162 leaves printed on single pages, preliminary pages i- vii and numbered pages 1-152. Includes bibliography and abbreviations. / Digitized at 600 dpi grayscale to pdf format (OCR), using a Bizhub 250 Konica Minolta Scanner. / Thesis (PhD(Agric))--University of Stellenbosch, 2000. / ENGLISH ABSTRACT: Maize, forage sorghum, lucerne, oats, barley and triticale are the most common silage crops in
South Africa, while tropical grasses like Eragrostis curvula and Digitaria eriantha are ensiled
to a lesser extent. The aim of this study was to determine the effect of adding a lactic acid
bacterial inoculant to E. curvula, D. eriantha, lucerne, forage sorghum, maize and oat silage.
The effect of the addition of a lactic acid bacterial inoculant when ensiling E. curvula on the
fermentation dynamics during ensiling and the aerobic stability of the silage was determined. The
addition of the lactic acid bacterial inoculant to E. curvula at ensiling resulted in a more rapid
lowering in pH and improved preservation. Inoculated silage had a higher lactic acid content, less
protein breakdown and a lower butyric acid content compared to that of the control silage. Both
silages were stable when exposed to air for five days.
Digitaria eriantha was ensiled, with or without the addition of a lactic acid bacterial inoculant
containing Lactobacillus plantarum. Streptococcus faecium and Pediococcus acidilactici
together with the enzymes, cellulase, hemicellulase and amylase. The addition of the inoculant
resulted in a more rapid drop in pH, a higher level of lactic acid, an increase in the number of
lactic acid bacteria, less protein breakdown and lower numbers of enterobacteria, clostridial
spores, yeast and mould compared to the control silage. Digitaria eriantha hay, control and
inoculated silage diets were fed to 24 Merino rams (n = 8 per treatment) to determine intake and
digestibility. The intake of diets consisting of 90.9% D. eriantha hay, control silage or inoculated
silage, differed significantly (p<0.05) at 1395, 1540 and 1848 g DM/day, respectively. The in vivo organic matter digestibility (glkg) of D. eriantha hay, untreated silage and inoculated silage
diets was 561, 546, 574, respectively. The addition of the bacterial inoculant when ensiling D.eriantha resulted in better preservation, improved aerobic stability, as well as a higher in vivo
organic matter digestibility and intake of D. eriantha silage.
The addition of an inoculant or molasses to lucerne (Medicago sativa), ensiled in laboratory silos
was investigated. The addition of the additives resulted in an increased preservation rate as
indicated by a more rapid lowering of pH, a faster rate of lactic acid production and less protein
breakdown compared to control silage. The inoculant was more effective than the molasses in
improving the rate of preservation. The aerobic stability of lucerne silage was not affected by
inoculation or the addition of molasses. The addition of an inoculant to wilted big bale lucerne
silage was studied. The inoculant improved silage quality as indicated by a lower pH, higher
lactic acid content, lower ammonia nitrogen content and lower level of butyric acid in inoculated
silage compared to the control lucerne silage. The composition of big round bale lucerne silage
differed markedly from that of lucerne ensiled in laboratory silos as the former had a higher pH,
ammonia nitrogen, butyric acid and acetic acid content and a lower lactic content.
Whole crop forage sorghum cultivar FS2 was harvested at the late bloom (20.7% DM) and soft
dough (28.9% DM) stages of maturity and ensiled in laboratory silos with the addition
of commercial silage inoculants. At both stages of maturity the inoculants caused a more rapid rate
of pH decline and a higher amount of lactic acid production. All the silages were well preserved.
Silages of the sorghum ensiled at the late bloom stage with all treatments were stable after 5 days
of aerobic exposure, whereas sorghum ensiled at the soft dough stage with the addition of the
inoculants deteriorated upon aerobic exposure. It is concluded that addition of lactic acid
bacterial inoculants to mature sorghum at ensiling might impair the aerobic stability of the silage.
The yield, nutritional value and production potential of silage made from twenty one maize
hybrids was compared. It was concluded that maize hybrids did differ in metabolizable energy
content, rate of digestion, predicted intake and predicted milk production potential. The content
of NDF and ADF did not differ between the maize hybrids used in this study and could therefore
not be used to predict nutritional value or production potential.
