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An evaluation of small-scale piggeries in Limpopo Province, South AfricaManchidi, M. J. 03 1900 (has links)
Thesis (MPhil (Animal Sciences. Livestock Industry Management: Pig Science))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: This mini-thesis describes the pig industry in South Africa which consists of a commercial intensive sector and
an extensive sector that is also known as the small scale sector. Challenges in such as, marketing, feed,
housing and genetics of small scale farmers are discussed.
The objective of this study is to identify the problems experienced by the emerging/small scale pig farmers and
to benchmark the production parameters of these farmers. Data was collected using questionnaires, telephone
and site visits to farms/projects. The data collection was grouped into descriptions of small scale piggeries,
feeding strategies, management programs, production parameters, regional constraints, marketing, comparisons
between stud and commercial piggeries.
The results were arranged into the following manner: general, regional constraints, description of small scale
piggery facilities, feeding strategies of small scale farmers, management programs in small scale piggeries,
production parameters of small scale piggeries in the Limpopo province, production parameters of stud and
commercial piggeries, and the management strategy in a commercial piggery.
Those piggeries having 5-30 sow units were interviewed. Results indicate that small scale farmers were found
not to be sustainable in their production. The small scale farmers have no understanding of the pig industry,
genetics and breeding of pigs, feeding strategies, and marketing channels for pigs. Typical problems
experienced are: marketing is only done once or twice a year and not regularly as with any commercial piggery –
a main problem identified here was access to the formal market. Typical production problems experienced were
long farrowing intervals, small litter sizes, late weaning periods and low weaning percentages. This was
attributed not only to mismanagement but also to bad infrastructure. Small scale piggeries typically have low cost
sty’s that have inadequate floors, walls, roofing and very few of the piggeries has sufficient fresh water. Another
problem experienced was poor growth which could be directly linked to the nutrition of the pigs. Most of the feed
fed consisted of kitchen waste as balanced diets were perceived to be too expensive whilst access to suppliers,
and transport (of both feed and pigs off to market) was generally lacking. Another major problem identified by the
producers was insufficient scientific help from Government. Most producers also mentioned that they would
welcome a mentorship program and help with the marketing and sourcing of funds. None the less, the pig
owners all indicated that they wish to continue farming with pigs and that with the right help, they would be able
to be successful. / AFRIKAANSE OPSOMMING: Hierdie werkstuk beskryf die vark industrie in Suid-Afrika wat bestaan uit ‘n kommersiële intensiewe en
ekstensiewe sektor wat ook bekend staan as die klein-skaal sektor. Uitdagings soos bemarking, voer, behuising
en genetika van klein-skaalse boere word bespreek.
Die doel van die studie is om die probleme te identifiseer wat ervaar word deur die opkomende/klein-skaalse
boere asook om die produksie-parameters van die boere te bepaal. Data was versamel deur middel van
vraelyste, telefoonoproepe asook besoeke aan die boere/projekte. Die dataversameling was op verdeel in
beskrywings van klein-skaalse vark eenhede, voerstrategieë, bestuursprogramme, produksie-parameters,
distriksbeperkings, bemarking, en vergelykings tussen stoet- en kommersiële-eenhede.
Die resultate was gesorteer op die volgende manier: algemeen, distriksbeperkings, beskrywing van klein-skaalse
varkeenhede, produksie-parameters van klein-skaalse varkeenhede in die Limpopoprovinsie, produksieparameters
van stoet- en kommersiële varkeenhede, en die bestuurstrategie in ’n kommersiële varkeenheid.
Ondehoude is gevoer met dié eenhede wat tussen 5-30 soê het. Resultate wys dat klein-skaalse boere nie
volhoubaar is in hul produksie nie. Die klein-skaalse boere het geen kennis van die vark bedryf, genetika en teel
van varke, voerstrategieë en bemarking van varke nie. Tipiese probleme wat ervaar word is: bemarking word
slegs een of twee keer per jaar gedoen en nie gereeld soos met kommersiële eenhede nie – die hoof probleem
wat geïdentifiseer is die toegang tot die formele mark. Tipiese produksieprobleme wat hier geïdentifiseer is, was
lang kraam intervalle, klein werpsel groottes, laat speenperiodes en lae speenpersentasies. Dit was as gevolg
van nie net misbestuur nie, maar ook as gevolg van slegte infrastruktuur. Klein-skaalse vark eenhede het
gewoontlik goedkoop varkhokke met onvoldoende bevloering, mure, en dakke en baie min van die eenhede het
genoegsame vars water gehad. Nog ’n probleem wat ondervind is, was die slegte groei van die varke wat direk
gekoppel kan word aan die voeding van die varke. Meeste van die voer het bestaan uit kombuisvullis omdat
gebalanseerde rantsoene beskou was as te duur, terwyl daar oor die algemeen ’n te kort was aan toegang tot
verskaffers en vervoer (van beide voer en varke na die mark). Nog ’n groot probleem wat geïdentifiseer is deur
die produsente was dat daar ’n tekort is aan wetenskaplike hulp van die Regering. Meeste van die produsente
het ook genoem dat hul ’n mentorskapprogram sal verwelkom asook hulp met bemarking en befondsing. Nie te
min, die varkeienaars het almal aangetoon dat hul graag met die varkboerdery sou wil aangaan en dat met die
regte hulp sou hul suksesvol kan wees.
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Fermentation, stability and degradability of whole-crop oat silage ensiled with a commercial inoculantPienaar, Johanni 03 1900 (has links)
Thesis (MScAgric (Animal Sciences))--Stellenbosch University, 2010. / ENGLISH ABSTRACT: South Africa is well-known for periodic dry periods and uncertain rainfall. Ensiling of
crops is a method of preserving forage and ensures feed availability during periods when
the supply of good quality forage is low. Cereal-based silages, especially in the Western
Cape, South Africa, represent a significant proportion of feed consumed by ruminant
animals, particularly high-producyion dairy cattle. However, farmers are still concerned
about the technical challenges of ensiling cereal crops. Previous research done on lactic
acid bacteria (LAB) inoculants used on cereal based silage has indicated a potential for
improving silage fermentation, stability and degradability, thus enhancing feed
conversion and production by ruminants.
Two experiments were conducted to determine the effects of inoculating whole-crop oat
silage with Lalsil® Cereal Lactobacilli (Lactobacillus buchneri (NCIMB 40788) and
Pediococcus acidilactici (CNCM MA 18/5M)) LAB on
(1) silage fermentation,
(2) aerobic stability and
(3) nutritional value of silage ensiled under
a. micro-silos conditions and
b. in a bunker under outdoor conditions of a Mediterranean summer. Oats (Avena sativa, cv SSH 405) were planted on 60 ha under dryland conditions at
Elsenburg in the Western Cape province, South Africa. Whole-crop oats were harvested
at the soft dough stage and length of the chopped material was 9 mm (Day of ensiling –
Day 0).
Chopped whole-crop oats were sampled, mixed thoroughly and divided into two portions.
The Inoculant (Lalsil® Cereal) was applied to one portion to provide 5.79 x 109 colony
forming units (CFU) of LAB per gram of fresh material. In the first experiment twenty -
four glass silos (1.5 L glass jars) (WECK, GmbH u.Co., Wehr-Ofligen, W. Germany)
were filled for each of the control and inoculant treatments. The glass silos were stored
in a dark room in the laboratory at ambient temperature. Three glass silos were opened
for each treatment on days 1, 2, 4, 8, 15, 30, 60 and 102 post-ensiling to determine
fermentation dynamics.
A parallel study was done with the same chopped whole-crop oats using the buried bag
technique in a bunker silo. Whole-crop oats were ensiled in six net bags per treatment
buried in a bunker filled with the same untreated whole crop oats. Bags, attached with
nylon lines (3 m lengths) for easy retrieval were buried at 1m and 2 m depths in the same
bunker. The net bags in the bunker were retrieved after 186 days of ensiling.
Dry matter (DM), organic matter (OM), neutral detergent fibre (NDF), crude protein
(CP), lactic acid levels, pH, water soluble carbohydrates (WSC) and in vitro organic
matter degradability (IVOMD) for both studies were determined. Silage of both
experiments was exposed to aerobic conditions for ten days to determine aerobic
stability. It is concluded that the inoculant Lalsil® Cereal had the effect of reducing the
rate of consumption of WSC during the anaerobic phase and aerobic exposure for both experiments. Silage spoilage due to yeasts and moulds was however more evident with
the inoculated silage due the presence of sugars in the micro-silos experiment. / AFRIKAANSE OPSOMMING: Suid-Afrika is bekend vir droë periodes en wisselvallige reënval. Die inkuiling van
gewasse is ‘n goeie manier om ruvoer te voorsien in tye van droogtes of tekorte.
Kleingraan kuilvoer is veral bekend in die Wes-Kaap, Suid-Afrika en maak ‘n groot deel
uit van die melkkoei se rantsoen. Landbouers is nog steeds bekommerd oor die tegniese
aspekte wanneer dit kom by die inkuil van gewasse. Vorige navorsing het getoon dat die
gebruik van ‘n melksuurbakteriese inokulant saam met die inkuiling van gewasse
moontlik die potensiaal het om fermentasie, stabiliteit en degradering te verbeter en
sodoende voeromset te verbeter.
Twee eksperimente is uitgevoer om die effek van die inkuiling van hawerkuilvoer met
Lalsil® Cereal Lactobacilli (Lactobacillus buchneri (NCIMB 40788) en Pediococcus
acidilactici (CNCM MA 18/5M)) LAB te bepaal op
(1) kuilvoer fermentasie,
(2) aërobiese stabiliteit en
(3) nutriëntwaarde van die kuilvoer ingekuil in
a. mikrosilo’s en
b. in ‘n bunker in die buitelug. Hawer (Avena sativa, cv SSH 405) is op 60 ha droë land geplant op Elsenburg in die
Wes-Kaap, Suid-Afrika. Die hawer is ingekuil tydens die sagte deeg stadium en die
gekapte materiaal was ongeveer 9 mm lank.
Gekapte material was deeglik gemeng en in twee gedeel. Die inokulant (Lalsil® Cereal)
is op die een gedeelte gesproei om 5.79 x 109 kolonie-vormende eenhede (KVE)
melksuurbakterieë per gram vars materiaal te voorsien. Tydens die eerste eksperiment is
24 mikrosilo’s (1.5 L glas silo) (WECK, GmbH u.Co., Wehr-Ofligen, W. Duitsland) vir
elke behandeling vol kuilvoer gemaak. Hierdie mikrosilo’s is gestoor in ‘n donker kamer
teen kamertemperatuur. Drie mikrosilo’s is per behandeling oopgemaak op dag 1, 4, 8,
15, 30, 60 en 102 na inkuiling om die fermentasie-dinamika te bepaal.
‘n Parallelle studie is gedoen met dieselfde materiaal ingekuil in netsakke binne die
bunker. Die materiaal was ingekuil in ses netsakke vir elke behandeling. Nylon toue (3
m) is aan die sakke vasgemaak om die uithaal daarvan op latere stadium te vergemaklik.
Hierdie sakke is ingekuil op verskillende dieptes, 1 m en 2 m in dieselfde bunker. Die
sakke is na 186 dae weer uitgehaal.
