substantial am o u n t o f silica m ake u p th e tissue o f th e husk.
In fully ripened grain, th e pericarp is dead tissue and th e te sta is constructed o f
"crude cellulose" (Briggs, 1978). A astm p e t al. (1984) identified th e testa as th e
location in barley of proanthocyanidins, a type o f phenolic com pound.
Bacic and Stone (19 8 1 ) evaluated th e chem ical com ponents o f th e aleurone
cell w all an d found it contained 44% xylose, 29% glucose, 23% arabinose, 2%
m annose and 2% galactose. Arabinoxylan and 1,3:1,4-$
-glucan constituted 60%
8
an d 20% o f th e polym ers in th e aleurone cell w alls. The susceptibility o f xylan to
acid hydrolysis is sim ilar to th a t o f starch (van Soest, 1 9 8 7 ). W ohlbier e t al. (1 9 6 9 )
as cited by Czerkaw ski (1986) indicated th a t th e digestibility o f xylan in th e ru m en
m ay reach 96% provided th e stru ctu re is accessible to ru m e n m icroorganism s.
Ballance and M anners (1978) evaluated th e com ponents o f th e cell w alls in th e
endosperm . T heir study indicated 70-72% o f th e carbohydrate polym er fraction
consisted of mixed linked $
-glucan. M ost o f the cell w all w as found to consist of
carbohydrate an d w as analyzed as 74% glucose, 13% D-xylose, 10% L-arabinose an d
2.5% D -m annose.
B eta-glucan
A class of soluble non-starch carbohydrate, $
-glucan, makes up
1.5 - 8.0% o f barley. Beta-glucan co n ten t varies am ong cultivars and is d ependent
u p o n genetic and environm ental grow ing conditions.
concluded th a t m ixed-linked I -3:1-4 $-glucans
T hom ke et al. (1 9 8 0 )
caused decreased g ro w th an d
interfered w ith digestibility of organic m atter, crude p ro tein an d energy in grow ing
pigs. H ow ever, o th e r studies have rep o rted digestion o f $-glucan
by sw ine
(W eltzien and A hem e, 1987; G raham et al.,1 9 8 6 b ). B eta-glucan is responsible fo r
restricting p ro tein and starch absorption in p o u ltry resulting in reduction o f in tak e
an d feed efficiency (H esselm an and @ m an, 1986).
rum inants and the viscous nature of $
The effects seen in n o n ­
-glucan has lead to th e postulation th a t this
soluble carbohydrate m ay be a causative facto r associated w ith b lo at in ru m in an ts
fed high-barley diets (E ngstrom and M athison, 19 88). A lthough $
-linkages are
9
readily attack ed b y ru m en m icroorganism s, $-glucans
m ay rem ain in tact lo n g
enough to increase th e viscosity o f th e ru m en fluid an d th e re b y lead to b lo at
problem s. H ow ever, E ngstrom and M athison (1 9 8 8 ) suggest th a t this m ay n o t be
the case. In their study using feedlot steers, $
-glucan levels ranging from 3.5% to
4 .8 % o f dry m a tte r appeared to have n o effect o n th e perform ance o f steers fed
high-concentrate barley diets. The authors suggested the range o f $
-glucan m ay
have b een to o n a rro w to d etect differences.
P ro tein The range in p ro tein co n ten t o f barley is m ore variable th a n o th e r
com ponents. P rotein co n ten t of barley is k n o w n to vary inversely w ith th e starch
co n ten t (Briggs, 1978).
Proteins found in barley as in o th e r cereals are: th e
album ins (w a te r soluble) and globulins (salt soluble), prolam ine (soluble in aqueous
alcohol) an d glutelins (soluble in acid o r alkaline solutions). T he w a ter an d salt
soluble proteins (album ins and globulins) m ake up 15 to 30% o f the to tal g rain
n itro g en (S hew ry et al., 1984).
These proteins are th e m ain com ponents o f th e
aleurone layer an d th e kernel em bryo, an d contain relatively h ig h levels o f lysine
an d th reonine. The prolam ines, know n in b arley as horde-in, are th e m ajor form o f
storage p ro tein in barley.
H ordein is considered a lo w quality p ro tein fo r
n o n ru m in an ts due to its low lysine content. The relative q u an tity o f ho rd ein to
album in a n d globulin is a determ ining facto r in barley p ro tein quality. G lutelins
also serve as storage proteins. Starch cells in b arley are su rro u n d ed b y a w all w hich
includes a p ro te in - possibly a glutelin (F oster and Prentice, 1 9 8 7 ). Ten to tw elve
i
10
p ercen t o f th e to ta l n itro g en in th e kernel is no n -p ro tein n itro g en (peptides, free
am ino acids, n itrates) (N ew m an and McGuire, 1985).
P rotein supplied to rum inan ts m ust m eet th e needs o f b o th th e rum inal
m icroorganism s and th e h o st anim al. Proteins en terin g th e ru m e n are subject to
hydrolysis to am ino acids by th e m icroorganism s.
The am ino acids are fu rth er
b roken dow n to am m onia, carbon dioxide and organic acids. A m m onia is th e chief
source o f n itro g en used by rum inal m icroorganism s for g ro w th an d reproduction.
M icroorganism s reorganize th e products o f proteolysis into different am ino acids and
peptides w hich m ay be incorporated in to m icrobial pro tein .
Thus, th e p ro tein
p resen ted to th e anim al in th e feed is n o t necessarily th e p ro te in presented to th e
sm all intestine. P rotein solubility (o r insolubility) is generally considered m ore
im p o rtan t th a n p ro tein quality w h en evaluating p ro tein for ru m in an t use (Church,
1 9 8 6 ).
Proteins w hich are m ore soluble m ay be expected to be m ore readily
available sources o f nitro g en for m icrobes in th e rum en (Van SoestjI 9 8 2 ). Proteins
w hich are m ore insoluble an d escape rum inal degradation (bypass protein) m ay be
expected to deliver m ore in tact d ietary p ro tein and am ino acids to th e sm all
intestine. Bypass protein, how ever, m ay n o t be satisfactorily digested in th e sm all
intestine. In addition, p artial rum inal d eg rad atio n o f p ro tein m ay result in a p o o r
balance o f am ino acids delivered to th e d u odenum (NRG, 1 9 8 4 ). M ahadevan e t al.
(19 8 0 ) concluded th a t solubility alone m ay n o t be a n in d icatio n o f th e degree o f
susceptibility o f proteins to proteases o f ru m en bacteria. S tru ctu ral characteristics
o f th e proteins are probably im portan t determ ining factors.
11
In a stu d y com paring sorghum , c o m an d barley, Spicer et al.(1 9 8 6 ) found
no differences in to ta l n itro g en in th e abom asum o f steers fed barley- and cornbased diets. H ow ever, partitio n in g th e nitrogenous com ponents show ed less barley
p ro tein escaping ru m en d egradatio n th a n c o m o r sorghum .
Phenolic com pounds
Plants co n tain a w ide a rra y o f phenolic a n d
polyphenolic com pounds. M any colors seen in flow ers, fruits an d vegetables m ay
be attrib u te d to th e phenolic com pounds in th e p lan t tissues. Phenolic com pounds
are derivatives o f th e arom atic am ino acids; tyrosine, phenylalanine an d try ptophan.
Barley contains a w ide num ber of phenolic substances.
T hese
com pounds are
found in num erous form s such as tyrosine, phenolic acids, esters, glycosides, lignans
an d re lated substances.
T he fo u r m ajor biochem ical classifications o f phenolic com pounds include
havonoids, terpenoids, benzoic acids and cinnam ic acids. T he flavonoid com pounds
are num erous, w idely distributed in plan ts an d often have physiologic activities in
additio n to lending color to plants (H arb o u m e e t al., 1975). Included in this group
o f com pounds are th e proanthocyanidins.
anthocyanidins
w hen
tre a ted
w ith
acid
Flavonoid com pounds w hich yield
are
proanthocyanidins (W einges and N ader, 1 9 8 2 ).
collectively
referred
to
as
In barley, th e aleurone an d th e
pericarp layers contain proanthocyanidins (A astm p et al., 19 8 4 ).
Phenolic
anthocyanidin pigm ents are responsible fo r th e red and blue colors seen in som e
barley tissues (Briggs, 1978) . R esearch b y th e brew ing in d u stry dem onstrated th a t
12
proanthocyanidins form com plexes w ith proteins in b eer creatin g a haze o f insoluble
precipitates (von W ettstein e t ah, 1980). D evelopm ent o f proanthocyanidin-free
m u ta n t barley varieties alleviated th e precip itatio n problem in b e er (von W ettstein
et al, 1980).
M unck (1981) suggested th a t sim ilar p recipitates m ay form in th e
digestive tra c t o f anim als th ereb y reducing p ro tein availability. In ra t and chick
trials, N ew m an et al. (1984) d em o n strated m ore highly digestible p ro tein in
proanthocyanidin-free m u ta n t cultivars com pared to n o rm al barley.
O verland
(1 9 8 8 ) dem onstrated num erically sm all th o u g h statistically significant differences
in p ro tein digestibility betw een proanthocyanidin-free m u ta n t cultivars and th e ir
norm al p a re n t barleys.
Phenolic com pounds are know n to have a n inhibitory effect o n a w ide v ariety
o f m icroorganism s in m any environm ents (Akin and Rigsby, 1985; T heodorou e t al.,
1 9 8 7 ). M icrobial g ro w th and cellulolytic activity o f ru m en m icroorganism s m ay be
inhibited by phenolic com pounds (Akin, 1982, Chesson, e t al.,1 9 8 2 ; Ju n g e t al.,
1983). N ordkvist et al.(1 9 8 4 ), evaluated eight abraded fractions o f barley grain fo r
analysis o f bound phenolic acids. Vanillic, p-coum aric, ferulic an d di-ferulic acids
w ere identified in all eight fractions isolated. Ju n g and Fahey, (1 9 8 3 ) dem onstrated
th a t vanillin is a n effective inhib ito r o f in vitro starch digestion by ru m en
m icroorganism s.