Maize was harvested at the hard dough stage and ensiled with or without the addition of a lactic
acid bacterial inoculant in laboratory silos and in 210 litre drums. The adding of the inoculant
to maize at ensiling did not result in a more rapid drop in pH and higher levels of lactic acid. The
intake and growth of South African Mutton Merino lambs fed inoculated and untreated maize
silage diets was determined. The average daily gain of lambs fed a diet consisting of either 60%
control or inoculated maize silage over a growth period of 60 days was 239 ± 26 and 255 ± 44
g/day, respectively. Although the laboratory study showed very little effect of adding a lactic acid bacterial inoculant to maize at ensiling, lambs tended to consume more of the inoculated silage.
In the second study the effect of the addition of a lactic acid bacterial inoculant with an enzyme
to maize at ensiling on the fermentation dynamics during ensiling, aerobic stability of the silage,
the intake, milk production and milk composition of Jersey cows fed maize silage diets was
determined. The inoculant did not result in a more rapid lowering of the pH or a more rapid
lactic acid production compared to untreated maize silage made in laboratory silos. Both the
control and inoculated maize silages were well preserved. The addition of the inoculant to maize
at ensiling improved the palatability, intake and the aerobic stability of maize silage compared
to the untreated control maize silage. Milk production, milk composition, live weight and
condition score of Jersey cows was not significantly affected by the addition of the inoculant to
maize silage.
The effect of the addition of an enzyme containing lactic acid bacterial inoculant to big bale
oat (Avena sativa, cv Cederberg) silage on silage composition, silage intake, milk production and
milk composition of Jersey cows was determined. The crop was cut at the bloom stage, wilted
and ensiled in big round bales. The inoculant, Sil-All, was applied during the baling process on
half of the bales. Silages were fed to Jersey cows in an intake and milk production study. Both
the control and inoculated oat silages were well preserved. The inoculated oat silage had a lower
level of butyric acid than the control oat silage. Cows fed the inoculated oat silage produced
more (P=O.05) milk (17.7 kg/day) than cows fed the control oat silage (16.7 kg/day). The
addition of a lactic acid bacterial inoculant to big bale oat silage improved silage composition
and animal performance.
This study clearly showed that the composition of silages made in bunker silos under
commercial farm conditions differ largely from that of silages made in small scale laboratory
silos. When the effect of silage additives on aerobic stability of silage is determined the
evaluation should include studies on large scale bunker silages. Evaluation of silage additives
should include intake and animal production studies. / AFRIKAANSE OPSOMMING: Mielies, voersorghum, lusem, hawer, gars en korog word algemeen as kuilvoer gewasse benut
terwyl tropiese grasse soos Eragrostis curvula en Digitaria eriantha tot 'n mindere mate
ingekuil word. Die doel van hierdie studie was om die invloed van 'n melksuurbakterieseinokulant
op E. curvula-, D. eriantha-, lusem-, voersorghum-, mielie- en hawerkuilvoer te
bepaal.
Die invloed van 'n melksuurbakteriese-inokulant op die fermentasiedinamika en die aerobiese
stabiliteit van E. curvula-kuilvoer is bepaal. Die toediening van die melksuurbakterieseinokulant
tot E. curvula tydens inkuiling het 'n vinniger tempo van pH daling en beter
preservering tot gevolg gehad in vergelyking met kontrole kuilvoer. Inokulant behandelde
kuilvoer het 'n hoer melksuurinhoud, minder protei'en afbraak en 'n laer bottersuurinhoud as
kontrole kuilvoer gehad. Beide kuilvoere was stabiel tydens blootstelling aan lug vir vyf dae.