Droë materiaal (DM), organiese materiaal (OM), neutraal bestande vesel (NBV),
ruproteïen (RP), melksuurvlakke, pH, water oplosbare koolhidrate (WOK) en in vitro
organiese materiaal verteerbaarheid (IVOMV) vir beide studies is bepaal. Kuilvoer van
beide eksperimente is ook blootgestel aan aërobiese toestande vir 10 dae aan aërobiese
toestande blootgestel om aërobiese stabiliteit te bepaal. Daar is bepaal dat die inokulant
Lalsil® Cereal het die tempo van WOK verbruik verminder gedurende die anaërobies
fase sowel as die aërobiese fase vir beide eksperimente. Kuilvoer wat bederf het as gevolg van giste en swamme was meer sigbaar by die inokulant behandelde kuilvoer as
gevolg van die teenwoordigheid van suikers in die mikrosilo’s.
(Sleutelwoorde: hawerkuilvoer, inokulant, mikrosilo’s, water oplosbare koolhidrate
(WOK), in vitro organiese materiaal verteerbaarheid (IVOMV))
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Breed, transport and lairage effects on animal welfare and quality of Namibian beefLuhl, Juljane 03 1900 (has links)
Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: Namibia by nature is very well suited for livestock production and is a net exporter of beef. Beef is currently
exported to South Africa, the European Union (EU) and Japan while market access to the United States of
America is being explored. Food safety, traceability and lately animal welfare are all aspects which are
requested by Namibians trading partners when exporting meat to those countries. The first two aspects have
been addressed with the introduction of the Farm Assured Namibian Beef scheme (FAN Meat) which also
provides basic guidelines for animal welfare.
Beef in Namibia is produced from extensively managed enterprises which are privately owned and
managed, or state owned and communally utilized. The events of handling and transport are considered
stressful to all animals but especially so to extensively raised animals and their reaction to these events has
the potential to severely infringe on their welfare. The aim of this study was to determine the effect of pre-,
during, and post-transportation handling on animal welfare status under Namibian transport conditions. The
study also investigated the influence of breed on the meat quality of Namibian beef.
The level of bruising recorded on slaughter was used to measure animal welfare. Interviews with
producers were conducted to describe the pre-transport handling. Questionnaires that included variables
considered as important indicators of animal welfare during transport were distributed to truck drivers.
Observations of the off-loading event and animal behaviour were completed in lairage at the export abattoir
in Windhoek. The variables that were identified as high risk factors and had a significant influence on the
level of bruising under Namibian transport conditions include animal factors (i.e. breed type, age, sex,
condition and subcutaneous fat cover), pre-transport handling (i.e. re-branding of animals), transport related
risks (loading density and animals lying down during transit) as well as lairage factors (i.e. fit of truck floor to
off-loading ramp, the way animals moved to holding pens, pen size and minimum environmental
temperatures).
The influence of breed on meat tenderness and water-holding capacity of the Longissimus dorsi
muscle of the four main beef breeds (i.e. Brahman, Bonsmara, Simbrah and Simmental), as well as the
effect of different aging periods on meat quality (i.e. 2, 9, 16, 23, 30 & 37 days post mortem) were
investigated. The Brahman differed significantly (p < 0.05) from the other three breeds in terms of all aging
treatments; with higher Warner-Bratzler shear force values reported for this breed. Interactions between days
post mortem and breed were found for the Simbrah, and Simmental breeds, which may be indicative of a
delayed response to aging of meat samples obtained from Simbrah animals. This can possibly be ascribed
to an increased calpastatin activity in these animals. Meat samples obtained from the Bonsmara steers
showed the highest rate of tenderization, with this effect retained until day 30 post mortem.
Recommendations as pertaining to the ante mortem handling of cattle are made. / AFRIKAANSE OPSOMMING: Namibië word gekenmerk deur toestande wat uitstekend vir diereproduksie is, met die land wat as ‘n netto
uitvoerder van beesvleis beskou word. Vleis word na Suid-Afrika, die Europese Unie (EU) en Japan
uitgevoer, met die moontlikheid van die Verenigde State van Amerika wat as ‘n uitvoermark ondersoek word.
Voedselveiligheid, naspeurbaarheid en dierewelsyn is drie vereistes wat deur die invoerders van Namibiese
vleis daargestel word. Die eerste twee vereistes is reeds deur die implementering van die Farm Assured
Namibian beesvleis skema (FAN Meat) aangespreek, met die skema wat basiese riglyne vir dierewelsyn
voorskryf.
Namibiese beesvleis word geproduseer onder grootskaalse ekstensiewe boerdery omstandighede,
wat of privaat besit en bestuur word, of aan die regering behoort en deur plaaslike gemeenskappe benut
word. Die invloed van hantering en vervoer is besonder stresvol vir diere en in besonder vir diere wat onder
ekstensiewe omstandighede geproduseer word. Omdat diere onder ekstensiewe omstandighede
ongewoond aan hantering en vervoer is, kan dié twee aksies ‘n ernstige impak op die welsyn van sulke diere
hê. Die doelwit van die studie was om die invloed van hantering voor-, tydens en na-vervoer onder
Namibiese vervoertoestande te ondersoek. Die invloed van ras op Namibiese beesvleiskwaliteit is ook
ondersoek.
Die mate van kneusing waargeneem met slagting was as standaard gebruik om die welsynstatus
van diere te bepaal. Onderhoude is met produsente gevoer om inligting oor die pre-vervoer toestande in te
win. Vraelyste wat veranderlikes wat as belangrike indikators van dierewelsyn tydens vervoer beskou kan
word, ingesluit het, is aan vragmotorbestuurders versprei. Waarnemings van die aflaai en verwante
diergedrag was by die houfasiliteite van die uitvoer abattoir in Windhoek, waarnatoe die diere vervoer is,
gedoen. Verskeie hoë risiko faktore wat ‘n betekenisvolle invloed op die mate van kneusing wat tydens
vervoer opgedoen is, gehad het, is in die studie geïdentifiseer. Hierdie faktore het dierverwante eienskappe
(d.i. ras, ouderdom, geslag, liggaamskondisie en onderhuidse vetvoorsiening), voorvervoer hantering (d.i.
herbrandmerk van diere), vervoerverwante risiko’s (d.i. aantal diere per trok kompartement en diere wat
tydens vervoer gaan lê), asook ontwerp van houfasiliteite (d.i. verbinding tussen trokvloer en laaibrug, die
manier wat diere na houkampies beweeg het, grootte van houkampies en lae omgewingstemperature),
ingesluit.
Die invloed van ras op die sagtheid en waterhouvermoë van die Longissimus dorsi spier van die vier
hoof vleisbeesrasse (d.i. Brahman, Bonsmara, Simbrah en Simmentaler), asook verskillende
verouderingstydperke op vleiskwaliteit (d.i. 2, 9, 16, 23, 30 en 37 dae post mortem) van die vier rasse is
ondersoek. Die Brahman het betekenisvol (p < 0.05) van die ander drie rasse in terme van die effek van
veroudering op vleiskwaliteit verskil, met hoë Warner-Bratzler skeursterkte waardes wat vir dié ras
aangeteken is. ‘n Interaksie tussen aantal dae post mortem en ras is gevind vir die Simbrah en Simmentaler
rasse, wat dui op ‘n vertraagde effek van vleisveroudering vir die Simbrah ras, moontlik as gevolg van ‘n
hoër mate van kalpastatien aktiwiteit. Vleismonsters bekom van jong Bonsmara bulle het die grootste mate van versagting getoon, met die voordeel wat waargeneem is tot dag 30 van die post mortem
vleisveroudering.
Aanbevelings betreffende die voorslag hantering van beeste word gemaak.
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Effects of feeding omega-3 fatty acids and vitamin E on the chemical composition and microbial population of broiler meatCoetzee, Gerna (Gertruida Johanna Maria) 04 1900 (has links)
Thesis (MScAgric) -- University of Stellenbosch, 2000. / ENGLISH ABSTRACT: Lipids remain one of the most important nutrients required by broilers. The growing awareness that some Western
societies have too high a dietary ratio of n-6/n-3 polyunsaturated fatty acids is of direct relevance to broiler nutrition and
lipid metabolism. Meaningful quantities of n-3 polyunsaturates have been incorporated into major poultry tissues, so that
the production of broiler meat with high n-3 polyunsaturates becomes advantageous for the broiler industry as they are
perceived as having a 'healthier' lipid profile. Unfortunately, such broiler meat is rather susceptible to oxidative
deterioration, and oxidation often determines shelf life of poultry meat products. The addition of a-tocopherol (vitamin E)
to broiler diets is an effective means of improving the oxidative stability of broiler meat. Elevated a-tocopherol levels in
broiler feeds increase tissue concentrations thereof resulting in improved stability of membranal structures which may be
expected to increase the oxidative stability of broiler meat and meat products.
Three investigations were done at Mariendahl Poultry Research Station in Stellenbosch. The broilers were kept in 1 x 0.4
x 0.5 m cages in a broiler rearing house. All the trials started with day-old chicks, except experiment 1 where 3-week old
broilers were used. At the end of trials 2 and 3 the 6-week old broilers were slaughtered and the carcasses prepared for
chemical analysis.
Experiment 1: Metabolisabie energy of Canola acid oil and Famarol acid oil for broiler chickens.
In trials with 21-day-old male broilers the true metabolisabie energy value, corrected for nitrogen retention (TMEn) was
determined by the balance method for Canala acid oil (CAO) and Famarol acid oil (FAO). The trials were duplicated, each
time using different samples of the two oils from the same source (experiment 1 and 2). Each of the two oils were blended
in two ratios with a basal diet to form the test diets, viz. 100% Basal; 96% Basal: 4% Oil; 92% Basal: 8% Oil. In
experiment 3, 50 % bran was added to the maize to form the basal diet. The balance trials lasted for 3 days after an
adaptation period of 4 days. The TMEn values determined by regression for the broilers of CAO did not differ significantly
(P>0.05) between experiments 1 and 2. However, the value for experiment 3 was significantly (P<0.05) higher than those
for experiments 1 and 2. The TMEn values of FAO also did not differ significantly (P>0.05) between experiments 1 and 2,
although the value for experiment 3 was significantly higher than that of experiment 1. The addition of 50 % bran to the
basal diet in experiment 3 could have stimulated the digestive breakdown process and hence increase the secretion of
digestive enzymes. This could lead to an increase in the utilisation of the test lipid and therefore an increase in the TMEn
value. The TMEn values of CAO differed significantly (P<0.05) from those of FAO for all three the experiments (exp.
1:30.6 ± 0.399 MJ/kg for CAO vs. 25.9 ± 0.441 MJ/kg for FAO; expo 2: 31.0 ± 0.633 MJ/kg for CAO vs. 26.1 ± 0.668 MJ/kg
for FAO: expo 3: 32.1 ± 0.867 MJ/kg for CAO vs. 27.1 MJ/kg for FAO).Experiment 2:
of broilers.
