Thesis (MScAgric)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: Starch is the main component of cereal grains and is usually the primary energy source for pigs and
poultry. Feed manufacturing can adopt several measures, including physical treatments such as milling
or pelleting and other techniques, such as enzyme treatment, to disrupt cell structure. Grinding and
pelleting are the most common food processing methods used for pigs. However, pelleting of complete
balanced feeds is no longer such an economical proposition due to rising energy and equipment costs;
therefore this cost has to be outweighed by an increased production efficiency. It has been known for
many years that grinding is an essential prerequisite for the satisfactory blending of the ingredients of a
multi-component food. Feed cost represents the major item in the cost of animal production. Without
doubt, research and production efforts will continue to refine feed processing techniques to reduce the
cost of feed and to increase the value of feed for a target animal. The possibilities for improvements in
feed are endless; however the cost of each innovation must be carefully weighed against demonstrated
improvements in animal performance.
Experiment 1: The effect of feed processing techniques on weanling pig growth-performance
The effects of processing of the carbohydrate source and the feed on growth performance of commercial
Landrace x Large White piglets (n=480) weaned at 28 ± 2 d were investigated. Two processing
combinations of the carbohydrate source were used with 3 processing conditions of the diet in a 2 x 3
factorial design. The pigs were blocked by weight (7.196 ± 2.03 kg BW) and then allotted randomly to 1
of 6 dietary treatments. Ten pens of 8 piglets each were fed with each dietary treatment. The two main
processing conditions of the carbohydrate source were raw or extruded maize and the 3 processing
conditions of the diet was meal or pelleted or extruded. No carbohydrate processing x diet processing
interactions were observed (P > 0.05) for ADG, ADFI or FeR. In this experiment, extrusion of the
maize led to an significant decrease in FeR efficiency (P < 0.05) (1.57 vs. 1.42) when compared to a
raw maize diet. Pelleting a diet had no significant effect (P > 0.05) on ADG but tended to decrease ADFI
(P < 0.07) and significantly improve FeR efficiency (1.49 vs. 1.66) when compared to a meal diet.
Extruding the whole diet did not have any significant (P > 0.05) effect on ADG but tended to decrease
ADFI (P < 0.07) and gave an significant improvement in FeR when compared to a meal diet (1.34 vs.
1.66). This processing technique also gave a significant improvement (P < 0.01) in FeR when compared
to a pelleted diet (1.34 vs. 1.49).
Experiment 2: The effect of pig feed processing conditions on pig metabolism parameters
The effects of processing of the carbohydrate source and the diet on certain metabolism and production
parameters of commercial Landrace x Large White pigs (n=24) were investigated. Two processing
combinations of the carbohydrate source were used with 3 processing combinations in a 2 x 3 factorial
design. Six diets were formulated on an iso-nutrient basis (14.48 MJ/kg metabolizable energy (ME), 23.01 crude protein (CP), 1.092% lysine, 0.742% methionine and cystine and 0.271% tryptophan on a
DM basis). The pigs were blocked by weight (26.02 ± 0.25 kg BW) and then allotted randomly to I of 6
dietary treatments. The carbohydrate source was raw or extruded maize and the diets was meal or
pelleted or extruded. No carbohydrate processing x diet feed form interactions were observed (P > 0.05)
for dry matter intake (DMI), dry matter digestible energy (DE), Nitrogen (N) or dry matter intake
(DMI). In a metabolism and nitrogen (N) balance study, apparent N digestibility, digestible energy and
metabolizable energy contents were found not to be significantly (P > 0.05) influenced by carbohydrate
or diet processing. / AFRIKAANSE OPSOMMING: Stysel is die hoof komponent in grane en is gewoonlik die primêre verskaffer van energie vir varke en
pluimvee. Voermeulens kan verskeie metodes implementeer, insluitend fisiese behandeling soos bv.
maal, verpilling en ensiem behandelings, om sel struktuur te verander. Maal en verpilling is die mees
algemene prosessering metodes wat vir varkvoer gebruik word. Maar, verpilling van totaal
geballanseerde voere is nie meer so ekonomies geregverdig nie as gevolg van stygende energie en
masjinerie koste. Daarom moet die koste van voervervaardiging oorbrug word deur 'n verhoogde
produksiedoeltreffendheid. Dit is al lankal bekend dat maal 'n voorvereiste is vir effektiewe vermenging
van grondstowwe van 'n multi-komponent voer. Voerkoste verteenwoordig die hoof item van die koste
van intesiewe diereproduksie. Voedingskudiges sal sonder twyfel voortgaan om voerprosessering te
verfyn om so die koste van die rantsoen te verlaag en om die waarde van die rantsoen te verhoog vir die
dier. Die moontlikhede is veelvuldig, maar die koste van elke ontwikkeling moet opgeweeg word teen
verhoogde diereproduksie.