Digitaria eriantha is ingekuil met ofsonder die toediening van 'n melksuurbakteriese-inokulant
wat Lactobacillus plantarum. Streptococcus faecium en Pediococcus acidilactici sowel as die
ensieme, sellulase, hemisellulase and amilase bevat het. Die inokulant het 'n vinniger tempo van
pH-daling, hoer vlakke van melksuur en melksuurbakterie, minder protei'en afbraak en laer
getalle van enterobakterie, klostridiale spore, giste and swamme in vergelyking met die kontrole
tot gevolg gehad. Digitaria eriantha hooi, kontrole kuilvoer en gei'nokuleerde kuilvoer diete is
aan 24 Merino ramme (n = 8 per behandeling) gevoer vir bepaling van inname en
verteerbaarheid. Die inname van diete wat uit 90.9% D. eriantha hooi, kontrole kuilvoer of
gei'nokuleerde kuilvoer bestaan het, het betekenisvol (p<0.05) verskil en was 1395, 1540 en 1848
gDM/dag, respektiewelik. Die in vivo organiesemateriaal verteerbaarheid (gIkg) vanD. eriantha
hooi, kontrole kuilvoer en geYnokuleerde kuilvoer was 561, 546, 574, respektiewelik. Die
toediening van die bakteriese-inokulant tydens inkuiling vanD. eriantha het beter preservering,
verbeterde aerobiese stabiliteit asook 'n hoer in vivo organiesemateriaal verteerbaarheid van D.
eriantha kuilvoer tot gevolg gehad.
Die effek van toediening van 'n melksuurbakteriese-inokulant en van molasse tot lusem
(Medicago sativa) ingekuil in laboratoriumsilos is ondersoek. Die inokulant toediening en
molasse toediening het die tempo van preservering versnel, die pH het vinniger gedaal, melksuur
is teen 'n hoer tempo geproduseer en minder proteYen afbraak het plaasgevind in vergelyking met
die kontrole kuilvoer. Die tempo van preservering is meer effektief deur toediening van die
inokulant verhoog as deur die toediening van molasse. Die aerobiese stabiliteit van
lusernkuilvoer is nie beYnvloed deur die toediening van inokulant ofmolasse nie. Die effek van
die toediening van 'n melksuurbakteriese-inokulant tot groot rondebaal lusernkuilvoer is
ondersoek. Die inokulant het die kwaliteit van die kuilvoer verbeter en het 'n laer pH, hoer
melksuur, laer ammoniak stikstofen laer bottersuurinhoud in rondebaallusernkuilvoer tot gevolg
gehad in vergelyking met kontrole kuilvoer. Groot rondebaallusernkuilvoer het grootliks verskil
van lusernkuilvoer wat in laboratoriumsilos ingekuil is. Die rondebaal kuilvoer het 'n hoer pH,
hoer ammoniak-stikstof-, bottersuur- en asynsuurinhoud en 'n laer melksuurinhoud gehad as
laboratorium lusernkuilvoer.
Voersorghum kultivar FS2 is op die laat blom (20.7% DM) en op die sagte deeg (28.9% DM)
stadium met die byvoeging van melksuurbakteriese-inokulante ingekuil in laboratoriumsilos.
Toediening van beide inokulante tot sorghum hetop beide die inkuilstadiums gelei tot 'n vinniger
tempo van pHdaling en meer melksuurproduksie. Aile kuilvoere insluitend die kontrole kuilvoer
was goed gepreserveer. Kontrole sowel geYnokuleerde sorghumkuilvoer ingekuil op die laat
blomstadium was stabiel tydens aerobiese blootstelling vir 5 dae. Sorghumkuilvoer ingekuil op
die sagtedeegstadium met die byvoeging van inokulante was onstabiel tydens aerobiese
blootstelling. Die toediening van melksuurbakteriese-inokulante tot sorghum wat op die
sagtedeegstadium ingekuil word kan aerobiese stabiliteit van die kuilvoer grootliks benadeel.