The dietary effects of various combinations of Canala acid oil (CAO, a high level of C18:3n-3 and MUFA) and Famarol
Effects of various dietary n-6/n-3 fatty acid ratios on the perfonnance and body composition
acid oil (FAO, a high level of 18:2n-6 and SFA) on tissue fatty acid composition were studied in broiler carcasses and
abdominal fat pads. From day-old to six weeks, chicks were fed one of six diets containing 100% FAO, 80% FAO-20%
CAO, 60% FAO-40% CAO, 40% FAO-60% CAO, 20% FAO-80% CAO, 100% CAO. There were no statistical differences
(P>0.05) in average daily gain (1.71 ± 0.059 g) or feed conversion ratios (1.97 ± 0.051) among dietary groups. No
statistical differences (P>0.05) were found in the chemical proximate composition of the carcasses for the moisture (66.20
± 0.112 %), protein (17.63 ± 0.484 %), lipid (15.92 ± 1.507 %) and ash (0.95 ± 0.115 %) content among dietary groups.
No statistical differences (P>0.05) were found in the chemical proximate composition of the abdominal fat pads for the
moisture (28.77 ± 0.112 %), protein (3.03 ± 0.484 %), lipid (63.32 ± 9.789 %) and ash (0.45 ± 0.135 %) content among
dietary groups. With the increase in dietary CAO levels, the percentages of C18:2n-6 and C20:4n-6 in the carcasses
decreased respectively with 1.78 % from 20.88 % and 0.35 % from 1.05 %, whilst C18:3n-3 and longer chain n-3 fatty
acids such as C20:5n-3 and C22:6n-3 increased respectively with 2.25 % from 1 %, 0.1 % from 0.1 % and 0.67 % from
0.2 %. The same tendency was seen in the abdominal fat pads where C18:2n-6 and C20:4n-6 decreased respectively
with 1.55 % from 20.75 % and 0.98 % from 1.2 % with an increase in dietary CAO, whilst C18:3n-3, C20:5n-3 and
C22:6n-3 increased respectively with 2.13 % from 1.15 %, 0.45 % from 0.03 % and 0.95 % from 0.05 %. The n-3/n-6 ratio
in the carcasses and abdominal fat pads increased respectively with 0.16 % from 0.06 % and 0.19 % from 0.06 % with an
increase in dietary CAO. These results clearly indicate that dietary CAO enriched with a-linolenic acid lower saturated
fatty acids respectively in broiler carcasses and abdominal fat pads with 4.88 % from 31.6 % and 10.63% from 31.1 %,
whilst increasing monounsaturated fatty acids with 3.87 % from 44.95 % and 7.25 % from 46.7 % respectively and
polyunsaturated fatty acids with 1.02 % from 23.45 % and 2.38 % from 23.2 % respectively.
Experiment 3: Effect of dietary vitamin E on the performance of broilers and oxidative stability, colour,
microbiological stability, fatty acid composition and pH of broiler meat during refrigerated and frozen storage.
Experiment 1 was carried out with 220 one-day-old broiler chicks to evaluate the effect of eleven concentrations of vitamin
E (0, 20, 40, 60, 80, 100, 120, 140, 160, 180 and 200 mg a-tocopheryl acetate 1 kg diet) on their production performance
and the oxidative stability of their frozen broiler carcasses. The diets with vitamin E levels 0 to 100 mg were fed from
day-old to 42 days of age while the diets with vitamin E levels 120 to 200 mg were fed from 21 to 42 days of age. The
oxidative stability, evaluated by thiobarbituric acid reactive substances (TBARS) values, was determined after 30, 90, 120
and 150 days of storage at -20°C. There were no statistical differences (P>0.05) in average daily gain (1.85 ± 0.111 g) or
feed conversion ratios (2.29 ± 0.397) among dietary groups. TBARS values increased significantly (P<0.05) with
increasing time of storage (basal diet: day 30 = 1.71 ± 0.51; day 150 = 4.89 ± 0.51), but decreased significantly (P<0.05)
with increasing vitamin E levels (day 150: basal = 4.89 ± 0.51; 100 mg / kg = 1.09 ± 0.27). Experiment 2 was carried out
with day-old broiler chicks to evaluate the effect of five concentrations of vitamin E (0, 40, 80, 120 and 160 mg atocopheryl
acetate / diet) on their performance and the oxidative stability of their refrigerated carcasses. The experimental
diets were fed from day-old to 42 days of age. The oxidative stability, evaluated by TBARS values, colour deterioration
and microbiological stability were determined after 0, 4, 8, 10 and 12 days of storage at 4°C. Fatty acid analysis was done
on the samples of days 0 and 12. There were no statistical differences (P>0.05) in average daily gain (1.88 ± 0.117 g) or
feed conversion ratios (2.37 ± 0.467) among dietary groups. TBARS values increased significantly (P<0.05) with
increasing time of storage, but decreased significantly (P<0.05) with increasing vitamin E levels. There were no statistical
differences (P>0.05) in colour measurements for L* (44.97 ± 0.662), a* (5.23 ± 0.315) or b* (12.76 ± 0.321) values
between treatments. Microbiological counts increased significantly (P<0.05) over time with vitamin E concentration
showing no effect. There were no statistical differences (P>0.05) for any of the fatty acid groups measured (SFA: Day 0 =
26.1 ± 1.13%, Day 12 = 26.1 ± 1.17%; MUFA: Day 0 = 41.4 ± 1.46%, Day 12 = 40.2 ± 2.28%; PUFA: Day 0 = 32.4 ± 1.95%, Day 12 = 33.8 ± 2.52%) among dietary groups. Similarly, none of the fatty acids showed statistical significant
(P>0.05) concentration changes over time. There were no statistical differences (P>0.05) in pH (6.01 ± 0.206) among
dietary groups. / AFRIKAANSE OPSOMMING: Lipiede is steeds een van die mees belangrike voedingstowwe wat deur braakuikens benodig word. Die groeiende
bewuswording dat sekere Westerse gemeenskappe 'n te hoë verhouding van n-6/n-3 poli-onversadigde vetsure in hul
dieet het, is direk relevant vir braaikuikenvoeding en lipiedmetabolisme. Betekenisvolle hoeveelhede n-3 polionversadigde
vetsure is geïnkorporeer in die belangrikste hoendersnitte, met die gevolg dat die produksie van
braaikuikenvleis met hoë n-3 poli-onversadigde vetsure voordelig is vir die braaikuikenindustrie en geag word 'n meer
"gesonde" beeld te hê. Ongelukkig is sodanige braaikuikenvleis redelik vatbaar vir oksidatiewe bederf, en oksidasie
bepaal dikwels die rakleeftyd van hoendervleisprodukte. Die byvoeging van a-tokoferol (vitamine E) by braaikuikendiëte
is 'n effektiewe manier om die oksidatiewe stabiliteit van braaikuikenvleis te verbeter. Verhoogde a-tokoferol vlakke in
braakuikenvoere verhoog die weefselkonsentrasie wat verhoogde stabiliteit van die membraanstrukture en derhalwe
moontlike verhoogde oksidatiewe stabiliteit van braakuikenvleis en -produkte tot gevolg het.
Drie ondersoeke is onderneem by Mariendahl Pluimvee Navorsingstasie te Stellenbosch. Die braakuikens is aangehou in
1 x 0.4 x 0.5m hokke in braaikuikenhuise. In al die proewe is dagoud kuikens gebruik, behalwe eksperiment 1 waar drieweek
oue kuikens gebruik is. Aan die einde van proewe 2 en 3 is die ses-week oue braaikuikens geslag en die karkasse
voorberei vir analise.
Eksperiment 1:
braaikuikens.
Die ware metaboliseerbare energie waarde van Canola voergraadolie (CAO) en Famarol voergraadolie (FAO),
Metaboliseerbare energie van Canola voergraadolie en Famarol voergraadolie vir
gekorregeer vir stikstof retensie (WMEn), is by wyse van proewe op 21 dae oue braaikuikenhaantjies bepaal deur van die
balansrnetode gebruik te maak. Die proewe is tweemaal herhaal vir verhoogde akkuraatheid, met die gebruik van
verskillende monsters van die twee olies vanaf dieselfde bron. Die olies is in twee verhoudings met 'n basale diëet
gemeng om die proef dieet te vorm, nl. 100% Basaal; 96% Basaal: 4% Olie en 92% Basaal: 8% Olie. Die balans proewe
het 3 dae geduur na afloop van 'n aanpassingsperiode van 4 dae. Die WMEn waardes van CAO, bepaal deur middel van
regressie analise, het nie betekenisvol verskil (P>0.05) tussen eksperimente 1 en 2 nie. Die waarde van eksperiment 3
was betekenisvol hoër (P<0.05) as die van die eerste twee eksperimente. Die WMEn waardes van FAO het ook nie
betekenisvol verskil (P>0.05) tussen eksperimente 1 en 2 nie, maar die waarde vir eksperiment 3 was betekenisvol hoër
as dié van eksperiment 1. Die WMEn waardes van COA het betekenisvol verskil (P< 0.05) van dié van FAO vir al die
eksperimente (exp. 1: 30.6 ± 0.399 MJ/kg vir CAO vs. 25.9 ± 0.441 MJ/kg vir FAO; expo 2: 31.0 ± 0.633 MJ/kg vir CAO vs.
26.1 ± 0.668 MJ/kg vir FAO: expo 3: 32.1 ± 0.867 MJ/kg vir CAO vs. 27.1 MJ/kg vir FAO). Eksperiment 2: Die invloed van verskeie rantsoen n-6/n3 vetsuurverhoudings op die produksie en
liggaamsamestelling van braaikuikens.
Die rantsoeneffek van verskeie kombinasies Canola voergraadolie (CAO, 'n hoë vlak van C18:3n-3 en monoonversadigde
vetsure) en Famarol voergraadolie (FAO, 'n hoë vlak van 18:2n-6 en versadigde vetsure) op die
weefselvetsuursamestelling is bestudeer in braaikuikenkarkasse en abdominale vetneerlegging. Die kuikens is van dagoud
to op ses-weke ouderdom een van ses diëte gevoer met die volgende samestellings: 100% FAO, 80% FAO-20%
CAO, 60% FAO - 40%CAO, 40% FAO - 60% CAO, 20% FAO - 80% CAO, 100% CAO. Daar was geen statistiese verskil
tussen die rantsoengroepe (P>0.05) in die gemiddelde daaglikse toename (1.71 ± 0.059 g) of die voeromsetverhoudings
(1.97 ± 0.051) nie. Geen statistiese verskil (P>0.05) is gevind in die chemiese samestelling van die karkasse vir vog
(66.20 ± 0.112 %), proteïn (17.63 ± 0.484 %), lipied (15.92 ± 1.507 %) en as (0.95 ± 0.115 %) inhoud tussen die rantsoen
groepe nie. Geen statistiese verskille (P>0.05) is gevind in die chemiese samestelling van die abdominale vetneerlegging
vir vog (28.77 ± 0.112 %), proteien (3.03 ± 0.484 %), lipied (63.32 ± 9.789 %) en as (0.45 ± 0.135 %) inhoud onder die
rantsoengroepe nie. Met die verhoging in die rantsoen CAO vlakke het die persentasie van C18:2n-6 en C20:4n-6 in die
karkasse verminder met 1.78 % en 0.35 % respektiewelik, terwyl C18:3n-3 en langer ketting n-3 vetsure soos C20:5n-3
en C22:6n-3 respektiewelik met 2.25 %, 0.1 % en 0.67 % verhoog het. Dieselfde tendens is opgemerk in die abdominale
vetneerlegging waar C18:2n-6 en C20:4n-6 afgeneem het met 1.55 % en 0.98 % respektiewelik met die verhoging van
rantsoen CAO, terwyl C18:3n-3, C20:5n-3 en C22:6n-3 verhoog het met 2.13 %, 0.45 % en 0.95 % respektiewelik. Die n-
3/n-6 verhouding in die karkasse en abdominale vetneerlegging het verhoog met 0.16 % en 0.19 % respektiewelik met die
verhoging van die rantsoen CAO. Die resultate toon onomwonde aan dat rantsoen CAO verryk met c-Iinoletensuur,
verlaag versadigde vetsure in braaikuikenkarkasse en -adbdominale vetneerleggings met 4.88 % en 10.63%
respektiewelik, terwyl die mono-onversadigde vetsure met 3.87 % en 7.25 % respektiewelik verhoog word en polionversadigde
vetsure met 1.02 % en 2.38 % respektiewelik verhoog word.