Phenolic com pounds are also know n to in te ra ct w ith proteins
reducing th e ir n u tritio n al value for anim als. Sorghum cultivars w ith high levels of
tan n in s have poorly digestible p ro tein com pared to cultivars w ith low levels
(Cousins e t al., 1981).
13
CHAPTER 3
MATERIALS AND METHODS
In Vitro E valuation
From th e barleys evaluated b y Clark an d P etersen (1 9 8 7 ), eight cultivars
w ere selected for reevaluation. The selection o f these barleys w as based u p o n in
vitro dry m a tte r disappearance ra te (DMDR) and pu rin e accum ulation. The Cultivars
selected included Cl 15478, a norm al barley; ANT 534, ANT 563, ANT 230, ANT
231, ANT 246, proanthocyanidin-free m u ta n t cultivars; CA 6 0 2 9 1 4 ,
57163, cross-line barleys.
an d
CA
The barleys w ere analyzed fo r crude p ro tein co n ten t
(AOAC,1980), n e u tra l d etergent fiber (NDF) fraction (Van Soest an d R obertson,
1980), starch co n ten t (@ m an and H esselm an, 1984), to ta l flavonoid co n ten t
(Truelson, 1984), total polyphenol content (Folin and Denis, 1912), and total $
glucan co n ten t (M cCleary e t al.,19 8 5 )(Table I ) .
Lim itations of lab o rato ry space and equipm ent precluded sim ultaneous
analysis o f th e cultivars. M ultiple runs w ere conducted evaluating four cultivars in
each ru n . Cultivars w ere assigned to runs such th a t each cultivar w as included in
a t least th re e runs. A ppendix Table 14 illustrates th e a rran g em en t o f cultivars an d
ferm en tatio n runs. The inclusion o f cultivars in m ultiple ru n s allow ed com parisons
across runs.
14
TABLE I . CHEMICAL COMPONENTS OF NORMAL, PROANTHOCYANIDINFREE AND CROSS-LINE BARLEYS
Barley
Starch
%
Cl 15478
ANT 53 4
AN5 536
ANT 230
ANT 231
ANT 246
CA 6 0 2 9 1 4
CA 57163
53.4
49.1
4 8 .9
52.9
4 9 .6
52.3
52.2
54.5
P rotein
%
12.9
13.0
11.0
11.9
13.9
13.1
12.2
12.0
NDFa
%
12.3
15.5
14.6
12.8
11.8
13.9
13.4
14.6
$-glucanb
%
4.51
4.9 9
4 .9 7
5 .04
4.22
3.85
4 .7 4
4.7 9
FlavonoidscPhenolsd
m g /g
m g /g
0.7 8
0 .2 9
0.0 2
0.01
0 .1 6
0.1 2
0.0 2
0.0 2
3.5 8
1.92
1.51
1.41
1.64
1.65
1.34
1.35
aN eutral D etergent Fiber
bT otal $-glucan
cT otal Havonoids com pounds
dT otal polyphenolic com pounds
The barleys w ere evaluated fo r DMDR using a m odified Tilley and T erry in
vitro ferm en tatio n procedure as described b y H arris (1 9 7 0 ). Barleys w ere g round
in a Udy m ill to pass a I m m screen. H alf gram sam ples w ere soaked w ith 3 0 m l
M cDougal’s buffer (M cDougal, 1948), inoculated w ith 7 m l o f rum inal fluid, an d
th en incubated a t 39A
C in tubes capped w ith Bunsen valves. The rum inal inoculum
w as a com posite o f fluid collected from tw o rum inally can n u lated cows fed 4.5 kg
barley daily. F erm entation w as ceased after 0, 3, 6, 9, 12, 15, 18, 21, 24, 36, an d
48 ho u rs o f incubation using .5 m l 5% m ercuric chloride solution.
Three tu b es
containing sam ples o f each cultivar w ere tre a te d a t each tim e interval. The en tire
contents o f each tu b e w as dried a t 60AC
in a forced a ir oven for 4 8 hours.
15
D isappearance rates for dry m a tte r w ere determ ined usin g th e equation:
DM residue rem aining = D e ('kd)® + U
w here D = th e p o tentially degradable fraction, -kd = ra te co n stan t fo r DM
disappearance, t = tim e (hrs) and U = undegradable fractio n (R obinson e t al.,
1986).
D ried residues w ere analyzed fo r pu rin e co n ten t u sin g th e technique
described by Zinn an d O w ens (1 98 6 ). A curve rep resen tin g p u rin e co ncentration
over tim e w as developed an d th e area u n d e r th e curve w as utilized to estim ate
m icrobial yield as described by B urden et al. (19 7 8 ).
R elationships betw een chem ical com ponents an d d ry m a tte r disappearance
ra te an d pu rin e accum ulation w ere characterized b y sim ple regression techniques
using th e C orrelation Procedures o f th e G eneral Linear M odel o f th e Statistical
Analysis System (SAS), (1 984).
M etabolism Study
From th e eight barleys evaluated in th e in vitro procedure, four w ere chosen
for in vivo evaluation. The cultivars chosen included th e n o rm al barley Klages, th e
proanthocyanidin-free m u ta n t cultivars Advance ANT 534, G unhild ANT 246, an d
T ron ANT 231. B arley fed in th e in vivo stu d y w as grow n u n d e r irrigation th re e
m iles w est o f Bozem an, MT by W estern Plant Breeders A ssociation. These barleys
w ere characterized using th e in vitro procedure described above.
16
E xperim ental diets w ere form ulated using th e fo u r selected barleys (Table 2).
A fifth diet w as form ulated using c o m as th e p rim ary ingredient.
Diets w ere
form ulated to supply equal am ounts o f starch (350 g /d ), crude p ro tein (170 g /d )
an d NDF (235 g /d ).
D iets w ere fed to five m atu re (3 and 4 yrs) R am bouillet ew es fitted w ith
rum inal a n d duodenal cannulae (Aquilar an d D epeters, 1 9 8 8 ). Animals w ere fed
tw ice daily a t 6 a.m . and 6 p.m . and w ere dosed a t feeding w ith 2.5 g Cr2O3 w hich
w as used as a n external digesta m arker.
Diets w ere random ly assigned to ew es
during five periods in a 5 X 5 Latin square arran g em en t o f treatm en ts.
Periods
consisted o f tw o w eeks for diet ad ap tatio n an d one w eek follow ing ad ap tatio n fo r
sam ple collections.
A pproxim ately 2 5 0 m l digesta w ere collected from th e du o d en u m 0, 3, 6, and
9 h p o st feeding. T en m l sam ples w ere im m ediately w eighed an d dried for analysis
o f dry m a tte r and ash contents (AOAC, 19 8 0 ).
A 50 m l sam ple o f digesta w as
acidified w ith 3 m l o f 6 N HCl and frozen fo r am m onia analysis by m agnesium
oxide distillation (AOAC, 1980). The rem aining digesta w as fro zen u p o n collection
an d subsequently freeze-dried. The freeze-dried sam ples w e re finely ground in a
B raun h a n d held coffee/spice mill (2 m in). Q uarter gram sam ples o f dry digesta
w ere analyzed for chrom ic oxide (F enton an d Fenton, 19 7 9 ) fo r d eterm ination o f
duodenal digesta flow. Crude p ro tein w as determ ined usin g Kjeldahl procedures
(AOAC, 1980) and starch conten t w as determ ined according to @ m an an d
H esselm an (1 984).
17
O ne d ay follow ing th e duodenal sam pling, rum inal digesta w as collected a t
0, I , 2, 3, 4, 5, 6, 7, 8.5, 10 and 12 h post-feeding. R um inal pH w as m easured
im m ediately u p o n collection using a com bination glass electrode pH m eter. R um inal
fluid w as extracted by squeezing digesta th ro u g h 4 layers o f cheese cloth. Fifty m l
o f rum inal fluid w ere acidified w ith 3 m l o f 6 N Hcl and fro zen fo r la te r analysis o f
am m onia using th e m agnesium oxide distillation procedure (AOAC, 1980). T w enty
m l rum inal fluid w ere frozen and la te r com posited for viscosity m easurem ents using
a H aake falling ball viscom eter set a t 30AC.
In ord er to have adequate fluid to fill
th e viscom eter, sam ples collected d u ring th e first 6 collections w ere com posited fo r
viscosity m easurem ents as w ere sam ples from th e last 5 collections.
Pellets
containing m icrobial cells harvested from experim ental ew es w ere utilized fo r
determ in atio n o f nitrogenrpurine ratio as described b y Sm ith an d McAllan (1 9 7 4 ).
This ratio serves to allow calculation o f m icrobial nitro g en flow in th e duodenum .
Tw o days follow ing rum inal collections, in situ dry m a tte r disappearance w as
evaluated using polyester bags w ith a surface area o f 5 0 cm2 and pore size o f
53'
IOjLt (Nocek, 1988). Twenty-eight bags containing I g of grain (ground to pass
a 2 m m screen) representative o f th e diet received by each ew e w ere suspended in
th e ru m e n o f th e anim al. Two ew es received a n additional 1 4 em pty bags to be
used as blanks. Two bags containing grain w ere rem oved from each ewe a t each
collection. At each collection one b lan k b ag w as rem oved from each o f th e tw o
ew es w ith blanks.
Bags w ere tre a ted w ith 5 m l 5% HgCl2 an d rinsed in cold w a te r
u n til th e w a te r ra n clear.
Bags w ere dried a t 60C for 4 8 h an d Weighed.
Dry
18
m a tte r disappearance w as determ ined by w eig h t difference. W eight changes in th e
blank bags w ere utilized as correction values w hich account fo r th e influx o f
rum inal debris into grain-filled bags rem oved a t th e sam e tim e intervals. C ollection
tim es w ere .75, 1.5, 2.25, 3.0, 3.75, 4.5, 5.25, 6.0, 7.5, 8.25, 9.0, 10.5, 12 an d 2 4
hours p o st feeding. The 6 p.m . feeding w as elim inated in o rd e r to m ain tain
u n in te rru p ted incubation conditions.
