Thesis (MScAgric)--University of Stellenbosch, 2003. / ENGLISH ABSTRACT: Near infrared reflectance spectroscopy (NIRS) was evaluated as a tool to predict the chemical
composition of ostrich meat, mutton and feedstuffs. Seventy-three calibrations were developed. NIRS
analyses were conducted on an InfraAlyzer 500 spectrophotometer between 1100 and 2500 nm wavelengths.
Near infrared reflectance calibrations were developed for (i) the proximate chemical composition of
ostrich meat; (ii) the proximate chemical and mineral composition of mutton; (iii) the chemical composition
and digestibility of lupins, full-fat canola and the determination of alkaloids in lupins; (iv) the chemical
composition and digestibility of winter grains and maize; (v) the chemical composition and digestibility of
cereal hay, cereal straw, wheat stubble and alfalfa-grass/hay mixtures. The chemical composition of
different types of winter grain produced in the Western Cape area of South Africa, as well as the chemical
composition and digestibility of winter grain hay and straw produced in a Mediterranean rainfall area were
also determined.
Near infrared reflectance spectrometry proved to be successful for the prediction of crude protein (CP)
and fat in both animal species, as well as for ash and dry matter (DM) in freeze-dried mutton. Accurate
calibrations were also developed for certain minerals (K, P, Na, Mg, Fe and Zn).
Calibrations proved to be accurate for all the relevant chemical constituents in lupins, as well as the
DM, CP and fat calibrations in full-fat canola. The alkaloid calibration showed potential although more
samples should be included for a more accurate calibration. Winter grain calibrations were accurate for fat,
acid detergent fibre (ADF), in vitro organic matter digestibility (IVOMD), lysine and methionine. All
chemical composition calibrations of maize, except for ash, were accurate for future prediction. Chemical
composition calibrations of wheat stubble and alfalfa-grass hay mixtures resulted in prediction with similar
or slightly higher accuracy than calibrations reported in the literature. The calibrations developed for cereal
hay and straw were not suitable for prediction purposes. Possible reasons were discussed to explain these
inaccurate calibrations. Variation shown between different types of cereal grain (2-row barley, 6-row barley, oats, wheat and
triticale) accentuated the need for the analysis of different batches of grain produced under different
conditions for use in animal feed. The chemical composition and digestibility of winter grain straw and hay
were also obtained. These values provide a database for calculation of inclusion levels of these feedstuffs in
animal diets.
These investigations showed the NIRS to be a successful and rapid tool for the prediction of the
chemical composition of ostrich and lamb meat and locally produced feedstuffs. / AFRIKAANSE OPSOMMING: Naby infrarooi refleksie spektroskopie (NIRS) is geëvalueer as 'n metode om die chemiese
samestelling van volstruis- en skaapvleis, asook voedingsgewasse te voorspel. Drie en sewentig kalibrasies
is ontwikkel. NIRS ontledings is gedoen met ‘n InfraAlyzer 500 spektrofotometer tussen die golflengtes
1100 en 2500 nm.
Naby infrarooi refleksie kalibrasies is ontwikkel vir (i) die basiese chemiese samestelling van
volstruisvleis; (ii) die basiese chemiese en minerale samestelling van lamsvleis; (iii) die chemiese
samestelling en verteerbaarheid van lupiene en volvet kanola en die bepaling van alkaloïede in lupiene; (iv)
die chemiese samestelling en verteerbaarheid van wintergrane en mielies; (v) die chemiese samestelling en
verteerbaarheid van graanhooie, graanstrooie, koringstoppels and lusern-gras/hooi mengsels. Die chemiese
samestelling van verskillende tipes wintergrane wat in die Wes-Kaap omgewing van Suid-Afrika
geproduseer word, sowel as die chemiese samestelling en verteerbaarheid van wintergraanhooi en –strooi
wat geproduseer word in ‘n Mediterreënse reënval omgewing, is ook bepaal.
Naby infrarooi refleksie spektrofotometrie was suksesvol in die voorspelling van ru-proteïen (RP) en
vet in beide dierspesies, sowel as vir die bepaling van as en droë materiaal (DM) in gevriesdroogde
lamsvleis. Akkurate kalibrasies is ook ontwikkel vir sekere minerale (K, P, Na, Mg, Fe en Zn).
Kalibrasies ontwikkel vir die chemiese samestellings komponente in lupiene is reg deur die bank
akkuraat, sowel as die DM, RP en vet kalibrasies vir volvet kanola. Die alkaloïed kalibrasie het goeie
potensiaal getoon, alhoewel meer alkaloïedmonsters benodig word vir ‘n akkurate kalibrasie. Wintergraan
kalibrasies was akkuraat vir vet, suurbestande vesels (SBV), in vitro organiese materiaal verteerbaarheid
(IVOMV), lisien en metionien. Al die chemiese komponent kalibrasies vir mielies, behalwe die een vir as,
was akkuraat vir toekomstige bepalings. Chemiese komponent kalibrasies vir koring stoppels en luserngras/
hooi mengsels het akkuraatheid getoon wat gelyk, of effe beter, is as kalibrasies wat in die literatuur
opgeteken is. Kalibrasies ontwikkel vir graanhooie en graanstrooie was nie geskik vir
voorspellingsdoeleindes nie. Moontlike redes vir die onakkurate kalibrasies is volledig bespreek. Variasie gevind tussen verskillende tipes wintergrane (2-ry gars, 6-ry gars, hawer, koring en korog)
het die behoefte beklemtoon vir ontledings van grane geproduseer onder verskillende omgewingstoestande
vir gebruik in dierevoeding. Die chemiese samestelling en verteerbaarheid van wintergraanstrooi en –hooi is
ook bepaal. Hierdie waardes verskaf ‘n databasis vir berekening by insluiting van hierdie voergewasse in
diererantsoene.
Hierdie ondersoek het bewys dat NIRS ‘n suksesvolle en vinnige metode is vir die voorspelling van
die chemiese samestelling van volstruis- en lamsvleis en plaaslik geproduseerde voergewasse.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/16459 |
| Date | 12 1900 |
| Creators | Viljoen, Mariaan |
| Contributors | Hoffman, L.C., Brand, T.S., University of Stellenbosch. Faculty of Agrisciences. Dept. of Animal Sciences. |
| Publisher | Stellenbosch : University of Stellenbosch |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | English |
| Type | Thesis |
| Format | xv, 101 leaves : ill. |
| Rights | University of Stellenbosch |
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