Eksperiment 3: Die invloed van vitamine E op die produksie van braaikuikens en die oksidatiewe stabiliteit,
kleur, mikrobiologiese stabilitiet, vetsuursamestelling en pH van braaikuikenvleis gedurende verkoelde en
bevrore berging.
Eksperiment 1 is uitgevoer met 220 dagoud braaikuikens ten einde die effek van elf konsentrasies van vitamine E (0, 20,
40, 60, 80, 100, 120, 140, 160, 180 en 200 mg a-tokoferyl acetaat / kg voer) op hul produksieprestasie en die oksidatiewe
stabiliteit van hul gevriesde braakuikenkarkasse te evalueer. Die diëte met vitamine E vlakke 0 tot 100 mg is vanaf
dagoud tot 42-dae-ouderdom gevoer, terwyl die diëte met vitamine E vlakke van 120 tot 200mg gevoer is vanaf 21 tot 42-
dae-ouderdom. Die oksidatiewe stabiliteit, soos geëvalueer deur tiobarbituriese suur reaktiewe stowwe (TBARS) waardes,
is bepaal na 30, 90, 120 en 150 dae van berging teen -20°C. Daar was geen statistiese verskille (P>0.05) in die
gemiddelde daaglikse toename (1.85 ± 0.111 g) of voeromsetverhoudings (2.29 ± 0.397) tussen die rantsoengroepe nie.
TBARS waardes het betekenisvol toegeneem (P<0.05) met die verhoging in bergingsperiode, maar het betekenisvol
afgeneem (P<0.05) met verhoogde vitamine E vlakke. Eksperiment 2 is uitgevoer met dagoud braaikuikens ten einde die
effek van vyf konsentrasies van vitamine E (0, 40, 80, 120 and 160 mg a-tokoferyl acetaat / kg voer) op hul prestasie en
die oksidatiewe stabiliteit van hul verkoelde karkasse te evalueer. Die eksperimentele diëte is gevoer vanaf dagoud tot 42-
dae-ouderdom. Die oksidatiewe stabiliteit, geëvalueer deur middel van TBARS waardes, kleur afname en mikrobiologiese
stabiliteit is bepaal na 0, 4, 8, 10 en 12 dae van berging teen 4°C. Vetsuuranalises is gedoen op die monsters van dae 0
en 12. Daar was geen statistiese verskille (P>0.05) in die gemiddelde daaglikse toename (1.88 ± 0.117 g) of
voeromsetverhoudings (2.37 ± 0.467) tussen die rantsoengroepe nie. TBARS waardes het betekenisvol verhoog (P<0.05)
met die verlengde bergingsperiode, maar het betekenisvol afgeneem (P<0.05) met verhoogde viatmine E vlakke. Daar
was geen statistiese verskille (P>0.05) in kleur metings vir L* (44.97 ± 0.662), a* (5.23 ± 0.315) of b* (12.76 ± 0.321)
waardes tussen behandelings nie. Mikrobiologiese tellings het betekenisvol verhoog (P<0.05) oor tyd met die vitamine E konsentrasie wat geen effek getoon het nie. Daar was geen statisties betekenisvolle verskille (P>0.05) vir enige van die
vetsuurgroepe tussen die behandelings nie. Soortgelyks het geen van die vetsure statisties betekenisvolle (P>0.05)
konsentrasieveranderings oor tyd aangetoon nie. Daar was geen statistiese verskil (P>0.05) in die pH (6.01 ± 0.206)
tussen die rantsoengroepe nie.
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The effect of different levels of supplementary feed on the production of finisher ostriches (Struthio camelus) grazing irrigated lucerne (Medicago sativa) pasturesStrydom, Marline 12 1900 (has links)
Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: The purpose of this study was to evaluate the production of slaughter ostriches in a grazing environment at
different levels of supplementary feed.
Two grazing trials were conducted. In the first trial, one group of finisher ostriches (six months old) was put into
a feedlot and received a complete finisher diet. The other four groups were allowed to graze lucerne pasture
(stocking rate of 15 birds/ha) with 1500, 1000, 500, and 0g supplementary feed/bird/day. Pasture production
and intake were measured. There was no difference (P >0.05) between the end mean live weights of the feedlot
ostriches and those two grazing groups receiving 1500 or 1000g supplementation. The average daily gain
(ADG) of the group receiving 1000g supplementation was lower (P <0.05) than the ADG of the group receiving
1500g supplementation, but all three groups reached a mean target slaughter weight of 95kg within the 154 days
of the study. Therefore, pastures together with the correct supplementation (at least 1000g/bird/day) can
replace complete feeds in the finishing phase of slaughter ostriches and can play an important role in the
production of these birds. For lucerne intake, a quadratic relationship (P <0.01) was found between pasture dry
matter (DM) intake (g/bird/day) and supplementary feed intake (g/bird/day). The maximum lucerne intake level
(1692.8g/bird/day) was achieved at 619.6g supplementary feed/bird/day.
In the second grazing trial, finisher ostriches were allowed to graze lucerne pastures at two different stocking
rates (10 and 15 birds/ha) while receiving either 0 or 800g supplementary feed/bird/day. Ostriches receiving
supplementation had higher (P <0.05) mean end live weights than ostriches receiving no supplementation.
Ostriches receiving supplementation reached a mean target slaughter weight of 95kg within the timespan of the
trial, but ostriches receiving no supplementation did not. Stocking rate had no influence on mean end live weight
of the birds. An interaction (P <0.05) was found between the level of supplementation and stocking rate for ADG
of the birds. Stocking rate influenced ADG only for birds receiving no supplementation. As stocking rate
increased, ADG of birds receiving no supplementation declined. Results of the pasture data indicated an
increasing level of replacement of grazed lucerne DM by supplementary feed as the trial progressed and this
was more pronounced at the higher stocking rate of 15 birds per hectare. A high stocking rate seems to have
had a gradual depressing effect on lucerne DM production, while the less severe levels of defoliation at a lower
stocking rate promoted lucerne DM production.
A digestibility trial was conducted with mature ostriches (12 months old) to investigate the effect of
supplementation on intake and digestibility of nutrients, as well as to investigate the substitution effect that
ostriches may display when they receive supplementary feed in addition to grazing. The same dietary
treatments as in the first grazing study were given to ostriches while they were kept in metabolism crates. These
diets were also fed to 20-week old roosters to obtain energy values for these diets for roosters. These energy
values would be used to predict ostrich energy values for the same diets by means of a regression equation. For the roosters, each diet treatment was mixed with 50% maize to prevent digestive disorders and ensure
maximum feed intake. Ostriches started to substitute supplementary feed for pasture when supplementation
was supplied at levels higher than 62% (i.e. 1000g supplementary feed/bird/day) of total feed intake. For each
increase of 100g in supplementary feed intake, pasture was replaced at a rate of 4.9%. Higher (P <0.05) total
feed intakes were reached by ostriches if they grazed lucerne pastures and received supplementation than if
they grazed pasture alone. Pasture grazing alone had lower (P <0.05) dry matter digestibility (DMD) and
apparent metabolizable energy (AME) values for both ostriches and roosters than if pastures were supplied with
a supplement. A significant stepwise regression could not be computed for the prediction of ostrich AME values
from rooster AME values.
The economics of different feeding systems (extensive versus intensive) were evaluated with an economic
analysis, which was based on the same materials and methods and results of the first grazing trial. A margin
above feed cost (MAFC) analysis was performed to evaluate the economic viability of the different feeding
systems. The present value (PV) of the MAFC for the pasture-based system with 1000g/bird/day
supplementation was only 8.3% lower than that of the feedlot system over a period of six years, while the PV of
the cost of the same pasture-based system was 78.4% lower than that of the feedlot system. Birds finished on
lucerne pasture with 1000g supplementation led to a saving of 57% in feeding costs if compared to a feedlot
system. A sensitivity analysis of the MAFC revealed that the pasture-based system was less sensitive to
changes in feeding costs than the feedlot system. Therefore, the unique circumstances of each ostrich producer
will play a role in the decision whether to raise ostriches in a feedlot or on pastures. / AFRIKAANSE OPSOMMING: Die produksie van slagvolstruise in ‘n ekstensiewe weidingsstelsel met verskillende vlakke van aanvullende
voeding is gedurende hierdie studie ge-evalueer.
Twee weidingsstudies is uitgevoer. In die eerste studie is een groep afrondingsvolstruise (ses maande oud) in
‘n voerkraal geplaas en ‘n volledige afrondingsdieet gevoer. Die ander vier groepe is op besproeide
lusernweiding geplaas (teen ‘n weidigtheid van 15 voëls/ha) en het onderskeidelik 1500, 1000, 500 en 0g
aanvullende voeding/voël/dag ontvang. Weidingproduksie en -inname is gemeet. Daar was geen verskil (P
>0.05) tussen die eindgewigte van die voerkraal volstruise en dié van die weidende voëls wat onderskeidelik
1500 en 1000g aanvullende voeding ontvang het nie. Die gemiddelde daaglikse toename (GDT) van die groep
weidende voëls wat 1000g aanvullende voeding ontvang het was laer (P <0.05) as die GDT van die groep
weidende voëls wat 1500g aanvullende voeding ontvang het, maar al drie hierdie groepe het ‘n gemiddelde
teiken slaggewig van 95kg bereik binne die 154 dae van die studie. Weiding, tesame met die korrekte
aanvullende voeding (van ten minste 1000g/voël/dag) kan volvoer rantsoene in die afrondingsfase van
slagvolstruise vervang en kan dus ‘n belangrike rol speel ten opsigte van die produksie van hierdie voëls. Vir
lusern inname is ‘n kwadratiese passing (P <0.01) tussen weiding droë materiaal (DM) inname (g/voël/dag) en
aanvullende voeding inname (g/voël/dag) gevind. Die maksimum lusern inname (1692.8g/voël/dag) is bereik
wanneer voëls 619.6g aanvullende voeding/voël/dag ingeneem het.
In die tweede weidingsstudie, is afrondingsvolstruise (6 maande oud) toegelaat om lusern te bewei teen twee
verskillende weidigthede (10 en 15 voëls/ha) en het ook 0 of 800g aanvullende voeding/voël/dag ontvang.