Statistical Analysis
In V itro.
D ata from th e in vitro study w ere analyzed using analysis o f variance. W here
a significant F-statistic w as detected, m eans w ere com pared using th e Least
Significant difference m ethod on th e G eneral Linear M odel pro ced u re of Statistical
Analysis Systems (SA S ),(1986). The m ain effects in th e statistical m odel w ere b arley
an d run.
Linear regression using th e procedures o f SAS (1 9 8 6 ) w as used to
gen erate co rrelation coefficients for th e chem ical com ponents o f barley and DMDR
an d pu rin e accum ulation.
M etabolism Study.
Analysis o f th e d a ta from th e m etabolism study w as conducted Using analysis
o f variance procedures on th e G eneral Linear M odel o f SAS. T he m ain effects in th e
m odel w ere period, ew e an d treatm en t. Least Squares M eans w e re com pared w h ere
significant F-statistics w ere found using th e Least Significant Difference m ean test.
C orrelation coefficients betw een in vitro DMDR an d rum inal starch digestibility an d
b etw een in vitro pu rin e accum ulation an d duodenal m icrobial nitro g en w ere
g en erated by lin ear regression using th e procedures o f SAS (1 9 8 6 ).
20
CHAPTER 4
RESULTS AND DISCUSSION
In Vitro Study
The DMDR an d purine yield differed ( P c .05) am ong b arley cultivars (Table
2.)
D isappearance rates ranged from 8 .4 7 % /h r (ANT 2 3 0 ) to 1 0 .1 4 % /h r (ANT
2 3 1 ). Purine yield in 4 8 hours ranged from 7.60 m g (Cl 1 5 4 7 8 ) to 8.72 m g (ANT
2 46) w hich w ere different ( P c .05).
TABLE 2. THE INFLUENCE OF BARLEY CULTIVAR ON DRY MATTER
DISAPPEARANCE RATE (DMDR) AND PURINE YIELD
IN BARLEY DURING IN VITRO FERMENTATION.
Item
ANT 231
CA 6 0 2 9 1 4
ANT 563
CA 57163
ANT 246
Cl 15478
ANT 53 4
ANT 230
DMDR
(% /H r)
10.14b
9 .2 5 ab
9 .2 3 ab
8 .8 a
8 .6 7 a
8 .6 6 a
8 .5 5 a
8 .4 7 a
S.E.
0.41
0.42
0.42
0.41
0.41
0.33
0 .46
0.41
Purine
(m g)
8 .0 0 abc
7.6 2 bc
7.9 1 abc
/ . S l bc
8 .7 2 ad
7 .6 0 ^
8 .5 3 acd
8 .0 9 abc
M eans in colum ns w ith different superscripts differ, ( P c . 0 5 ).
S.E.
0.22
0 .28
0.23
0.2 2
0.21
0.1 7
0 .2 4
0.22
21
The co rrelation betw een DMDR and pu rin e yield, NDF o r CP c o n ten t o f barley w as
n o t significant (P > .1 ) (Table 3.) A positive association w as seen b etw een CP and
NDF an d p urine accum ulation.
W hile th e CP effect m ig h t be expected, th e
correlation (r= .4 6 ) betw een NDF and p u rin e w as unexpected. This correlation m ay
be due to th e cation-exchange capacity o f th e fiber m atrix.
C ation exchange
capacity is a n im p o rtan t factor in m icrobial attach m en t (Allen e t al., 1985) an d can
be used as a m easure of th e binding ability o f th e fiber m atrix (M cBum ey et
al.,1 9 8 6 ).
The association betw een DMDR an d pu rin e yield m ay be described as
quadratic (r= .8 9 ).
As m ight be expected, purine yield initially increased With
increasing DMDR. As DMDR continued to accelerate how ever, pu rin e yield peaked
an d b eg an to decline. The results indicate less purine yield fo r several o f th e m ost
rapidly ferm enting cultivars and g reatest accum ulation fo r barleys w ith m ore
m o d erate DMDR.
The cultivar w ith th e h ighest DMDR (ANT 2 3 1 ) show ed less
purine yield th a n th e cultivar w ith th e low est DMDR.
This relationship is
ap p aren tly c o n trary to th e long standing assum ption th a t increased ferm en tatio n
leads to increased m icrobial yield (nrskov, 1971; W aldo, 1 9 7 3 ).
The response
rep o rted in this study is supported by th e w o rk o f Hespell an d B ryant (1979) w h o
rep o rted decreased m icrobial yield in a rum inal environm ent characterized b y
adequate levels o f readily available energy b u t lim iting concentrations o f free
nitrogen.
TABLE 3. CORRELATIONS (r) OF CHEMICAL CONSTITUENTS OF BARLEY WITH IN VITRO
DRY MATTER DISAPPEARANCE RATE AND PURINE ACCUMULATION
Rate
Purine
1.0
0.0
0.03
0.77
Flava
Phenolb
/9-Glu
-0.44
<0.01
-0.30
0.01
-0.31
<0.01
-0.02
0.83
0.46
< 0.01
-0.38
<0.01
-0.32
< 0.01
-0.37
<0.01
-0.29
0.01
-0.42
<0.01
-0.08
0.49
0.38
<0.01
0.29
0.01
-0.67
< 0 .0 1
-0.28
0.01
-0.41
<0.01
-0.43
<0.01
0.41
< 0 .0 1
0.23
0.04
0.27
0.02
-0.13
0.26
0.99
<0.01
-0.20
0.07
Protein
NDF
0.06
0.62
-0.07
0.53
0.3 0
< 0 .0 1
Starch
Rate
r
P
Purine
r
P
Protein
r
P
NDF
r
P
Starch
r
P
Flava
r
P
Phenolb
r
P
aT otal flavonoid com pounds
bTotal polyphenolic com pounds
-0.19
0.10
23
An unexpected negative association w as seen b etw een starch and DMDR
(P < .0 1 ).
This surprising resu lt m ay be explained by th e positive correlation o f
polyphenolic com pounds w ith starch (r= .2 7 ).
Flavonoid an d to ta l polyphenolic
contents w ere negatively associated w ith DMDR ( P c .0 1 ). In v itro studies by Ju n g
an d F ahey (1983) dem onstrated a lin ear decrease in cellulose an d starch digestion
w ith increasing levels o f phenolic com pounds. Thus, w hile th e expected response
to a n increase in starch concentration w o u ld be m ore rapid DMDR, th e correspond­
ing increase in phenolic com pound levels m ay inhibit m icrobial function th ereb y
reducing DMDR. Flavonoid com pounds w ere also found to be negatively associated
w ith p urine accum ulation (r= -.3 2 ).
This correlation m ay be a n indication o f
restrictio n o f free n itro g en by flavonoids. This contentibn is su p p o rted by M unck
(1981) w ho suggested th a t proteins m ay be precipitated in th e digestive tra c t by
proanthocyanidins.
The negative correlation betw een co n ten t o f polyphenolic
com pounds an d purine accum ulation (r= -.3 7 ) m ay indicate restricted activity o f
ru m en m icroorganism s as suggested b y T heodorou et al. (1 9 8 7 ) and Ju n g an d
Fahey (1 9 8 3 ). T hough no association (P > . I ) w as seen b etw een DMDR and $
glucan content, $-glucan
p urine yield (r= -.2 9 ).
did dem onstrate a negative association ( P c .05) w ith
This resu lt m ay be a n indication o f inhibition o f th e
atta ch m e n t o f m icroorganism s. A ttachm ent inhibition o f this ty p e has been rep o rted
in th e presence o f m ethylcellulose, a soluble carbohydrate (Kudo, e t al., 1986).
The results o f this study dem onstrate th a t rates o f in vitro DMDR an d
estim ated m icrobial yield can be a ttrib u ted to genotype.
In addition, chem ical
24
constituents o f barley w ere show n to influence DMDR and estim ated m icrobial yield
an d m ay serve as predictive tools to assess th e feeding value o f various barleys.
M etabolism Study
The barleys used in th e in vitro stu d y (harvested in 19 8 6 ) ranked in o rd er o f
increasing rate: Advance ANT 53 4 < Klages < G unhild ANT 2 4 6 < T ron ANT 231
w ith DMDR o f 8.55, 8.66, 8.67 and 1 0 .1 4 % /h , respectively. Barleys harvested in
1988 for use in th e m etabolism trial ran k ed Advance ANT 5 3 4 < G unhild ANT 2 4 6
< T ron ANT 231 < Klages w ith DMDR values o f 5.69 < 6 .8 8 < 7.42 < 8.52 % /h ,
respectively. The proanthocyanidin-free m u ta n t cultivars did n o t change ran k in g
relative to one another. H ow ever, th e n orm al barley Klages ran k ed as th e fastest
ferm enting barley in th e second evaluation w as th e th ird fastest ferm enting b arley
in th e first experim ent.
V ariation b etw een in vitro runs is to be expected, in
p a rticu lar w h e n evaluating cultivars from different p roduction years. Therefore, th e
change in ranking rep o rted here should n o t be considered a discredit to th e
experim ent. It is im p o rtan t to n ote th a t only one cultivar changed rank.
The com position o f th e tre atm en t diets is listed in Table 4.
The chem ical
analysis o f th e diets is listed in Table 5. By design, dry m a tte r an d organic m a tte r
in take w ere th e sam e am ong ew es fed each diet (Table 6). Flow o f DM to th e sm all
in testine w as different ( P c .05) (Table 7). R ate o f DM flow ran g ed from 3 5 7 .4 g /d
for th e T ron ANT 231 diet to 4 42.0 g /d fo r th e co m diet. O rganic m a tte r flow to
25
th e duodenum also differed (P c .O l) w ith values ran g in g from 3 4 3 .5 g /d (T ron ANT
2 31) to 4 3 8 .5 g /d (com ).