Eksperiment 1: Die effek van voerprosesserings-tegnieke op speenvark groei en produksie
'n Proef is uitgevoer om die prosesseringseffek van 'n koolhidraat bron en voer op die groei van Landras
x Groot Wit speenvarke (n=480) wat gespeen is op 28 ± 2 d te bepaal. Twee prosesserings-kombinasies
van die koolhidraat bron en drie prosesserings-kondisies van die dieet is in 'n 2 x 3 faktoriaal ontwerp
uitgevoer. Die varkies is geblok volgens massa (oorspronklik 7.196 kg ± 2 kg) en toe ewekansig in I van
6 dieët behandelings ingedeel. Die proefdiëte is vir lO hokke varkies gevoer, elke hok het 8 varkies in
gehad. Die twee hoof prosesserings-kondisies van die koolhidraat bron was rou of gaar mielies en die
drie prosesserings-kondisies van die dieët was meelof gaar of geëkstrueer. Geen koolhidraat
prosesserings x dieët prosesserings interaksie van die dieët was opgemerk (P > 0.05) vir gemiddelde
daaglikse toename (GOT), gemiddelde daaglikse voer inname (GDVI) of voer omset doeltreffendheid
(VOD) nie. In die eksperiment was die VOD van die geëkstrueerde mielie dieët, statisties betekenisvol
laer (P < 0.05) (1.57 vs.1.42) as die rou mielie dieët. Verpilling van die dieët het geen statisties
betekenisvolle effek (P > 0.05) op GDV! gehad nie, maar die VOD was statisties betekenisvol (P < 0.05)
beter (1.49 vs. 1.66) wanneer dit met die meel dieët vergelyk word. Ekstrusie van die dieët het geen
statisties betekenisvolle effek op GOT en GOVI gehad nie, maar die VOD was statisties betekenisvol (P
< 0.05) beter wanneer dit met die meel (1.34 vs. 1.66) en verpilde dieët (1.34 vs 1.49) vergelyk word.
Eksperiment 2: Die effek van voer prosessering op vark metabolisme parameters
'n Eksperiment is uitgevoer op Landras x Groot Wit bere (n=24) om die effek van prosessering van 'n
koolhidraat bron en voer te bepaal. Twee prosesserings-kombinasies van die koolhidraat bron en drie
prosesserings-kondisies van die dieët is in 'n 2 x 3 faktoriaal ontwerp uitgevoer. Ses diëte is geformuleer op 'n iso-nutriënt basis (14.48 MJ/kg metaboliseerbare energie (ME), 23.01 ru-proteïen (RP), 1.092%
lisien, 0.742% metionien and sistien en 0.271 % tryptofaan op 'n droeë materiaal (DM) basis). Die varke
is geblok volgens massa en ewekansig aan 1 van 6 diëte toegeken. Die koolhidraat bron was gaar of rou
mielies en die diëte was meel, verpil of geëkstrueer. Geen koolhidraat-prosessering x dieet interaksie is
opgemerk (P > 0.05) nie. In 'n metabolisme en stikstof (N) balans-studie is daar gevind dat DM
verteerbaarheid, skynbare N verteerbaarheid, verteerbare energie (GE) en ME inhoud nie beduidend
deur die behandelings beïnvloed word nie.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/53106 |
| Date | 12 1900 |
| Creators | Crots, Frans (Francois Engelbertus) |
| Contributors | Ekermans, L. G., Hoffman, L. C., Stellenbosch University. Faculty of AgriSciences. Dept. of Animal Sciences. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | Unknown |
| Type | Thesis |
| Format | 91 p. : ill. |
| Rights | Stellenbosch University |
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