Volstruise wat aanvullende voeding ontvang het, het hoër (P <0.05) gemiddelde eindgewigte bereik as volstruise
wat geen aanvullende voeding ontvang het nie. Volstruise wat aanvullende voeding ontvang het, het ook die
teiken slaggewig van 95kg bereik binne die tydsduur van die studie, terwyl die volstruise wat geen aanvullende
voeding ontvang het nie, nie daarin kon slag nie. Weidigtheid het nie ‘n invloed (P >0.05) gehad op die
eindgewigte van die voëls nie, maar ‘n interaksie (P <0.05) is gevind tussen vlak van aanvullende voeding en
weidigtheid wat GDT van die voëls betref. Weidigtheid het GDT beïnvloed slegs vir volstruise wat geen
aanvullende voeding ontvang het nie. Soos die weidigtheid van die voëls wat geen aanvullende voeding
ontvang het nie, toegeneem het, het die GDT van hierdie voëls afgeneem. Ontleding van die weidingsdata het
‘n toenemende vlak van verplasing van die weiding met aanvullende voeding getoon soos die studie gevorder
het en dit was meer merkbaar by die hoër weidigtheid. Die hoër weidighteid het ook gelei tot ‘n geleidelike
afname in lusern DM produksie, terwyl die minder aggressiewe vlakke van ontblaring by die laer weidigtheid
lusern DM produksie bevorder het.
‘n Verteringsstudie is gedoen met volwasse volstruise (12 maande oud) om die invloed van aanvullende voeding
op inname en verteerbaarheid van nutriente te toets, asook om die substitusie effek wat volstruise mag toon wanneer hulle aanvullende voeding ontvang op weiding, te ondersoek. Dieselfde dieet behandelings as in die
eerste weidingsstudie is vir die volstruise gegee terwyl hulle in metabolisme kratte aangehou is. Hierdie diëte is
ook aan 20-week oue hane gevoer om die energie waardes van die diete vir hane te verkry. Hierdie
energiewaardes sal dan gebruik word om volstruis energiewaardes te voorspel vir dieselfde diëte met behulp
van ‘n regressie vergelyking. Vir die hane is elke dieet gemeng met 50% mielies om inname te handhaaf en
spysverteringsstoornisse te voorkom. Volstruise het weiding begin verplaas met aanvullende voeding sodra die
vlak van aanvullende voeding hoër as 62% (d.i. meer as 1000g aanvullende voeding/voël/dag) van die totale
inname van die voëls was. Vir elke 100g toename in aanvullende voeding, word weiding verplaas teen ‘n tempo
van 4.9%. Weiding, tesame met aanvullende voeding, het gelei tot hoër totale droë material (DM) voerinnames
by volstruise as wanneer weiding alleen beskikbaar was. Wanneer weiding alleen voorsien was, was daar laer
(P <0.05) verteerbaarhede van DM en waarskynlike metaboliseerbare energie (WME) waardes vir beide
volstruise en hane as wanneer die weiding voorsien word met aanvullende voeding. Geen betekenisvolle
stapsgewyse regressie kon gevind word om volstruis energie waardes uit hoender energie waardes te voorspel
nie.
Die ekonomie van verskillende sisteme (ekstensief versus intensief) is in hierdie studie vergelyk en is gebaseer
op dieselfde materiaal en metodes en resultate van die eerste weidingsstudie. ‘n Marge bo voerkoste analise is
gebruik om die ekonomiese lewensvatbaarheid van die sisteme met mekaar te vergelyk. Die huidige waarde
van die marge bo voerkoste van die weidingssisteem waar 1000g aanvullende voeding gevoer word was 8.3%
laer as dié van die voerkraal sisteem oor ‘n periode van ses jaar. Daarteenoor was die huidige waarde van die
koste van dieselfde weidingssisteem 78.4% laer as dié van die voerkraal sisteem. Die weidingssisteem waar
volstruise 1000g aanvullende voeding ontvang het, het ‘n besparing van 57% in voerkoste getoon wanneer dit
met die voerkraal volstruise vergelyk is. ‘n Sensitiwiteitsanalise van die marge bo voerkoste het getoon dat die
weidingssisteem minder sensitief is vir wisselende voerkoste as die voerkraal sisteem. Die unieke
omstandighede van elke produsent sal ‘n rol speel in sy keuse om volstruise op weiding of in ‘n voerkraal af te
rond.
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Oat silage in milk production systems in the Western CapeBangani, N. M. (Noluvuyo Muriel) 03 1900 (has links)
Thesis (MScAgric)--Stellenbosch University, 2002. / ENGLISH ABSTRACT: The objectives of this study were to determine the effects of supplementing oat silage
(OS) with lucerne (LH) and oat hay (OH) on the production performance of lactating
Jersey cows, as well as comparing the ruminal degradability of LH, OH and OS III
Holstein and Jersey cows receiving a high forage diet and a high concentrate diet.
In the first trial, five diets containing different combinations of OS and LH together with
concentrate mixtures providing 26, 23, 20, 17 and 14% crude protein (CP) were fed to
lactating Jersey cows. Lucerne hay was fed at 0, 2, 4, 6, and 8 kg DM/day while OS was
fed ad libitum. Cows receiving only OS as a forage source had a lower (P<0.05) dry
matter (DM) intake and produced less milk protein (P<0.05). Milk and fat yields as well
as milk urea nitrogen (MUN) levels did not differ (P>0.05) between treatments.
In the second trial, OS was fed with OH and a concentrate mixture containing 26% CP to
lactating Jersey cows. Oat hay was fed at 0, 2, 4, 6, and 8 kg DMiday while OS was fed
ad libitum. Cows that received OS together with 4 and 6kg OH, respectively had higher
(P<0.05) DM intakes. Milk, fat, and protein yields as well as MUN levels did not differ (P>O.05) between treatments.
The ruminal degradability of LH, OH and OS in Holstein and Jersey cows receiving (i) a
high forage and (ii) a high concentrate diet was determined. The two breeds were also
compared in terms of rumen pH levels, volatile fatty acids (VF A) and rumen ammonia
nitrogen (NH3-N) concentrations as affected by time after feeding. The ruminal
degradability of freeze dried (FD), oven dried (OD) and fresh oat silage (FS) in Jersey
cows receiving a high forage diet was also determined.
The ruminal DM, CP and NDF degradability of LH was higher (P<O.05) than that of OH
and OS in both Holstein and Jersey cows when they were fed either a high forage or a
high concentrate diet. When cows were fed a high forage diet, the effective DM
degradability of OS was higher (P<O.05) in Holsteins although the CP degradation rates
of LH and OH were higher (P<O.05) in Jerseys. When they were fed a high concentrate
diet, Jerseys had higher (P<O.05) effective DM and NDF degradabilities and higher
(P<O.05) DM and NDF degradation rates in LH while Holsteins had higher (P<O.05)
effective CP degradability levels than Jerseys in OS.
After feeding a high forage diet, pH levels declined while VFA and NH3-N
concentrations increased (P<O.05) in both breeds. Jerseys had higher rumen pH, lower
(P<O.05) VFA and lower NH3-N concentrations than Holsteins throughout the study.
When cows were fed a high concentrate diet, Jerseys had higher (P<O.05) pH than
Holsteins. A post-feeding decline (P<O.05) in pH was observed in both breeds.
Fresh oat silage had a lower (P<O.05) effective degradability and degradation rates for
DM, CP and NDF in comparison to FD and OD oat silage. The DM, CP and NDF
degradation rates, as well as effective NDF degradability were higher (P<O.05) for FD
silage, but effective DM and CP degradabilities were higher (P<O.05) for OD oat silage.
It was concluded that on an oat silage diet, lactating Jersey cows should receive a
minimum of 2kg LH or 4 to 6kg oat hay together with ad libitum OS to improve DM intake. When cows were fed a high concentrate diet, the ruminal degradability appeared
to be superior in Jerseys than Holsteins. Jerseys also had higher rumen pH levels lower
VFA and NH3-N concentrations than Holsteins. Feeding interval affects the rumen
environment, pH declines while VF A and NH3-N concentrations increased. / AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om die effek van die aanvulling van hawerkuilvoer met
lusemhooi (LH) en hawerhooi (HH) op die melkproduksie van Jerseykoeie te bepaal.
Hiermee saam is die rumen degradeerbaarheid van hawerkuilvoer en lusemhooi
ondersoek in Jersey en Holsteinkoeie wat 'n hoe-ruvoer en 'n hoe-kragvoer gebaseerde
dieet ontvang het.
In die eerste proef is vyf diete met verskillende peile van hawerkuilvoer en lusernhooi
saam met kragvoere van verskillende ruproteienpeile (26, 23, 20, 17 en 14% RP) aan 10
lakterende Jerseykoeie gevoer. Hawerkuilvoer is ad libitum voorsien en lusemhooi is
teen vlakke van 0, 2, 4,6 en Skg droemateriaal (DM) per dag gevoer. Die DM-inname en
melkproteienproduksie van koeie wat hawerkuilvoer as die enigste ruvoerbron ontvang
het, was laer (P<0.05) as ander ruvoerkombinasies. Die melk- en vetproduksie, asook
melk-ureumstikstofpeile het nie tussen behandelings verskil nie (P>0.05).
In die tweede proef is hawerkuilvoer saam met hawerhooi (soortgelyk as Proef 1) gevoer.
Die kragvoerkomponent van al die ruvoerkombinasies het 26% RP bevat. Die koeie wat
hawerkuilvoer en 4 of 6kg hawerhooi as ruvoere ontvang het, het hoer (P<O.05)
droemateriaalinnames gehad. Melk, vet en proteienproduksie asook melk-ureumstikstofpeile
het nie tussen ruvoerkombinasies verskil nie (P>O.05).
Die rumendegradeerbaarheid van lusemhooi, hawerhooi en hawerkuilvoer is bepaal in
Holstein en Jerseykoeie wat (i) 'n hoe ruvoer- en (ii) 'n hoe kragvoerdieet ontvang het.
Die rumen pH, vlugtige vetsuur en rumen-ammoniakkonsentrasies, soos beinvloed deur
tyd na voeding, is ook tussen rasse vergelyk. Die rumendegradeerbaarheid van vars,
oondgedroogde en vriesgedroogde hawerkuilvoer is ook bepaal.
Die rumen DM, RP en NDF degradeerbaarhede van lusemhooi was hoer (P<O.05) as by
hawerhooi en hawerkuilvoer in beide Holstein en Jerseykoeie wat (i) 'n hoe ruvoer- en
(ii) 'n hoe kragvoerdieet ontvang het. Op 'n hoe ruvoerdieet, was effektiewe DM
degradeerbaarheid van hawerkuilvoer by Holsteins hoer (P<O.05) as by Jerseys.
Jerseykoeie het egter 'n hoer (P<O.05) RP degradeerbaarheidstempo van lusemhooi en
hawerhooi gehad.
Jerseykoeie op 'n hoe kragvoerdieet, het hoer (P<O.05) effektiewe DM en NDF
degradeerbaarhede getoon. Hulle het egter 'n laer (P<O.05) effektiewe ruprotein (RP)
degradeerbaarheid by hawerkuilvoer as Friese gehad. Jerseykoeie op lusemhooi het ook
'n hoer (P<O.05) DM en NDF degradeerbaarheidstempo getoon.