TABLE 4. COMPOSITION OF TREATMENT DIETS (% AS FED)
D iets3
Ingredients
KLA
Barley
C om
Beet Pulp
U rea
Dical Phosb
TMSc
V itam in A,D,Ed
ADV
GUN
TRON
60.5
67.9
62.1
6 4 .6
-
-
-
-
36.5
1.8
.8
.2
.1
29.0
1.9
1.1
.2
.1
34.9
1.8
.9
.2
.1
32 .9
1.2
1.0
.2
.1
CORN
-
63.5
33 .7
1.6
.6
.2
.1
a KLA = Klages, ADV = Advance ANT 534, GUN = G unhild ANT 246
TRON = T ron ANT 231
b dicalcium p hosphate
c TMS = Trace M ineralized Salt
d V itam in A an d D prem ix containing 2 0 ,0 0 0 ,0 0 0 IU Vit.A an d
4 ,0 0 0 ,0 0 0 IU Vit. D. p e r pound o f prem ix.
TABLE 5. CRUDE PROTEIN (CP), STARCH AND NEUTRAL DETERGENT
FIBER (NDF) CONTENT OF TREATMENT DIETS (%)
D iets3
Item
KLA
ADV
GUN
TRON
CORN
CP
STARCH
NDF
16.4
33.0
30.6
16.5
33.5
31.3
14.4
29 .7
29 .8
15.5
42.3
35.1
13.5
30 .2
2 3 .8
a KLA = Klages, ADV = Advance ANT 534, GUN = G unhild ANT 246
TRON = T ron ANT 231
26
TABLE 6. DAILY INTAKE (G) OF DRY MATTER (DM), ORGANIC MATTER (OM),
STARCH, CRUDE PROTEIN (CP) AND NEUTRAL DETERGENT FIBER (NDF)
D iets3
Item
KLA
DM
1010.0
OM
1008.0
CP
174.8
STARCH 3 51.0
NDF
3 2 6 .4
ADV
995.0
9 94.0
171.6
3 49.0
325.8
GUN
1010.0
1008.0
151.2
3 1 3 .0
3 1 3 .0
TRON
1022.0
1020.0
171.7
3 8 4 .0
4 4 6 .6
CORN
1207.0
1197.0
165.2
450.0
253.5
a KLA = Klages, ADV = Advance ANT 534, GUN = G unhild ANT 246
TRON = T ron ANT 231
TABLE 7. INFLUENCE OF TREATMENT DIET ON PERCENT RUMINAL
DIGESTION AND DUODENAL FLOW OF DRY MATTER (DM)
AND ORGANIC MATTER (OM)
Item 3
DM
D igestion
DM
Flow
OM
D igestion
OM
Flow
KLA
ADV
GUN
TRON
CORN
S.E.
6 2 .3 ab
5 7 .7 a
5 8 .Oab
69.2b
5 6 .2 a
2.45
3 8 0 .6ab
4 2 6 .4 ab
4 2 4 .4 ab
357.4*
4 4 2 .Ob
24.3
6 2 .7 ab
5 7 .6 a
58 .4 ab
6 3 .5 ab
6 5 .3b
2.17
3 7 1 .8a
4 2 1 .5b
4 2 1 .2b
3 4 3 .5a
438.5b
16.3
a KLA = Klages, ADV = Advance ANT 534, GUN = G unhild ANT 246
TRON = T ron ANT 231
M eans in row s w ith different superscripts differ, P < .0 5 .
The p ercentage o f DM digested in th e ru m e n expressed as a percentage o f DM fed
ran g ed from 56.2% for co m to 69.2 % fo r T ron ANT 231 (T able 7). H ynd an d
A lden (1985) rep o rted 75-83% DM digestibility o f b arley fed to sheep. R um en
27
digestible OM differed ( P c .05) w ith values ranging from 57.6% in ew es fed
A dvance ANT 5 3 4 to 65.3% in ewes fed com . These values are sim ilar to th o se o f
M organ e t al. (1 9 8 9 ), w ho rep o rted OM digestibility o f 69% fo r a h ig h concentrate
barley diet and 66% for a sim ilar co m diet.
B loat an d rum inal acidosis are digestive disorders o ften associated w ith
feeding high-concentrate barley diets.
no effect (P > .1 ) on rum inal pH.
In this study, b arley genotype o r co m h ad
R um inal pH in ew es ran g ed from 5.6 to 5.8.
H ynd an d Alden (19 8 5 ) rep o rted a m ean pH o f 5.6 in sheep fed h ig h barley diets
w ith no ap p aren t sym ptom s o f acidosis. Thick, viscous ru m in al contents traps gases
produced during ferm entation. If th e anim al is unable to expel these gases, b lo at
m ay result.
W hile no differences w ere seen in rum inal fluid viscosity across
treatm en ts, viscosity appeared to be inversely related to $
-glucan content o f th e
grain. A lthough bloat in anim als fed concentrates is m ore com m only associated
w ith barley, it is in teresting to n o te th a t rum inal fluid viscosity w as g reatest in
anim als fed th e c o m diet. Viscosities, expressed in centipoise u n its (cp) ranged from
2 .8 cp (Advance ANT 534) to 5.1 cp (co m ) (Table 8). E ngstrom and M athison
(1988) found no negative effects on perform ance of feedlot steers due to $
-glucan
in b arley based finishing diets. The sam e stu d y estim ated th e rum inal digestibility
o f $-glucan
to be approxim ately 98.1% .
Interesting results w ere derived from th e in situ digestibility m easurem ents
(Table 9 ). No differences am ong b arley cultivars w ere seen an d all barleys w ere
m ore extensively digested ( P c .01) in 2 4 h o u rs th a n com . D igestion values fo r all
28
grains w ere w ell below accepted values (nrskov, 1986; W aldo, 1973) o f over 90%
for barley an d 82-86% for com . Values fo r th e barley cultivars ran g ed from 48 .3
to 59.9 % w hich w ere different ( P c . 05) th a n co m (9.8% ).
TABLE 8. INFLUENCE OF TREATMENT DIET ON RUMINAL FLUID
VISCOSITY AND TOTAL BETA-GLUCAN CONTENT
D iets3
$-glucan
to ta l %
KLA
ADV
GUN
TRON
CORN
4.26
4.63
3.45
4.12
.13
Viscosity
(cpb)
3.9
2.8
4.5
4.2
5.1
S.E.1
.77
.77
.77
.77
.77
a KLA = Klages, ADV = Advance ANT 534, GUN = G unhild ANT 246
TRON = T ron ANT 231
b centipoise units
c S tandard e rro r o f th e m ean viscosities
Barleys ranked differently th a n w h e n evaluated for DMDR. W hile th e T ron
ANT 231 h a d a significantly higher IVDMDR th a n th e o th e r cultivars, no difference
in in situ DMDR w as found. The Advance ANT 246 ap p eared to have th e m o st
rap id in situ DMDR relative to th e o th e r cultivars, y et h a d one o f the slow est
IVDMDR values.
T he in situ digestibility values are questionable due to th e extrem ely low
values. It is possible th a t th e thick, viscous n a tu re o f th e m m in a l fluid in terfered
w ith norm al ferm entation o f grain sam ples inside th e bags.
Odle and Schaefer
(1987) suggested th e viscous m m in al fluid o f co ncentrate fed anim als ten d ed to
29
plug th e pores in nylon bags preventing th e escape o f gases. B allooning o f th e bags
w as seen in this study in all periods and all treatm en ts, w hich m ade rinsing th e bags
difficult. Since this problem did n o t ap p ear to differ b etw een diet treatm en ts, th e
low digestibility o f co m cannot solely be explained b y th ese observations. T hough
this technique has been considered useful in determ ining digestibility o f concentrate
feeds, it is ap p aren tly n o t adequate w h e n attem p tin g to describe a ra te o f
disappearance.
TABLE 9. EFFECT OF DIET ON IN SITU DIGESTIBILITY
OF BARLEY CULTIVARS AND CORN
Item 3
% digestibility
KLA
ADV
GUN
TRON
CORN
SEb
59 .9 C
63.9=
48.3=
57.3=
9 .8 d
7.24
a KLA = M ages, ADV = Advance ANT 534, GUN = G unhild ANT 246
TRON = T ron ANT 231
b Pooled stan d ard erro r o f th e m ean.
M eans in colum n w ith different superscripts differ ( P c .01)
The ran k in g o f rum inal digestibility o f starch resem bles IVDMD to a m uch
g re a ter ex ten t th a n th e in situ digestion. Ewes fed th e c o m d iet h a d rum inal starch
digestibility o f 82.3% w hich w as low er ( P c . 01) th a n th e digestibilities o f all barley
cultivars except G unhild ANT 246 (87.0% ) (Table 10). These results agree w ith
Spicer e t al (1986) w ho reported b arley starch to be slightly m ore ru m en
degradable th a n co m starch w h en fed to steers. M organ e t al. (1 9 8 9 ) rep o rted 95-
30
97% rum inal starch digestion for barley and 92-97% digestibility fo r co m starch in
ew es fed w hole grain. W hile th e ran k in g o f barley cultivars w ith reg ard to rum inal
starch digestion w as n o t identical to th e IVDMDR ranking, th e m ost rapidly
ferm enting cultivars, Klages and T ron ANT 231 w ere also th e cultivars w ith th e
m ost highly ru m en digestible starch. Likewise, th e tw o cultivars w ith the slow est
IVDMDR, A dvance ANT 53 4 and G unhild ANT 246, w ere th e tw o w ith less ru m e n
digestible starch.
S tarch w hich bypasses th e ru m en is hydrolyzed directly to glucose in th e
sm all intestine. S tarch utilized in th e sm all intestine is used m ore efficiently th a n
starch ferm ented in th e ru m en as ferm en tatio n to volatile fa tty acids results in th e
p ro d u ctio n of h e a t an d gases (W aldo, 1 9 7 3 ). This rep resen ts energy lost to th e
anim al.