Die opbrengs, voedingswaarde en produksiepotensiaal van kuilvoer gemaak van 21 mielie
hibriede is vergelyk. Verskille in metaboliseerbare energie inhoud, tempo van vertering,
voorspelde inname en voorspelde melkproduksie het tussen mielie hibriede voorgekom. Die
neutraalbestandevesel- en suurbestandeveselinhoud het nie verskil tussen hibriede nie en
derhalwe kon dit nie gebruik word om voedingswaarde ofproduksiepotensiaal te beraam rue. Mielies is op die hardedeegstadium met of sonder die toediening van 'n melksuurbakterieseinokulant
in laboratoriumsilos en 210 liter dromme ingekui!. Die toediening van die inokulant
het geen invloed op tempo van pH-daling ofproduksie van melksuur gehad nie. Die inname en
groei van SA Vleismerino lammers wat 'n dieet bestaande uit 60% kontrole of inokulant
behandelde mieliekuilvoer ontvang het, is bepaa!. Die gemiddelde daaglikse toename van
lammers was 239 ± 26 and 255 ± 44 g/dag vir die kontrole en inokulant mieliekuilvoer dieet
respektiewelik. Alhoewel die laboratoriumstudie weinig verskille tussen die kontrole en die
geYnokuleerde mieliekuilvoer getoon het, het lammers geneig om meer van die geYnokuleerde
mieliekuilvoer in te neem. In die tweede studie met mieliekuilvoer is die effek van toediening
van 'n melksuurbakteriese-inokulant met ensieme, op die ferrnentasiedinamika tydens inkuiling,
die aerobiese stabiliteit van mieliekuilvoer asook die inname, melkproduksie en
melksamestelling van Jersey koeie bepaa!. Die inokulant het nie die tempo van pH daling en
produksie van melksuurverhoog nie en beide kontrole en geYnokuleerde mieliekuilvoerwas goed
gepreserveer. Die toediening van die inokulant tot mieliekuilvoer het die smaaklikheid, inname
en die aerobiese stabiliteit van mieliekuilvoer verhoog in vergeiyking met kontrole
mieliekuilvoer. Melkproduksie, melksamestelling, liggaamsmassa en kondisiepunt van Jersey
koeie is nie betekenisvol beYnvloed deur die toediening van die inokulant tot mieliekuilvoer nie.
Die effek van die toediening van 'n ensiem bevattende melksuurbakteriese-inokulant tot groot
rondebaal hawer (Avena sativa, cv Cederberg) kuilvoer op die samestelling van kuilvoer,
kuilvoerinname, melkproduksie en melksamestelling van Jersey koeie is bepaa!. Die gewas is
gesny op die blomstadium, verwelk en as rondebaalkuilvoer gepreserveer. Die inokulant, Sil-All,
is tydens die baalproses toegedien op die helfte van die bale. Kuilvoere is aan Jersey koeie gevoer
in 'n inname en melkproduksiestudie. Beide die kontrole en geYnokuleerde hawerkuilvoer was
goed gepreserveer. Die bottersuurinhoud van geYnokuleerde hawerkuilvoer was laer as die van
die kontrole hawerkuilvoer. Koeie wat geYnokuleerde hawerkuilvoer gevoer is het meer (P=0.05)
melk (17.7 kg/dag) geproduseer as koeie wat kontrole hawerkuilvoer ontvang het (16.7 kg/dag).
Die toediening van 'n melksuurbakteriese-inokulant het kuilvoer kwaliteit en diereproduksie
verbeter.
Hierdie studie wys duidelike verskille uit tussen kuilvoer wat in bunkersilos onder kommersiele
toestande ingekuil is, en kuilvoer wat in laboratoriumsilos gemaak is. Wanneer die effek van
kuilvoerbymiddels op die aerobiese stabiliteit van kuilvoer bepaal word behoort finale evaluasie
gedoen te word op kuilvoer gemaak in bunkersilos soos onder plaastoestande plaasvind.
Evaluasie van kuilvoerbymiddels behoort inname en diereproduksiestudies in te sluit.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/14770 |
| Date | 12 1900 |
| Creators | Meeske, Robin |
| Contributors | Cruywagen, C. W., University of Stellenbosch. Faculty of Agrisciences. Dept. of Animal Sciences, Jacobs, Ivan |
| Publisher | Stellenbosch : University of Stellenbosch |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | English |
| Type | Thesis |
| Format | 152 leaves : ill. |
| Rights | University of Stellenbosch |
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