Jerseykoeie wat 'n hoe ruvoerdieet ontvang het, het 'n hoer (P<O.05) rumen- pH en laer
(P<O.05) vlugtige vetsuur- en rumen-ammoniak konsentrasies as Holsteinkoeie gehad.
Jerseykoeie wat 'n hoe kragvoerdieet ontvang het, het ook 'n hoer (P<O.05) rumen- pH as
Holsteinkoeie gehad. By al die koeie is gevind dat rumen- pH na voeding afgeneem het
(P<O.05). Vlugtige vetsuur- en rumen-ammoniakkonsentrasies was laag voor voeding en
het daama toegeneem (P<O.05).
Vars hawerkuilvoer het laer (P<O.05) effektiewe DM, RP en NDF degradeerbaarhede en
degradeerbaarheidstempo's as oond- en vriesgedroogde hawerkuilvoer gehad. Die
vriesgedroogde kuilvoer het hoer (P<O.05) DM, RP en NDF degradeerbaarheidstempo's
sowel as effektiewe NDF degradeerbaarhede gehad. Oondgedroogde kuilvoer het
daarinteen hoer (P<O.05) effektiewe DM en RP degradeerbaarhede gehad.
Die gevolgtrekking is gemaak dat lakterende Jerseykoeie ten minste 2kg lusemhooi of 4-
6kg hawerhooi per dag moet ontvang wanneer hulle hawerkuilvoer as ruvoerbron
ontvang. Op 'n hoe kragvoerdieet, het dit gebleik dat die rumendegradeerbaarheid van
vesel by Jerseys beter is as by Holsteins. Die rumen- pH is hoog voor voeding, maar dit
neem af nadat die koeie gevreet het. Die rumen- pH van Jerseys was hoer as by
Holsteins. Die vlugtige vetsure en rumen-ammoniakkonsentrasies blyk laag te wees voor
voeding en neem daama toe. Konsentrasies was hoer by Holstein as by Jerseys.
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The use of fibrolytic enzymes in maize-soya based broiler dietsBotha, Corne J. 03 1900 (has links)
Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2011. / Includes bibliography. / ENGLISH ABSTRACT: A growth and digestibility trial was conducted comparing the effect of an experimental enzyme at
three different inclusions. A negative control containing no enzyme additions and a positive control
containing a proven commercial enzyme were compared in a maize-soybean diet noting the
performance of broilers and the digestibility of the grower feed. The commercial enzyme was a
granular product with a xylanase activity of 38114.29 nkat/g and the second enzyme (ABO374) was a
liquid experimental product with a xylanase activity of 1426.86 nkat/ml. Five diets were used i.e.
control basal diet without enzyme supplementation (negative control), basal diet supplemented with
the commercial enzyme (positive control) and three basal diets supplemented with the test enzyme at
various inclusion levels (ABO 50, ABO 100 and ABO 200). The positive control was supplemented
with 200 g/ton of the commercial enzyme; ABO 50 was supplemented with ABO374 at an inclusion
level of 2671 ml/ton, ABO 100 with 5342 ml/ton and ABO 200 with 10684 ml/ton. Supplementation
with the test enzyme (ABO 50) significantly improved BW at 23 days of age by 4.6 % (1107.4 g vs
960.96 g) and at 37 days of age by 3.2 % (2311.75 g vs 2237.81 g) over the negative control. Body
weight gain for the total period of the trial was significantly improved by 3.24 % (64.32 g/bird/day vs
62.24 g/bird/day) the test enzyme supplementation (ABO 50) when compared to the negative control.
During the starter phase, test enzyme supplementation (ABO 50) led to an improvement of 4.58 %
(1.25 vs 1.31) in FCR in comparison with the negative control. The FCR for the total trial obtained by
the test enzyme supplementation was significantly lower than the FCR obtained by the positive
control. The highest EPER obtained for this trail was by the test enzyme supplemented diets and this
was significantly higher than the EPER obtained by the positive control. It is clear from this growth trial
that the test enzyme (ABO374) at an inclusion level of 2671 ml/ton outperformed the commercial
enzyme and that it has the potential to improve the production performance of broilers on a maizeSBM based diet.
The total tract digestibility method and total collection method was used to conduct the digestibility
trial. The total tract digestibility method measures the difference between the amounts of each nutrient
consumed from the amounts of each nutrient excreted in faeces. Only apparent digestibilities are
reported for the digestibility trial. Apparent digestibility does not take the endogenous protein fraction
in the faeces into account. The endogenous protein fraction is derived from digestive enzymes and
proteins from the intestinal walls that are secreted into the digestive tract. The grower negative
control, positive control, ABO 50, ABO 100 and ABO 200 diets used in the production trial were also
used in the digestibility trial. Supplementation with the test enzyme showed no significant
improvements on the apparent digestibility of dry matter, organic material, ash, crude protein,
metabolisable energy or crude fibre. No significant improvements in the apparent digestibility of the
amino acids (threonine, arginine, valine, lysine, methionine, cysteine and isoleucine) were noticed either and thus the digestibility of the grower feed were not influenced by the addition of enzymes due
to the supplementation of the test enzyme ABO374.
Pelletisation of the grower diets could have lead to the inactivation of the enzyme due to the high
temperature at which pelletisation takes place. Another possible reason why enzyme supplementation
did not increase nutrient digestibility, may be that the breakdown of non-starch polysaccharides by the
enzymes led to an increase in the concentration of oligosaccharides in the small intestine of the birds,
thus leading to the decrease in nutrient absorption
Key words: body weight, body weight gain, feed conversion ratio, European production efficiency
ratio, maize, soybean meal, apparent digestibility, dry matter, organic material, ash, crude protein,
metabolisable energy, crude fibre, xylanase, pellitisation. / AFRIKAANSE OPSOMMING: ‘n Groei en vertering studie was uitgevoer om die effek van ‘n eksperimentele ensiem wat teen drie
verskillende insluitingsvlakke by ‘n basale dieët bygevoeg is te vergelyk met ‘n negatiewe kontrole wat
geen ensiem bevat het nie en met ‘n positiewe kontrole wat ‘n kommersiële ensiem bevat in ‘n mielesojaboon oliekoek dieët op die produksie vermoë van braaikuikens en die verteerbaarheid van die
groei voer. Die kommersiële ensiem was ‘n granulêre produk met ‘n xylanase aktiwiteit van 38114.29
nkat/g en die eksperimentele ensiem (ABO374) was ‘n vloeistof produk met ‘n xylanase aktiwiteit van
1426.86 nkat/ml. Vyf diëte was gebruik nl. ‘n basale dieët met geen ensiem byvoeging (negatiewe
kontrole), basale dieët met die byvoeging van die kommersiële ensiem (positiewe kontrole) en drie
basale diëte wat met die byvoeging van die eksperimentele ensiem teen drie verskillende insluitings
vlakke (ABO 50, ABO 100 and ABO 200). Die kommersiële ensiem was by die positiewe kontrole
bygevoeg met ‘n insluitings vlak van 200 g/ton, ABO374 was bygevoeg by ABO 50 met ‘n insluitings
vlak van 2671 ml/ton, ABO 100 met 5342 ml/ton en ABO 200 met 10684 ml/ton. Die byvoeging van
die eksperimentele ensiem (ABO 50) het gelei tot die betekenisvolle verbetering van die
liggaamsmassa van die voëls by die ouderdom van 23 dae met 4.6 % (1107.4 g teenoor 960.96 g) en
by die ouderdom van 37 dae met 3.2 % (2311.75 g teenoor 2237.81 g) teenoor die negatiewe
kontrole. Liggaams massa toename vir die hele periode van die studie was betekenisvol verhoog met
3.24 % (64.32 g/kuiken/dag teenoor 62.24 g/kuilen/dag) met die byvoeging van die eksperimentele
ensiem (ABO374) teenoor die negatiewe kontrole. Voeromset verhouding was betekenisvol verbeter
met 4.58 % (1.25 teenoor 1.31) toe die kommersiële ensiem bygevoeg was teenoor die negatiewe
kontrole. Die hoogste europese produksie effektiwiteits verhouding wat verkry is vir die hele studie
periode is deur die byvoeging van die eksperimentele ensiem (ABO374). Hierdie groei studie dui dus
duidelik aan dat die gebruik van die eksperimentele ensiem (ABO374) baie beter resultate as die
kommersiële ensiem opgelewer het teen ‘n insluitings vlak van 2671 ml/ton, dus het ABO374 die
potensiaal om die produksie potensiaal van braaikuikens op ‘n mielie-sojaboonoliekoek dieët te
verbeter.
Die totale spysverteringskanaal verteerbaarheid metode was gebruik om die verteerbaarheid studie
uit te voer. Die totale spysverteringskanaal verteerbaarheid metode meet die verskil tussen die
nutriënt inhoud van die voer en die nutriënt inhoud van die mis. Slegs die skynbare verteerbaarheid
van nutriënte word vir hierdie verteerbaarheidstudie gerapporteer. Skynbare verteerbaarheid sluit nie
die endogene proteïenfraksie wat afkomstig is van verteringsensieme of die proteïene afkomstig
vanaf die spysverteringskanaal se intestinale wande af in nie. Die negatiewe kontrole, positiewe
kontrole, ABO 50, ABO 100 en ABO 200 groei diëte gebruik in die produksie studie is gebruik vir die
verteringsstudie. Die byvoeging van die eksperimentele ensiem het geen betekenisvolle resultate
opgelewer ten opsigte van droë materiaal, organiese material, as, ru-proteïen, ru-vesel of
metaboliseerbare energie nie. Daar was ook geen betekenisvolle resultate opgelewer wanneer die
eksperimentele ensiem bygevoeg was nie ten opsigte van die verteerbaarheid vir aminosure
(treonien, arginien, valien, metionien, sisteïen en isoleosien) nie en dus is die verteerbaarheid van die
groeivoer glad nie beïnvloed deur die byvoeging van die eksperimentele ensiem nie. Die verpilling van die groei voer mag dalk gelei het tot die inaktivering van die eksperimentele ensiem
deur dat dit blootgestel was aan hoë temperature. ‘n Ander moontlike rede vir die mislukking van die
ensiem kon gewees het dat die afbreking van die nie-stysel polisakkariedes deur die ensiem kon gelei
het tot die verhoging van die oligosakkariede konsentrasie in die laer spysverterings kanaal en dus
kon dit lei tot ‘n verhoogde deurvloeitempo, gevolg deur ‘n afname in die absorpsie van nutriënte.
Sleutel woorde: Liggaamsmassa, liggaamsmassa toename, voeromsetverhouding Europese
produksie effektiwiteits verhouding, mielie, sojaboonoliekoek, skynbare verteerbaarheid, droëmaterial,
organiesematerial, as, ru-proteïen, ru-vesel, metaboliseerbare energie, verpilling.
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Substitution of maize with high fibre by-products in concentrates supplemented to dairy cows grazing kikuyu/ryegrass pasture during springLingnau, Werner August Leonhard 03 1900 (has links)
Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: Kikuyu over-sown with ryegrass forms the basis of pasture based systems in the Southern Cape. During
early spring, energy is the first limiting nutrient in kikuyu/ryegrass pasture, supplementation is thus
essential. Supplementation consists mainly of high starch concentrates (high maize inclusion), which is
expensive and could negatively affect rumen parameters. The objective of this study was to determine if
milk production could be improved or maintained, and if the rumen environment would be improved, by
replacing high starch concentrates with low starch (high by-product) concentrates for dairy cows on
kikuyu/ryegrass pasture.