TABLE 10. EFFECTS OF TREATMENT DIET ON RUMINAL STARCH
DIGESTION AND STARCH FLOW TO THE DUODENUM
Item 3
KLA
ADV
GUN
TRON
CORN
S.E.b
R um inal
digestion
(%)
9 2 .9 de
8 9 .3 de
8 7 .Ocd
93,8=
82.3=
0.73
D uodenal
flow
(g /d )
D uodenal flow as
as % o f intake
(% )
5 .9 d
7.6cd
9 .5 d
8 .I d
14.6=
0.7 0
1.7
2.2
3 .0
1.8
3 .8
a KLA = Klages, ADV = Advance ANT 534, GUN = G unhild ANT 246
TRON = T ron ANT 231
b Pooled stan d ard erro r
M eans in colum ns w ith different superscripts differ, P < .05.
31
W hile th e low er rum inal digestibility fo r c o m starch w as expected, this stu d y
dem onstrates th a t barley genotype m ay influence th e q u an tity o f starch delivered
to th e sm all in testine and therefore influence th e efficiency w ith w hich b arley
energy is used for g ro w th by rum inants. The flow o f starch to th e duodenum w as
g re a ter ( P c .05) in ew es fed com . The h ig h er q u an tity o f starch (1 4 .6 g /d ) in th e
duodenum o f ew es fed co m w as expected (T able 10).
In ew es fed Klages (th e
norm al barley) 5.9 g o f starch flow ed to th e duodenum p e r d ay w hich w as less
( P c .05) th a n th a t in ew es fed th e p roanthocyanidin-free m u tan ts G unhild ANT 2 46
(9.5 g /d ) and T ron A nt 231 (8.1 g /d ) and Advance ANT 5 3 4 (7.6 g /d ).
It is
p articularly in teresting to n o te th a t th e G unhild ANT 246 d iet provided from 36-71
g /d less starch th a n th e o th e r barley diets, how ever th e du o d en al starch flow w as
num erically g reater for th e G uhhild ANT 2 4 6 diet th a n fo r all o th e r barley diets
(Table 10). This m ay be a n indication o f som e degree o f resistance to bacterial
enzym e activity as rum inal starch digestibility o f G unhild ANT 2 4 6 w as th e least
am ong th e barley diets.
D uodenal starch contents expressed as a percentage o f
starch fed fu rth er defines th e num erical ran g e o f duodenal starch flow due to diets.
V alues ran g ed from 1.7% to 3.0% starch fed am ong barley treatm en ts. M organ e t
a l.(1 9 8 9 ) rep o rted 3-5% intestinal digestion o f starch from sim ilar w hole g rain
barley based diets.
In a com prehensive review of starch utilization by ru m in an ts, T heurer (1 9 8 6 )
n o te d th a t digestibility o f p ro tein and starch in cereal grains are related.
Since
starch granules are em bedded to varying degrees in a p ro tein m atrix, the stru ctu re
32
o f th e m atrix an d th e digestibility o f th e p ro tein can affect access o f th e rum inal
m icroorganism s to th e starch granules. Both starch and p ro tein o f barley are m ore
digestible th a n those o f co m (Spicer e t al.,1 9 8 1 ).
Differences in th e starch
com position o f th e cultivars used in this stu d y m ay tran slate to differences in th e
susceptibility o r resistance to ru m en degradation.
R um inal NH3 concentration w as sim ilar for ew es fed th e barley cultivars
(Table 11). R um inal NH3 concentrations ran g ed from 2 8.2 m g /1 0 0 m l in ew es fed
Klages to 3 7 .8 m g /1 0 0 m l for co m fed ew es (P > .1 ). These results do n o t agree
w ith Odle an d Schaefer (19 8 7 ) w ho found rum inal NH3 concentrations to be g re a ter
for barley th a n for com .
R um inal NH3 values for b arley diets in this stu d y
correspond to those o f H ynd and Alden (1 9 8 5 ) w ho rep o rted a ran g e of 24.5 to
6 3 .4 m g /1 0 0 m l o f rum inal fluid in b arley fed sheep.
TABLE 11. EFFECTS OF TREATMENT DIETS ON RUMINAL AND
DUODENAL AMMONIA (NH3) CONCENTRATION (M G /100M L)
D iets3
M easurem ents
R um inal NH3
D uodenal NH3
KLA
28.2
6.5
ADV
GUN
TRON
CORN
S.E.
35.0
7.3
33.7
8.0
33.4
6.7
3 7 .8
6.8
4 .8
0.6
a KLA = Klages, ADV = Advance ANT 534, GUN = G unhild ANT 246
TRON = T ron ANT 231
A m m onia is a pro d u ct o f pro tein deg rad atio n in th e ru m en an d differences in NH3
concentrations m ay be a n indication o f differences in th e digestibility o f the p ro tein
in th e feed.
Differences in th e rum inal levels o f NH3 m ay also be indicative o f
33
differences in NH3 use by m icroorganism s in th e rum en. It is im p o rtan t to n o te th a t
each o f th e diets contains a sm all percentage o f u rea an d th a t th e am ounts differ
slightly, com plicating th e in te rp re ta tio n o f rum inal NH3 analysis d ata. The ran g e
o f ru m e n NH3 resulting from feeding th e barley diets, th o u g h n o t statistically
significant, is in terestin g because o f th e distribution.
The in vitro phase o f this
project suggested negative influences o f phenolic com pounds o n m icrobial yield.
Ewes fed diets form ulated w ith proanthocyanidin-ffee m u ta n t cultivars m aintained
sim ilar NH3 concentrations, (35.0, 3 3 .7 ,3 3 .4 m g /1 0 0 m l) com pared to ewes fed th e
norm al b arley (28.2 m g /1 0 0 m l). The presence o f proanthocyanidins in th e n orm al
barley m ay have ren d ered som e o f th e p ro tein unavailable fo r d egradation and
therefore resulted in low er NH3 concentrations in the rum en. It is also possible
th a t overall polyphenolic com pound concentrations in th e n o rm al barley m ay have
h a d a n inhibitory effect o n th e proteolytic activity o f th e m icroorganism s in th e
ru m e n w ith th e sam e result. Since rum inal NH3 is th e m ajo r n itro g en source for
m an y species o f ru m en m icroorganism s, th e level o f NH3 m ain tain ed as a resu lt o f
feeding these diets is im portant. The values rep o rted in this stu d y are w ith in th e
range considered to be adequate for m axim um m icrobial g ro w th (Odle and Schaefer,
1987).
P artitioning of th e nitro g en fraction in th e duodenum indicated differences
in n itro g en flow to th e sm all intestine in ew es due to diet fed (T able 12). D uodenal
crude p ro te in flow differed am ong ew es ( P c . 05) w ith values ran g in g from 101.7
g /d a y (T ron ANT 2 31) to 128.7 g /d a y (G unhild ANT 2 4 6 ).
Ewes fed co m an d
34
G unhild ANT 24 6 show ed sim ilar CP flow to th e duodenum . Crude p ro tein flow in
ew es fed c o m o r G unhild ANT 246 w ere g re a ter ( P c .0 5) th a n in ew es fed tro n ANT
231 w hich w ere sim ilar to th e flow found in Klages- an d A dvance ANT 534-fed
ew es. M organ e t al. (19 8 9 ) reported values o f 116.4 and 1 2 5 .0 g /d a y in sheep fed
h ig h b arley diets o f w hole grain.
F u rth er analysis o f th e duodenal contents indicate sim ilar (P > .1 ) co ncentra­
tions o f am m onia n itro g en (NH3-N) (Table 11). D uodenal NH3-N concentrations
w ere num erically g re a ter in th e ew es fed tw o o f th e proanthocyanidin-free m u ta n t
barleys th a n fo r those fed th e norm al b arley o r com . C oncentrations o f duodenal
NH3-N ran g ed from 8.0 m g /1 0 0 m l in ew es fed G unhild ANT 2 4 6 to 6.5 m g /1 0 0
m l for ew es fed Klages.
Flow o f m icrobial crude p ro tein (MCP) p er day Was n o t significantly
different (P > .0 1 ) am ong ew es as a resu lt o f th e diet fed (T able 12). Daily flow
ranged from 14.6 g M C P/day (com ) to 18.3 g /d a y (G un ANT 2 4 6 ).
Kay e t al.
(19 7 2 ) an d Spicer e t al. (1986) rep o rted g re a ter bacterial CP in th e abom asum o f
steers fed barley th a n those fed com . In this study, ew es fed th e barley cultivar,
T ron ANT 231, produced num erically less MCP th a n th e o th e r barleys. Based o n
in vitro purine accum ulations, the h ig h er MCP flow for ew es fed G unhild ANT 2 46
and A dvance ANT 5 3 4 m ight have b een predicted. Both cultivars produced th e tw o
greatest in vitro purine accum ulations an d also delivered equally h ig h levels o f MCP
to th e sm all in testine in th e m etabolism study.
35
The rem aining nitro g en fraction in th e digesta is assum ed to be feed p ro tein
w hich escaped d egradation in th e ru m en (ESCP). The am o u n t o f ESCP differed
( P c .O l) am ong treatm en ts w ith ew es fed th e co m diet receiving m ore ( P c .O l)
ESCP th a n ew es fed th e barley diets. Values ran g ed from 4 .9 g /d a y (Advance ANT
2 46) to 30.5 g /d a y (com ).
TABLE 12. EFFECTS OF TREATMENT DIETS ON DAILY FLOW
OF CRUDE PROTEIN (CP)3 ESCAPE PROTEIN (ESCP) AND
MICROBIAL CRUDE PROTEIN (MCP) TO THE SMALL INTESTINE.
Diets3
Item
KLA
CP (g /d )
ESCP (g /d )
MCP (g /d )
ADV
GUN
TRON
CORN
SEb
1 1 3 .7cd 113.7cd 1 2 8 .7d 1 0 1 .7C
9 .0e
4 .7 e 12.6e 1 2 .8e
18.6
18.3
14,9
17.1
123.6d
30 .5 f
14.6
6.8
3.6
1.5
a KLA = Klages3 ADV = Advance ANT 534, GUN = G unhild ANT 2 46
TRON = T ron ANT 231
b Pooled stan d ard error
cdM eans in row s w ith different superscripts differ, P < .05.
efM eans in row s w ith different superscripts differ, P < .01.
M icrobial efficiency (MOEFF) differed (P c .O l) am ong ewes fed th e
different diets (Table 13). M easured in g m icrobial p ro tein pro duced p er 100 g OM
digested, m icrobial efficiency serves to characterize th e rum inal environm ent created
by a feed. MOEFF values ranged from 13.3 to 21.4. M icrobial efficiency in ew es
fed th e G unhild ANT 24 6 (21.4) barley diet w as g reater ( P c . 0 5) th a n MOEFF in
ew es fed c o m (13.3) o r T ron ANT 231 (1 4 .2 ). Ewes fed th e Klages and Advance
36
ANT 5 3 4 diets h a d efficiencies o f 17.6 and 21.0, respectively, com pared w ith
MOEFF associated w ith feeding co m (1 3 .3 ).
TABLE 13. EFFECTS OF TREATMENT DIET ON MICROBIAL EFFICIENCY (MOEFF)
(g MICROBIAL PROTEIN PRODUCED/lOO g ORGANIC MATTER DIGESTED.)
Diets3
Item
KLA
ADV
GUN
MOEFF
17.6cde
2 1 .Ode
21.4^
TRON
14.2cd
CORN
13.3cd
SEb
1.58
a KLA = Klages, ADV = Advance ANT 534, GUN = G unhild ANT 246
TRON = T ron ANT 231
b Pooled stan d ard error
M eans in ro w w ith different superscripts differ ( P c .05).
Efficiency associated w ith th e feeding o f Klages (1 7 .6 ) a n d T ron ANT 231
(1 3 .3 ) is as low ( P c .05) as th a t associated w ith feeding co m (1 4 .2 ). The m icrobial
response to G unhild ANT 246 an d Advance ANT 5 34 is also notew orthy.
It is
possible th a t th e low er ru m en digestibility o f th e starch in G unhild ANT 2 4 6
provides a sustained energy supply to coincide w ith p ro tein degradation. A lthough
Spicer e t al. (1986) rep o rted greater ( P c . 05) MN in th e abom asum o f steers fed
b arley diets th a n for co m diets, no differences in MOEFF w ere found.
M icrobial efficiencies listed in NRC (1 9 8 4 ) range from 7.7 to 2 7 .0 g
m icrobial p ro te in /1 0 0 g OM digested, w ith h ig h er values generally associated w ith
roughage diets. Several studies in w hich b arley w as fed to sheep rep o rted MOEFF
values o f 16.3, 11.3 an d 8.1 M C P/100 g OM (Van Soest, 1 9 8 2 ).
Czerkaw ski
(19 8 6 ) sum m arized 65 individual studies according to m ethods o f m easurem ents o f
37
m icrobial synthesis. M ean efficiencies ran g ed from 17.5 -22.4 M C P /100 g OM. This
sum m ary did n o t include inform ation reg ard in g types o f diets. H ynd and A lden
(1 9 8 5 ) suggest MOEFF is m ore variable in sheep fed high co n cen trate barley an d
c o m diets th a n forage diets.
In o rd e r to fulfill th e objectives o f this study, co rrelatio n coefficients w ere
g en erated to describe th e relationship b etw een in vitro an d in vivo results. Since
results from th e in situ DMDR evaluation w ere inconclusive, th e association b etw een
in vitro DMDR an d rum inal starch digestibility w as evaluated.
(r= .6 2 ) w as n o t significant (P = .3 8 ).
The correlation
The association b etw ee n in vitro p u rin e
accum ulation an d duodenal m icrobial n itro g en (r= .5 3 ) w as n o t significant (P = .4 6 ).
The v ariatio n associated w ith anim al studies and m any in vitro procedures is
reflected in th e lack of significance o f these correlations.
In spite o f th e variation, this stu d y serves to illustrate cultivar effects o n th e
digestive physiology o f barley w h en fed to rum inants.
W ithin this group o f
cultivars, ranges o f values w ere expressed fo r im p o rtan t physiological responses in
th e anim als treated . This study dem onstrates po ten tial differences in th e value o f
b arley cultivars in tended for ru m in an t feed.
38
CHAPTER 5
CONCLUSIONS
Based u p o n th e results from th e in vitro study, it can be concluded th a t
differences exist am ong barley cultivars w h ich m ay have a m easurable effect u p o n
th e utilizatio n o f th e grain by rum inants.
The results o f this stu d y dem onstrate
effects o f cultivars a n d /o r chem ical constituents o n in vitro DMDR and estim ated
m icrobial yields.
A lthough in situ DMDR d ata from this w as inconclusive, I believe th e sam e
procedure can be successfully used in fu tu re studies w ith som e m in o r m odifications.
The freq u en t collection of bags necessary to describe a DMDR curve m ay have
interfered w ith norm al ferm entatio n p attern s. The n u m b er o f bags initially placed
in th e ru m e n m ay have restricted free m ovem ent o f th e bags an d th e circulation o f
ru m e n fluid to th e bags. Several steps m ight be tak en to im prove th e procedure fo r
sheep studies.
1. The bags should be m oistened in McDougaTs buffer before placing th e m
in th e rum en. This should decrease th e tim e required for ru m e n fluid to en ter th e
bags.
2. If one cultivar can be evaluated in tw o anim als sim ultaneously, freq u en t
b ag collections could be m ade by a ltern atin g anim als a t each successive tim e
interval. This should also allow in cu b atio n o f few er bags in each anim al.
39
The use o f cattle ra th e r th a n sheep w o u ld allow suspending th e bags fa rth e r
a p art in th e rum en. This w ould im prove circulation o f fluid aro u n d th e bags an d
w ou ld decrease th e overall im pact o n th e ru m en o f freq u en t collections. It is m y
feeling th a t th e size o f th e sheep ru m en is to o small for such intensive sam pling.
I believe ferm en tatio n in th e bags w as p rem atu rely ceased due to th e creation o f a
m icro-clim ate w ith in th e bag.
A lthough in vivo starch digestibilities ap p ear to su p p o rt in vitro DMDR., no
significant correlation w as found betw een th e in vitro results an d th e results o f th e
m etabolism trial. In fu tu re studies, this correlation m ay b e established.
D ata from this study indicate th a t a range o f values fo r th e rum inal
digestibility an d in testinal flow o f starch m ay be expected am o n g barley cultivars.
The ran g e in duodenal starch flows as percentages o f starch in tak e suggest th a t
starch utilizatio n by ru m en m icroorganism s differs am ong cultivars. The results
rep o rted here suggest th a t som e barley cultivars m ay be com parable to c o m as
sources o f energy for rum inants.
F u rth er investigation in to th e specific n a tu re o f
th e starch in th ese cultivars m ay be o f value in predicting h o w efficiently ru m in an ts
w ill utilize barley starch.
Site o f p ro tein digestion in barley cultivars w as show n to differ. A lthough
results from th e in vitro study suggested th a t ferm en tatio n o f b arley cultivars results
in varying m icrobial yield, no significant correlation w as fo u n d b etw een in vitro
purine accum ulation an d duodenal MCP flow.
P artitioning o f th e nitrogenous
40
contents o f th e sm all intestine indicated differences in th e source o f p ro tein supplied
to th e anim al for digestion and ab sorption a t th e sm all intestine.
The barleys used in this stu d y w ere selected in p a rt fo r th e presence o f
genetic blocks preventing synthesis o f proanthocyanidins. If th e elevated rum inal
NH3 in th e anim als fed th e m u ta n t cultivars is assum ed to be indicative o f increased
p ro tein degradation, th e n it can be inferred th a t proanthocyanidins are in terfering
w ith th e use o f th e p ro tein in th e n orm al barley, Klages. The MCP flow an d th e
MOEFF d a ta suggest, how ever, th a t th e presence o r absence o f p roanthocyanidins
alone is n o t a n adequate predictor o f th e influence o f these com pounds o n p ro tein
use by rum inants.
The specific type o f phenolic com pounds found in th ese cultivars w ere n o t
know n.
The in vitro study indicated significant effects o f to ta l polyphenolic
com pounds on m icrobial yield and perhaps o n m icrobial activity. A m ore detailed
description o f th e phenolic com pounds p resen t in th e cultivars an d th e ir specific
effects o n th e ru m en m icrobial pop u latio n in vivo m ay provide a basis for develop­
m en t o f cultivars p articularly supportive o f ru m en m icroorganism s.
U ltim ately, adequately feeding ru m in an t anim als requires first m eeting th e
specific needs of th e rum inal m icroorganism s.
The MOEFF d a ta in this stu d y
suggest n o t only th a t cultivars differ in th e ir influences o n ru m in al m icroorganism s,
b u t th a t som e cultivars ap p ear to have a m ore favorable effect o n th e rum inal
environm ent th a n com .
41
Finally, recognizing th a t this stu d y utilized only a sm all n u m b er o f cultivars
from a w ide an d varied population, I believe this w o rk serves to illu strate th e
p o ten tial o f barley as a prim e source o f feed for rum inants. F urther, I believe it is
reasonable to continue this investigation in o rd er to clarify th e results rep o rted here.
42
LITERATURE CITED
A astrup, S., H. O utrup and K. Erdal. 1984. Location o f th e proanthocyanidins in
th e barley grain. C arlsberg Res. Com m un. 49:1 0 5 .
A guilar, A.A. and E.J. D epeters. 1988. M odification for can n u latio n o f duodenum
w ith flexible, t-shaped cannula in goats. Small Rum. Res. 1:73.
Akin, D. 1982. Forage cell w ell d eg rad atio n and p-coum aric, ferulic, and sinapic
acids. Agron. J. 74:424.
Akin, D. an d L.L. Rigsby. 1985. Influence o f phenolic acids o n ru m e n fungi. Agon.
J. 77:180.
Allen, M.S., M.I. M cB um ey an d P.J. V an Soest. 1985. C ation-exchange capacity o f
p la n t cell w alls a t n eu tral pH. J. Sci. Food Agric. 3 6 :1 0 6 5 .