Forty-five multiparous, high producing, lactating Jersey cows [body weight, 340 ± 34.7 kg; milk yield (MY),
19.6 ± 2.23kg/d; days in milk (DIM), 153 ± 33.5; lactation number, 3.6 ± 1.85; (mean ± SD)] were used in
the production study. A randomised block design was used. The forty-five cows were allocated to fifteen
groups of three each (blocking) on the basis of MY, DIM, and lactation number. Cows from each group
were randomly allocated to one of three treatment groups (high starch, medium starch and low starch
concentrate supplementation). Cows were fed 6kg (3kg during each milking) concentrate per day and
were allocated fresh pasture ad lib after each milking. There were no significant differences (P > 0.05)
found in milk yield and fat corrected milk yield between treatment groups. Milk fat percentage was
significantly higher (P < 0.05) in the low starch treatment than in the high starch treatment. Milk fat yield
was significantly higher (P < 0.05) in both the low starch and the medium starch treatment when
compared to the high starch treatment. Milk protein and lactose percentages, as well as milk urea
nitrogen and somatic cell count, did not differ significantly (P > 0.05) between treatments. Live weight
change, as well as body condition score change, was unaffected (P > 0.05) by treatments indicating body
reserves were not used to maintain milk production in the low starch treatment. A rumen metabolism study was also done with ten lactating, cannulated Jersey cows [body weight, 332 ±
56.3 kg; MY, 17.3 ± 1.73kg/d (mean ± SD)] were used. The cows were divided into two groups of five
each, on the basis of lactation number, DIM, and MY. The five cows from each group were randomly
allocated to one of two treatment groups (high starch and low starch concentrate supplementation) and
used in a cross-over design. Cows were fed 6kg concentrate per day and were allocated fresh pasture ad
lib after each milking. The volatile fatty acid (VFA) concentration was significantly higher (P < 0.05) in the
high starch treatment when compared to the low starch treatment. The individual VFA’s, acetic-,
propionic- and butyric acid concentrations were also significantly higher (P < 0.05) in the high starch
treatments when compared to the low starch treatment. The acetic to propionic acid ratio was unaffected
(P > 0.05) by treatment. Rumen ammonia-nitrogen concentration was significantly higher (P < 0.05) in the
high starch treatment. Rumen pH was unaffected (P > 0.05) by supplementation type. The in sacco dry
matter and neutral detergent fibre digestibilities of the kikuyu/ryegrass pasture were unaffected (P > 0.05)
by treatment type.
Results indicated that milk production could be maintained with low starch concentrates which also
improved milk composition. Results further suggested that the rumen environment was relatively
unaffected by low starch concentrate supplementation. / AFRIKAANSE OPSOMMING: Kikoejoe, oorgesaai met raaigras, vorm die basis van weidingstelsels in the Suid-Kaap. Tydens die
lentemaande is energie die eerste beperkende voedingstof op kikoejoe/raaigras weidings, wat
kragvoeraanvulling noodsaaklik maak. Aanvulling bestaan grootliks uit hoëstysel-kragvoer (hoë mielieinhoud)
wat nie net duur is nie, maar dit kan ook die rumenomgewing benadeel. Die doel van die studie
was om vas te stel of melkproduksievlakke onderhou kan word en of rumenomgewing verbeter kan word
deur die vervanging van hoëstysel-kragvoer met laestysel-kragvoer (hoë neweprodukinhoud) vir
melkkoeie op kikoejoe/raaigras weidingstelsels.
Vyf-en-veertig meervoudige pariteit-, hoë produserende, lakterende Jerseykoeie [liggaamsmassa, 340 ±
34.7 kg; melkproduksie, 19.6 ± 2.23kg/d; dae in melk, 153 ± 33.5; laktasienommer, 3.6 ± 1.85; (gem ±
standaardafwyking)] is gebruik vir die produksiestudie van die proef. Daar is gebruik gemaak van ‘n
ewekansige blokontwerp. Die vyf-en-veertig koeie is opgedeel in vyftien groepe van drie elk, gebaseer op
melkproduksie, dae in melk en laktasienommer. Koeie in elke groep is ewekansig aan een van drie
behandelings (hoëstysel-, mediumstysel- of laestysel-kragvoeraanvulling) geallokeer. Koeie is daagliks
6kg (3kg tydens twee milkings) kragvoer gevoer en vars weiding was ad lib beskikbaar na elke melking.
Daar was geen beduidende verskil (P > 0.05) in melkopbrengs of vet-gekorrigeerde melkopbrengs tussen
die drie behandelings nie. Bottervetpersentasie was beduidend hoër (P < 0.05) in die
laestyselbehandeling in vergelyking met die hoëstyselbehandeling. Bottervetopbrengs was beduidend
hoër (P < 0.05) in beide die laestysel- en mediumstyselbehandelings in vergelyking met die
hoëstyselbehandeling. Melkproteïen- en melklaktosepersentasies, asook melkureumstikstof en somatise
seltelling, was onveranderd (P > 0.05) tussen behandelinge. Liggaamsmassa en liggaamskondisietelling
het geen verskille (P > 0.05) getoon tussen behandelings nie, wat daarop dui dat liggaamsreserwes nie
gebruik is om melkproduksie in die laestyselbehandeling te onderhou nie. ‘n Rumenmetabolismestudie is ook uitgevoer met tien lakterende, gekannuleerde Jerseykoeie
[liggaamsmassa, 332 ± 56.3 kg; melkproduksie, 17.3 ± 1.73kg/d (gem ± standard afwyking)]. Die koeie is
in twee groepe van vyf elk verdeel, gebasseer op laktasienommer, dae in melk en melkproduksie. Die vyf
koeie van elke groep is in ‘n omslagontwerp gebruik en is ewekansig aan een van twee behandelings
(hoëstysel- of laestysel-kragvoeraanvulling) geallokeer. Koeie het daagliks 6kg kragvoer ontvang en vars
weiding was ad lib beskikbaar na elke melking. Die vlugtige vetsuurkonsentrasie was beduidend hoër (P
< 0.05) in die hoëstyselbehandeling as in die laestyselbehandeling. Die individuele vlugtige vetsure
naamlik asynsuur, propionsuur en bottersuur, was ook beduidend hoër (P < 0.05) in die
hoëstyselbehandeling as in die laestyselbehandeling. Die asynsuur- tot propionsuurverhoudings het geen
verskille (P > 0.05) tussen behandelings getoon nie. Rumen-ammoniakstikstof was beduidend hoër (P <
0.05) in die hoëstyselbehandeling as in die laestyselbehandeling. Rumen-pH het geen verskille (P > 0.05)
getoon tussen behandelings nie. Die in sacco droëmateriaal- en neutraalbestande veselverteerbaarhede
van kikoejoe/raaigras weiding het geen verskille (P > 0.05) tussen behandelings getoon nie.
Die resultate het aangedui dat melkproduksie onderhou kan word en dat melksamestelling verbeter kan
word met laestysel-kragvoeraanvulling. Resultate het ook daarop gedui dat die rumenomgewing nie
noodwendig verbeter word deur die aanvulling van laestysel-kragvoer vir koeie op kikoejoe/raaigras
weidings nie.
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The effect of fine particle removal from ground forage samples on In Saccro dry matter and neutral detergent fiber disappearance valuesMack, Claudia Isabell 03 1900 (has links)
Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: In vitro and in situ methods using the in sacco technique have a wide application in ruminant
nutrition as they allow the degradability and quality of forages and ruminant diets to be
determined quicker and at a lower cost than in vivo methods. These trials make use of artificial
fibre bags, made of polyester (dacron) or nylon which are available in variable pore sizes.
Results from such degradability trials are of great value to feed formulation programs such as
AMTS.cattle and CPM Dairy and the more accurate the results are obtained from such trials the
more accurate feed formulation models are enabling the ruminant nutritionist to formulate the
best diet possible to reach the genetic potential of ruminants. The accepted method for in sacco
trials (NRC, 2001) requires that the feed samples are ground through a 2 mm screen. This
usually results in a variety of particle sizes, including a significant amount of extremely fine
particles. Research has, however, shown that these fine particles can potentially be washed out
of the dacron bags that are used in in sacco degradability trials. This would result in an overestimation
of the soluble and rapidly fermentable nutrient fractions. The objective of this study
was to determine the effect of fine particle removal from ground forage samples on the chemical
composition and in vitro dry matter (DM) and neutral detergent fibre (NDF) degradability of
forages. Lucerne hay, oat hay and wheat straw samples were sourced from seven different
locations in the Western Cape. Samples were milled through a 2 mm screen and then sieved
through either 150 μm, 125 μm or 106 μm. All fractions were analysed for DM, crude protein
(CP), NDF, fat and ash. Based on the NDF content of the original samples, four samples from
each forage type were selected for in vitro trials to determine DM and NDF disappearance over
time. Samples were incubated for 0, 6, 24 and 48 hours in an ANKOM Daisy II incubator.
Significant variation occurred within forage types in terms of chemical composition. Fine particle removal had no effect on the NDF content of lucerne hay and wheat straw, but sieved oat hay
fractions had a higher NDF content than the un-sieved samples. The NDF content was on
average 635.9 for the sieved OH fractions, whereas the NDF content of the un-sieved samples
was 606.8. The CP content of sieved oat hay (61.4 on average) and wheat straw fractions (47.7
on average) were lower than the un-sieved fractions (65.7 for OH and 55.4 for WS), whereas for
lucerne hay, sieving had no effect on CP content.
Dry matter and NDF disappearances were significantly higher for the un-sieved samples than
for the sieved fractions for all three forage types at all incubation times, which indicates an overestimation
of the soluble and readily digestible forage fractions. Compared to sieved samples,
DMD values at 0 hours (washing only) of the un-sieved samples were, on average, 13.8%
higher for lucerne hay, 27.3% for oat hay and 44.7% for wheat straw. At 48 h, the overestimation
of lucerne DMD for the un-sieved samples was between 4.0% (compared to 106 μm
sieve) and 7.3% (compared to 150 μm sieve). This over-estimation in the un-sieved samples
was carried over to all four time points. No significant differences between the fractions (150,
125 and 106) were found within a forage type at all incubation times. The estimated degradation
rates and the predicted digested proportions were also significantly higher for the un-sieved
fractions compared to the sieved fractions. It was concluded that fine particle removal from
forage samples would result in more accurate estimations of in sacco nutrient degradability. / AFRIKAANSE OPSOMMING: In sacco in vitro- en in situ-metodes word dikwels toegepas in die studie van herkouervoeding
aangesien hierdie metodes vinniger, meer effektief en meer ekonomies is as in vivo-metodes.