Am an, P an d K. H esselm an. 1984. Analysis o f starch and o th e r m ain constituents o f
cereal grains. Sw edish J. Agric. Res. 14:135.
A.O.A.C. Official M ethods o f Analyses (1 3 th Ed.). 1980. A ssociation o f A nalytical
Chem ists. W ashington, DC.
Bacic, A. and B A . Stone. 1981. Isolation and u ltrastru ctu re o f aleurone cell w alls
from w h e a t and barley. Aust. J. P lant Physiol. 8:453.
Ballance, G.M. and D.J. M anners. 1978. S tm ctu ral analysis and enzym atic
solubilization o f barley endosperm w alls. Carbohyd. Res. 61:107.
B urden, R.L., J.D. Faires an d A C . Reynolds. 1978. N um erical Analysis. Prindle,
W eber & Schm idt, Boston, MA.
Briggs, D.E. 1978. Barley. C hapm an an d Hall, London.
Chesson, A., C.S. S tew art and R.J. W allace. 1982. Influence o f p la n t phenolic acids
on g ro w th and cellulolytic activity o f ru m en bacteria. Appl. Envir. M icrobiol.
4 4 (3 ) :597.
C hurch, D.C. 1986. Livestock Feeds an d Feeding. Prentis-H all Englew ood O ffs, N.J.
Clark, C.K. and M.K. Petersen. 1987. E valuation o f in v itro d ry m atter, n e u tra l
d eterg en t fiber and crude p ro tein ferm en tatio n ra te o f norm al, proanthocyanidin-ffee m u ta n t and cross-line barley. Proc. W est. Sec. Amer. Soc. Anim.
Sci. 3 8 :293.
Cousins, B.W., T.D. Tanksley, D.A. Knave and T. Jebrow ska. 1981. N utrient
digestibility and perform ance o f pigs fed sorghum varying in ta n n in
concentation. J. Anim. Sci. 5 3 :1524.
43
Chung, O.K. an d Y. Pom eranz. 1985. Amino acids in cereal p ro tein s and p ro tein
fractions. In: Finley, J.W. an d D.T. H opkins (Ed.) D igestibility and am ino
acid availability in cereals and oilseeds. Amer. Assoc, o f Cereal Chem., Inc.
St. Paul, M inn, pp 65-107.
Cerkaw ski, J.W . 1986. An in trod u ctio n to ru m en studies. Perm gam on Press
Elmsford, N.Y.
Engstrom, D.F. and G.W. M athison. 1988. Effects o f $
-glucans and other factors
o n th e digestion an d utilization o f b arley by rum inants. 6 7 th Feeder’s D ay
R eport. U niversity o f Alberta, Edm onton, A lberta T6G 2G4.
Fenton, T.W. and J. Fenton. 1979. An im proved procedure fo r th e d eterm ination
ofchrom ic oxide in feed and feces. Can. J. Anim. Sci. 5 9 :631.
Folin5O. an d W .J. Denis. 1912. A n ew (colorim etric) m eth o d fo r th e d eterm in atio n
o f uric acid in th e blood. J. Biol. Chem. 13:469.
French, D. 1973. Chem ical an d physical properties of Starch. J. Anim. Sci.37(4):1048.
French, D. 1973. S tarch utilization in rum inants. J. Anim. Science. 3 7 (4 ): 1048.
French, D. an d W. Y oungquist. I9 6 0 . C rystallization o f starch oligosaccharides:
oligosaccharide-iodine complexes.
A bstract Papers Amer. Ass. Cereal
Chem ists. 4 5 :4 2 .
Graham, H., K. Hesselman, P. @ nan. 1986. Influence of $
-glucanase supplementa­
tio n o n digestion o f a barley-based diet in th e pig gastro in testin al tract.
N utr.R ep.Int. 34:1089-1096.
H arboum e, J.B., T.J. M abry and H. M abry. 1975. The Flavonoids. Academic Press,
N.Y. pp. 54-58.
H arris, L.E. 1970. In vitro dry m a tte r an d organic m a tte r digestion. N u tritio n
research techniques for dom estic an d w ild anim als. Vol. I pp 5051.
Hespell, R.B. and M.P. Bryant. 1979. Efficiency o f ru m e n m icrobial grow th:
Influenceof som e theoretical an d experim ental factors o n Yatp. J. Anim. Sci.
49:1 6 4 0 .
H inm an, D.D. 1979. A com parison o f m altin g vs. feed b arley varieties o n b eef cattle
perform ance. Proc. W est. Sec. Am. SOc. An. Sci. 3 0 :4 9 .
H ofer, P., C. N ew m an, G. W atts, N. Roth, M. El-Negoumy an d R. N ew m an. 1983.
P rotein quality and feed value o f barley. Proc. W est. Sec. Am. Soc. Anim.
Sci. 34: 179-182
H ynd and Alden. 1985. R um en ferm en tatio n p attern , po stru m in al p ro tein flow and
w ool g ro w th ra te o f sheep o n a high-barley diet. A ust. J Agric. Res. 36,
4551-60.
44
Jung, H.J.G. an d G.C. Fahey, Jr. 1983. Interactions am ong phenolic m onom ers
an d in vitro ferm entation. J. D iary Sci. 6 6:1255.
Jung, H .J.G., G.C.Fahey, Jr. and J.E. G arst. 1983. Simple phenolic m onom ers o f
forages and effects o f in vitro ferm en tatio n o n cell w all phenolics. J. Anim.
Sci. 57:1294.
Kang, M.Y., Y. Sugim oto, I. Kato, S. Sakam oto and H. Fuw a. 1985. Some
properties o f large an d sm all starch granules o f b arley (H ordeum V ulgare L.)
Endosperm . Agric. Biol. Chem. 4 9 (5 ), 1291.
Karlsson, R., R. O lered an d A.C. Eliasson. 1983. Changes in starch granule size
d istribution and starch gelatinization properties d u rin g developm ent and
m atu ra tio n o f w h eat, barley, an d rye. Starch. 3 5 (1 0 ) 335.
Kudo, H., K.J. C heng an d J.W . C osterton. 1986. Electron m icroscopic study o f th e
m ethylcellulose-m ediated d etach m en t o f cellulolytic ru m e n bacteria from
cellulose fibers. Can. J. M icrobiol. 33:267.
M ahadevan, S. J.D. Erfle and F.D. Sauer. 1980. D egradation o f soluble an d
insoluble proteins by Bacteroides Amylophilus p ro tease and by ru m e n
m icroorganism s. J. Anim. Sci. 50:7 2 3 .
M alcolm, K.J an d B.R. Moss 1984. C om parative value o f com , barley and a cornbarley m ixture for production in H olstein cows. Proc. W est. Sec. Am Soc.
Anim. Sci. 35:260.
M cBumey, M.I., M.S. Allen and P.J. V an Soest. 1986. Praseodym ium and copper
cation-exchange capacities o f n eu tral-d eterg en t fibres relative to com position
an d ferm en tatio n kinetics. J. Sci. Food Agric. 37:6 6 6 .
M cCleaiy, B.V. an d Glennie-Holmes, M. 1985. Enzymic Q uantification o f (1-3), ( I 4)-$-D -glucan
in barley and M alt. J. Inst. Brew. 91:2 8 5 .
M cDougal, E.L. 1948. Studies on ru m in an t saliva. I. The com position o f sheep’s
saliva. Biochem.J. 43:99.
M ontana A gricultural Statistics. 1987. M ontana D epartm ent o f A griculture. H elena,
MT 59604.
M organ, D.J., H. R yan an d P.K. Upton. 1989. Cereal digestion in th e rum inant. I .
N u trien t passage from th e ru m en an d glucose kinetics in sheep fed un g ro u n d
b arley o r ung ro u n d m aize diets. Irish J. Agric. Res. 2 8 :3 5 .
M orrison, W.R., D C. Scott and J. K arkalas. 1986. V ariation in th e com position and
physical properties o f barley starches. Starch 38:3 7 4 .
M uirhead, S. 1984. Andre, Steptoe, Klages barley for finishing diets com pared.
Feedstuffs. Dec. 3:14.
I
45
M unck, L. 1981. B arley fo r food, feed an d industry. In: Y. Pom eranz and L.
M unck (Ed.) Cereals: a R enew able Resource: T heory an d Practice, pp 427459. Assn Cereal Chem., St. Paul, MN.
N ew m an, C.W. an d C.F. McGuire. 1985. N utritional q uality o f barley. In:
D .C.Rasm usen (Ed.) Barley, A m erican Society o f A gronom y, Crop Science
Society o f Am erica and Soil Science Society o f America, publishers. M adi­
son, W isconsin, pp 403-455.
N ew m an, R.K., C.W. N ew m an, A.M. El-Negoumy, and S. A astrup. 1984. N utritional
quality o f proanthocyanidin-free barley. N utr. Rep. Int. 3 0 (4 ) :809.
Nocek, J. 1988. In situ and o th e r m ethods to estim ate rum inal p ro tein and energy
digestibility: A review . J. D airy Sci. 71:2051.
N ordkvist, E. A.C. Salom onsson, and P. @ man. 1984. D istribution o f insoluble
b o u n d phenolic acids in barley grain. J. Sci. Food A gric. 35:657.
NRC. 1984. N utrient requirem ents o f b eef cattle. Sixth revised Ed. N ational
A cadem y o f Sciences - N ational R esearch Council, W ashington, DC
0 rskov, E.R.,C. F raser an d I. McDonald. 1971. D igestion o f concentrates in sheep.
3. Effect o f ru m en ferm en tatio n o f barley and m aize diets on p ro tein
digestion. Brit. J. N utr. 26:477.
0 rskov, E.R. 1986. S tarch digestion an d utilization in ru m in an ts. J. Anim. Sci.
63:1624.
0 v erlan d , M. 1988. P rotein quality o f n orm al barley cultivars an d th e ir p ro a n th o ­
cyanidin-free m utants. M.S. Thesis. M ontana State U niver. Bozeman, MT.
Odle, J. an d D.M. Schaefer. 1987. Influence o f ru m en am m onia concentration o n
th e ru m en d egradation rates o f b arley and m aize. Br. J. N utr. 57:127.
Preston, R.L. an d M.L. H erlugson. 1980. Barley v ariety an d form in ratio n s
containing variable levels o f roughage for finishing steers. Proc. W est. Sec.
An. Sci. 31:265.
Preston, R.L., D.C. Rule an d W.E. M cReynolds. 1980. Feeding value o f sp ro u ted
w h e a t in cattle finishing rations. Proc. W est. Sec. Amer. Soc. o f Anim. Sci.
3 1 :2 6 9 .
Robinson, P.H., J.G. Fadal, and S. Tam m inga. 1986. E valuation o f m athem atical
m odels to describe n eu tral d eterg en t residue in term s o f its susceptibility to
d egradation in th e rum en. Anim. Feed Sci. Technol. 15:249.
SAS, 1986. Statistical Analysis System. SAS Institute Inc. Cary, NC.
46
Shew ry, P.R., S.W .J. Bright, S.R. Burgess and B.J. Miflin. 1984. A pproaches to
im proving th e n u tritio n al value o f barley seed proteins. In: The Use o f
N uclear Techniques for Cereal G rain P rotein Im provem ent. STI Pub. 664.
V ienna, pp 227-240.
Sm ith, R.H. an d A.B. McAllan. 1974. Som e factors influencing th e chem ical
com position o f m ixed ru m en bacteria. Br. J. N utr. 3 1 :2 7 .
Spicer, L , B. T heurer an d T.H. Noon. 1981. P rotein digestion o f sorghum grain,
b arley and co m based diets b y b e ef steers. Proc W est. Sec. Arner. Soc o f
Anim. Sci. 32:53.
Spicer, L.A., C.B. T heurer, J. Sow e and T.H. N oon. 1986. R um inal an d post-rum inal
utilizatio n o f n itro g en and starch from sorghum grain-, com - and barleybased diets by b eef steers. J. Anim. Sci. 62:521.
T heodorou, M.K., D.J. Gascoyne, D.E. Akin an d R.D. H artley. 1987. Effect o f
phenolic acids an d phenolics from p la n t cell w alls o n rum enlike ferm en tatio n
in consecutive b a tch culture. Appl. Envir. M icrobiol. 5 3 (5 ):1 0 4 6 .
T heurer, B.C. 1986. G rain processing effects o n starch u tilizatio n by rum inants.
J.Anim. Sci. 63:1649.
Thom ke, S., M. R undgren an d K.E. H esselm an, 1980. The effect o f feeding h ig h
viscosity barley to pigs. 3 1 st E uropean Association o f A nim al Production,
M unich, pp 1-5.
T ruelson, E. 1984. D eterm ination o f flavonols (tannins) in b arley grains.Tidsskr.
Planteavl. 8 8 (4 ) :387.
Varel, V.H. an d H.G. Jung. 1984. Influence o f forage phenolics o n cellulolytic
bacteria an d in vitro cellulose degradation. Can. J. Anim. Sci. 64(S u p p l.):3 9 .
V an Soest, P.J., N utritional Ecology o f th e R um inant.
Ithaca, NY.
Cornell U niversity Press.
V an Soest, P.J. an d J.B. R obertson. 1980. Systems o f analysis o f evaluating fibrous
feeds. In: W .J. Pigden, C.G Balch, M ichael G raham (Ed.) Standardization
o f A nalytical M ethodology for Feeds, pp 49-60. Int. Res. Dev. Ctr. Pub.
N o .l3 4 e . O ttaw a, Canada.
v o n W ettstein, D., B. Jende-Strid, B. A hrenst-Larsen and K. Erdal. 1980. Proanthocyanidinfree barley prevents th e form ation o f b eer haze. MBAA Technical
Q u arterly 1 7 (1 ):1 6 .
W aldo, D.R. 1973. Extent and p artitio n o f cereal grain starch digestion in ru m i­
n an ts. J. Anim. Sci. 37:1062.
W einges, K. an d F.W. N ader. 1982. Proanthocyanidins. In: Pericles M arkakis (Ed.)
A nthocyanins as Food Colors, pp 93-124. Academic Press, Inc., NY.
47
W eltzien, E.M. and F.X. A herae. 1987. The effects o f anaerobic storage an d p ro ­
cessing o f high m oisture barley o n its ileal digestibility b y , and perform ance
of, grow ing sw ine. Can. J. Anim. Sci. 67:829.
Zinn, R A . an d F.N. O w ens. 1986. A rap id procedure o f p u rin e m easurem ent an d its
use fo r estim ating n e t rum inal p ro tein synthesis. Can. J. Anim. Sci. 66:1 5 7 .
'V'ir
f
v
48
APPENDIX
TABLE 14. ARRANGEMENT OF BARLEY CULTIVARS
IN VITRO FERMENTATION RUN SCHEDULE
R un
Cultivars
=
= ,=
1
Klages, CA 990, G u n M d 246, *
2
A dvance ANT 534, *, *, *
3
M anker ANT 563, ANT 13 /R u p al, T ron ANT 2 3 1 , *
4
Klages, ANT 13/N ord ah l, *, *
5
Klages, *, *, *
6
Advance ANT 534, M anker ANT 563, A N T 13 /R u p al, A N T 13 /N o rd a h l
7
M anker ANT 563, Klages, CA 990, T ron ANT 231
8
Klages, ANT 13/N ord ah l, G unhild ANT 246, T ron ANT 231
9
Advance ANT 534, ANT 13 /R u p al, CA 990, G unhild ANT 246
* = C ultivars n o t evaluated in this study.
TABLE 15. LEAST SQUARES ANALYSIS OF VARIANCE FOR RUMEN
DIGESTIBILITY OF DRY MATTER AND ORGANIC MATTER
Item
df
D rv M atter
M ean
Square
T reatm ent
Ewe
Period
E rror
4
4
4
12
149.3
140.0
134.0
30.0
P
0.01
0.02
0.02
O rganic M atter
M ean
df
Square
P
4
4
4
12
5 5 .7
1 42.5
1 09.2
2 3 .5
0.11
0.01
0.02
49
TABLE 16. LEAST SQUARES ANALYSIS OF VARIANCE FOR DRY MATTER
AND ORGANIC MATTER FLOW TO THE DUODENUM
Item
df
T reatm ent 4
Ewe
4
Period
4
E rror
12
DM
M ean
Square
6325.5
15575.5
12489.8
2964.3
P
df
0.13
0.01
0.02
4
4
4
12
OM
M ean
Square
15644.1
6 5 4 4 .4
1 2 5 0 4 .0
2 8 8 1 .3
P
0.01
0.12
0.02
TABLE 17. LEAST SQUARES ANALYSIS OF VARIANCE FOR PH AND VISCOSITY
OF RUMEN FLUID IN EWES
Item
df
pH
M ean
Square
0.031
0.051
0.076
0.031
T reatm ent4
Ewe
4
Period
4
E rror
12
P
0 .44
0.22
0.1 0
df
4
4
4
12
Viscosity
M ean
Square
3 .43
3 .93
1 2 .0 4
2 .9 4
P
0.37
0.31
0.03
TABLE 18. LEAST SQUARES ANALYSIS OF VARIANCE FOR RUMINAL
STARCH DIGESTION AND STARCH FLOW TO THE DUODENUM
Item
T reatm ent4
Ewe
4
Period
4
E rror
12
df
D igestion
M ean
Square
2 19.0
120.1
154.4
24.2
P
< 0 .0 1
< 0 .0 1
< 0 .0 1
df
4
4
4
12
Flow
M ean
Square
2 2 2 .8
570.1
4 3 6 .6
23 .5
P
0.800
0.111
< 0 .0 1
50
TABLE 19. LEAST SQUARE ANALYSIS OF VARIANCE FOR FLOW OF
CRUDE PROTEIN (CP) AND ESCAPE PROTEIN (ESCP) TO THE DUODENUM
Item
df
T reatm ent4
Ewe
4
Period
4
E rror
12
CP
M ean
Square
546.1
1227.4
9 7 3.6
234.0
P
0.11
0.01
0.02
df
4
4
4
12
ESCP
M ean
Square
498.1
86.5
3 0 6 .5
6 3 .7
P
< 0 .0 1
0.30
< 0 .0 1
TABLE 20. LEAST SQUARES ANALYSIS OF VARIANCE FOR FLOW OF
MICROBIAL CRUDE PROTEIN (MCP) TO THE DUODENUM
AND MICROBIAL EFFICIENCY (MOEFF)
Item
df
MCP
M ean
Square
670.5
2105.3
1676.0
4 4 0 .0
T reatm ent4
Ewe
4
Period
4
E rror
12
P
0.0
0.0
0.0
df
4
4
4
12
MOEFF
M ean
Square
6 9 .4
9 9 .4
54 .8
12.5
P
0.02
0.01
0.01
TABLE 21. LEAST SQUARES ANALYSIS OF VARIANCE FOR CONCENTRATION OF
RUMINAL AMMONIA AND DUODENAL AMMONIA
Item
df
T reatm en t 4
Ewe
4
Period
4
E rror
12
R um inal NH3
M ean
Square
60.3
138.3
543.2
117.5
P
0.73
0.3 6
0.02
df
4
4
4
12
D uodenal NHo
M ean
Square
1.9
12 .6
11.6
1.9
P
0.45
< 0 .0 1
< 0 .0 1
51
TABLE 22. LEAST SQUARES ANALYSIS OF VARIANCE FOR IN VITRO
DRY MATTER DISAPPEARANCE RATE (DMDR) AND
IN VITRO PURINE YIELD OF BARLEY CULTIVARS
Item
Barley
R un
df
7
8
IVDMD
M ean
Square
1.9
21.9
P
.12
< .0 1
df
7
8
Purines
M ean
Square
.66
6.1 0
P
.01
< .0 1
MONTANA STATE UNIVERSITY LIBRARIES
762 101 8800 9
HOUCHEN^X
LTD )
UTICA/OMAHA 7
NE.
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b in d e r y