Hierdie studies maak gebruik van kunsveselsakkies, gemaak van poliëster (dacron) of nylon wat
beskikbaar is in verskeie poriegroottes. Resultate van sulke verteringsproewe is belangrik vir
toepassing in voerformuleringsprogramme soos AMTS.cattle en CPM Dairy. Die resultate wat
deur hierdie studies verkry word, is belangrik vir akkurate voerformulering deur formuleringsmodelle
en stel die herkouervoedingkundige in staat om die ideale voer te formuleer vir die
manifestering van die dier se genetiese potensieaal. Die aanvaarde in sacco-metode (NRC,
2001) vereis dat voermonsters deur ‘n 2 mm sif gemaal word wat ‘n groot verskeidenheid
partikelgroottes tot gevolg het met ‘n beduidende hoeveelheid baie fyn materiaal. Navorsing het
getoon dat hierdie baie fyn partikels uit die dacronsakkies gewas kan word tydens in sacco
verteringstudies, met die gevolg dat die oplosbare en vinnig-verteerbare fraksie oorskat kan
word. Die doel van die huidige studie was om die invloed van die verwydering van fyn partikels
op die chemiese samestelling van ruvoermonsters te bepaal, asook die in vitro droë materiaal
(DM) en neutraal-onoplosbaare vesel (NDF) verteerbaarheid daarvan. Monsters van lusernhooi,
hawerhooi en koringstrooi, afkomstig van sewe verskillende lokaliteite in die Wes-Kaap, is deur
'n 2 mm sif gemaal en sub-monsters is deur ‘n reeks siwwe met poriegroottes van 150 μm, 125
μm of 106 μm gesif. Al die fraksies is geanaliseer vir DM, ruproteïen (RP), NDF, vet en as. Vier
monsters van elke voertipe is op grond van die NDF-inhoud geselekteer vir in vitro-studies om
die DM- en NDF- verteerbaarheid oor tyd te bepaal. Monsters is vir 0, 6, 24 of 48 uur
geïnkubeer. Die resultate het getoon dat daar betekenisvolle variasie in chemiese samestelling
binne ruvoertipes voorgekom het. Die verwydering van die fyn partikels het geen invloed die NDF-inhoud van lusernhooi en koringstrooi gehad nie. Wat hawerhooi betref, was die NDFinhoud
van die gesifte monsters egter betekenisvol hoër in vergelyking met die ongesifte
monsters. Die NDF inhoud was gemiddeld 635.9 vir die gesifte monsters en vir die ongesifte
monsters 606.8. Sifting het geen invloed op die RP-inhoud van lusernhooi gehad nie, maar vir
hawerhooi (61.4 gemiddeld) en koringstrooi (47.7 gemiddeld) was die RP-inhoud van die gesifte
monsters betekenisvol laer as dié van die ongesifte monsters (65.7 vir hawerhooi en 55.4 vir
koringstrooi).
In vergelyking met die gesifte monsters, was die in vitro DM- en NDF-verteerbaarhede
betekenisvol hoër vir die ongesifte monsters vir al drie ruvoertipes by alle inkubasietye. Hierdie
resultate bevestig ‘n oorskatting van oplosbare en maklik verteerbare fraksies in gemaalde
voermonsters. In vergelyking met die gesifte monsters, was die DMV-waardes van die ongesifte
monsters by 0 ure (slegs gewas) gemiddeld 13.8% hoër vir lusernhooi, 27.3% vir hawerhooi en
44.7% vir koringstrooi. Na 48 h inkubasie was die oorskatting van lusern DMV vir die ongesifte
monsters tussen 4.0% (vergeleke met die 106 μm sif) en 7.3% (vergeleke met 150 μm sif). Die
oorskatting is oorgedra na al vier inkubasietye. Die resultate het geen noemenswaardige
verskille tussen die fraksies (150 μm, 125 μm en 106 μm poriegroottes) van ‘n ruvoertipe by
enige inkubasietyd aangedui nie. Die beraamde verteringstempo’s en verteerde fraksies was
ook aansienlik hoër vir die ongesifte monsters in vergelyking met die gesifte monsters. Die
gevolgtrekking is gemaak dat die verwydering van fyn partikels uit gemaalde ruvoermonsters
die akkurate bepaling van in sacco verteerbaarheidswaardes verhoog.
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Distribution and stability of soil carbon in spekboom thicket, Eastern Cape, South AfricaMchunu, Sinethemba Euginia 03 1900 (has links)
Thesis (MScAgric)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Soils of semi-arid regions generally have low organic matter contents, primarily attributed to prevailing climatic conditions. Yet, the spekboom thicket, located in the semi-arid region of the Eastern Cape (South Africa) has been distinguished to accumulate large amounts of soil carbon. To further understand this remarkable accumulation, a detailed investigation was carried out to evaluate the distribution, speciation and stability of the soil carbon from directly beneath spekboom (Portulacaria afra) and other “nonspekboom” vegetation within the intact thicket, and from adjacent, degraded (overgrazed), open thicket sites.
In the first experimental chapter, the distribution of organic and inorganic C, as well as general soil properties (pH, EC, exchangeable and water soluble cations, hydrophobicity, water stable aggregates) were investigated in the intact (spekboom and nonspekboom) and degraded (open) thicket soils. There were no significant differences in the C content (organic or inorganic) between the spekboom and nonspekboom sites in the intact thicket. Soil organic carbon (SOC) content however was greatly influenced by thicket degradation, whereas, inorganic C remained unaffected. Mean organic C (0-50 cm) ranged from 19-34, 22-62, and 19-58 g C kg-1 for open, spekboom, and nonspekboom sites, respectively. Whereas, mean inorganic C ranged from 2-9 g C kg-1 irrespective of sites, representing 4-22 % of total soil C. However, no significant differences were detected between degraded and intact sites for all (total, organic and inorganic) C stocks, attributed to variation in bulk density.
Spekboom soils contained significantly higher concentrations of exchangeable and water soluble Mg, Na, and K, and consequently had higher pH and EC compared to the other sites. Soils tended to be hydrophobic especially at shallower depths in the intact thicket irrespective of vegetation type, whereas soils from the adjacent open sites were not significantly hydrophobic. Macro-aggregates were considerably more stable under intact sites compared to open sites. The second experimental chapter investigated the effects of degradation and vegetation type on the stability and structural chemistry of SOC. This involved partitioning the soil organic matter into particulate and mineral-bound (stable) fractions, and then examining the relationships between the stable organic C fraction and various soil properties as an attempt to elucidate the stabilization mechanism(s). Particulate organic C ranged from 7.0, 9.3, and 14.4 g C kg-1 for open, spekboom, and nonspekboom respectively; representing 22-34 % of total SOC. Stable (mineral-bound) organic C accounted for the largest fraction ca. 60-66 % of total SOC; 28.0 and 26.2 g C kg-1 for spekboom and non-spekboom respectively, versus 17.2 g C kg-1 for open sites. It was concluded that SOC stability was influenced by the inherent residue quality (recalcitrance) rather than soil properties, attributed to the aliphatic (lipids and waxes) and highly aromatic nature of the spekboom litter substrate and particulate OM. These research findings are of fundamental significance in understanding soil organic matter stabilization in semi-arid environments. / AFRIKAANSE OPSOMMING: Gronde van semi–ariede streke het oor die algemeen 'n lae organiese materiaalinhoud, wat hoofsaaklik aan die heersende klimaatstoestande toegeskryf kan word. Tog, het die spekboomruigtes, geleë in die semi-ariede streek van die Oos-Kaap (Suid Afrika), onderskeidelik groot hoeveelhede grondkoolstof geakkumuleer. Om hierdie merkwaardige akkumulasie verder te verstaan, was 'n gedetailleerde ondersoek uitgevoer om die verspreiding, spesiasie en stabiliteit van die grondkoolstof direk onder spekboom (Portulacaria afra) en ander “nie-spekboom” plantegroei binne die intakte ruigte en van die aangrensende gedegradeer (oorbeweide), oop gras areas te evalueer.
In die eerste eksperimentele hoofstuk, is die verspreiding van organiese en anorganiese C, sowel as algemene grondeienskappe (pH, uitruilbare en wateroplosbare katione, hidrofobisiteit, water-stabiele aggregate) was in die intakte (spekboom en nie-spekboom) en degradeerde (oop) ruigtes ondersoek. Daar was geen betekenisvolle verskille in die C-inhoud (organies of anorganies) tussen die spekboom en nie-spekboom gronde in die intakte ruigtes gevind nie. Grond organiese koolstof (GOK) inhoud is grootliks deur die ruigte se agteruitgang beïnvloed, maar anorganiese C-voorrade was egter nie beïnvloed nie. Die gemiddelde organiese C-inhoud (0-50 cm) het van 19-34, 22-62 en 19-58 g C kg-1 onderskeidelik vir 'n oop, spekboom, en nie-spekboom areas gewissel. Die anorganiese C-inhoude het vanaf 2-9 g C kg-1 gewissel, ongeag van ligging, wat 4-22 % van die totale grond C uit maak. Daar is egter geen beduidende verskille tussen vervalle en heel terreine vir almal (totaal, organiese en anorganiese) C aandele opgespoor, toegeskryf word aan die variasie in die massadigtheid.
Spekboom gronde het beduidende hoër konsentrasies van uitruilbare en wateroplosbare Mg, Na, en K waardes bevat. Dit het ook hoër pH en EC, in vergelyking met die ander areas gehad. Gronde was geneig om hidrofobies te wees, veral op vlakker dieptes in die intakte ruigte, ongeag van die plantegroei, terwyl die gronde van die aangrensende oop areas nie beduidend hidrofobies was nie. Makro grond aggregate was aansienlik meer stabiel onder intakte ruigtes as in die oop areas. Die tweede eksperimentele hoofstuk het die gevolge van die weiding-geïnduseerde degradasie en tipe plantegroei op die stabiliteit en strukturele chemie van GOK ondersoek. Dit het die skeiding van die grond organiese materiaal in die vrye en mineraalgebonde (stabiele) fraksies behels. Daarna is die verhoudings tussen die stabiele organiese C fraksie en verskeie grondeienskappe ondersoek om die stabiliseringmeganisme(s) uit te lig. Die chemiese aard van die blare, plante oorblyfsels, fyn en minerale gebinde organiese C is met behulp van spektroskopie ondersoek. Vrye organiese C voorraad het van 7.0, 9.3, en 14.4 g C kg-1 vir oop, spekboom, en nie-spekboom onderskeidelik gewissel, wat ongeveer 23-34% van die totale GOK verteenwoordig. Stabiele (minerale gebind) organiese C-voorrade is vir die grootste fraksie ca. 60-66% van die totale GOK verantwoordelik. Dit was 28.0 en 26.2 g C kg-1 onderskeidelik vir spekboom en nie-spekboom, teenoor 17.2 g C kg-1 vir 'n oop area. Die mineraalgebonde GOK het geen noemenswaardige korrelasies met die ondersoekte grondeienskappe getoon nie. Dus is tot die gevolgtrekking gekom dat GOK stabilisering eerder deur die plante oorblyfsel se chemiese kwaliteit beïnvloed word. Strukturele chemiese karakterisering (13C CP-MAS KMR) van die spekboom afval en vrye C fraksie het gewys dat weerspannigheid die mees prominente meganisme van koolstof stabilisering van organiese koolstof in die gronde is. Dit word aan die alifatiese (lipiede en wasse) en sterk aromatiese aard van die spekboom substrate toegeskryf. Hierdie ondersoek het tot die fundamentele kennis van grond organiese materiaalstabilisering in 'n semi-ariede omgewings bygedra.
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