Thesis (MSc)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: A 240-day growth study was conducted to determine the suitability of soybean meal
(SBM) as an alternative protein source to fish meal (FM) in the diet of commercially
produced South African abalone (Haliotis midae). The suitability of SBM was
determined by a close evaluation of the following key factors: feed water stability,
morphological impact on the abalone intestine and the effect on the growth performance
of abalone.
The study was comprised of two phases: a fish meal replacement phase (Phase A) and
an enzyme treatment phase (Phase B). Diets used in Phase A consisted of a control
fish meal diet (Control=22%FM, 0%SBM), a fish meal-soybean meal diet
(FMSBM=20%FM, 15%SBM), a soybean meal-low diet (SBMlow=0%FM, 15%SBM)
and a soybean meal diet (SBM=0%FM, SBM30%). In Phase B, the FM diet and SBM
diet were used as basal diets (FME0 and SBME0). These diets were then treated with
three commercial enzyme products, namely, a β- glucanase (FME1 and SBME1),
xylanase (FME2 and SBME2) and α-D-galactosidase (FME3 and SBME3).
Subsequently, all three enzymes were combined to make two treatments (FME123 and
SBME123). With regard to the gut morphology and growth trials, a thirteenth energy
enhanced commercial animal protein-free diet (ECO) was used.
In Phase A (fish meal replacement), the findings revealed that water stability did not
differ significantly between treatments. In Phase B (enzyme treatment) however, the
water stability of β- glucanase treated feeds was significantly lower than that of the
control FM diet. It was also observed that in comparison to the control FM diet, soybean
meal based diets have a significantly greater effect on intestinal morphology.
With reference to Phase A (fish meal replacement), by the end of the 240 day growth
trial period, it was evident that animals fed on the commercial (ECO) diet were
significantly heavier than those given the control FM diet. With regard to final length in
mm, feed conversion ratio (FCR) and specific growth rate (SGR) for mass and length,
no differences between the treatments were noted. It was also found that the condition of the ECO fed animals was significantly better in comparison to the other treatment fed
animals. No significant differences were observed between the FM and three FMreplaced
diets however.
With reference to Phase B (enzyme treatment), it was noted that once again, after the
240 day period, abalone fed on the ECO diet were significantly heavier in terms of their
final weight when compared to those fed on the other diets. As in Phase A, no
differences in FCR and SGR for mass and length were observed. Measurements of the
animals’ final length (as observed on day 240) revealed that those fed on the ECO diet
were significantly longer than those given the FME1, SBME1 and SBME3 diets. At the
end of the trial, abalone fed on the ECO diet were also in significantly better condition
than those fed on the SBM, FME3 and FME123 diets. In terms of production
performance, no significant difference was found between the SBM diets and FM diets
and enzyme supplementation did not significantly increase the production performance
either. The results of this study therefore show that SBM has great potential to be used
as a FM-replacement diet. The improved performance of the ECO diet was expected
due to its energy content. / AFRIKAANSE OPSOMMING: ‘n Groeistudie is gedoen met die perlemoen (Haliotis midae) oor ʼn tydperk van 240 dae
om die geskiktheid van sojaboonoliekoek (SBM) as ‘n alternatiewe proteïenbron ter
vervanging van vismeel (FM) in die rantsoen te evalueer. Geskiktheid van SBM is
getoets aan die hand van waterstabiliteit van voer, morfologie van die
spysverteringskanaal en die invloed daarvan op groei van die perlemoen.
Die studie het uit twee fases bestaan naamlik ‘n vismeel (FM) vervangingsfase (Fase A)
gevolg deur ‘n ensiem behandelingsfase (Fase B). Die diëte wat gebruik was sluit in ’n
Kontrole dieet wat slegs vismeel as proteïenbron bevat (Kontrole = 22%FM, 0%SBM),
‘n 2de dieet wat beide vismeel en sojaboonoliekoekmeel bevat (FMSBM =20%FM, 15%
SBM), ‘n 3de dieet wat ‘n lae vlak sojaboonoliekoekmeel bevat (SBMlow =0%FM,
15%SBM) en 4de dieet met ʼn hoër sojaboonoliekoek vlak (SBM = 0%FM, 30% SBM).
Die basale diëte van Fase B was dieselfde as die FM en SBM diëte van Fase A (FME0
en SBM0) met die verskil dat dit met kommersiële ensieme behandel is. Die onderskeie
behandelings was gedoen met β-glukanase (FME1 en SBME1), xylanase (FME2 en
SBME2) en α-D-galactosidase (FME3 en SBME3) asook ‘n kombinasie van die drie
ensieme (FME123 en SBME123). ‘n Addisionele behandeling bestaande uit ‘n
kommersiële diereproteïenvrye dieet (ECO) is as bygevoeg as kontrole vir die histologie
gedeelte van die proef.
Tydens Fase A is gevind dat waterstabiliteit van die onderskeie diëte nie betekenisvol
verskil het nie. Tydens Fase B het ensiembehandeling met
β-glukanase egter aanleiding gegee tot betekenisvolle laer waterstabiliteit van FME1 en
SBME1 diëte in vergelyking met die FM dieet. Histologiese ontledings het getoon dat
die SBM diëte ‘n groter negatiewe effek op die morfologie van die spysverteringkanaal
gehad het as die kontrole FM dieet.
Fase A het getoon dat die ECO dieet beter groeiresultate opgelewer het as die FM
dieet, in terme van liggaamsmassa en kondisiefaktor van die perlemoen. Finale skulplengte (mm), voeromsetverhouding (VOV) en spesifieke groeitempo (SGT) vir
massa en lengte was egter nie betekenisvol verskillend vir enige van die behandelings
nie. Geen betekenisvolle verskille is ook gevind tussen die FM en enige van die FM
vervangingsdiëte nie.
Resultate vir Fase B het getoon dat diere wat die ECO dieet gevoer is betekenisvol
swaarder was as diere wat ander voere gevoer is. Geen betekenisvolle verskille is
waargeneem vir VOV en SGT van massa en lengte nie. Finale lengte van die diere wat
ECO gevoer is was langer as die van die FME1, SBME1 en SBME3 diëte. Die ECO
diere het ook in betekenisvol beter kondisiefaktor vertoon as diere wat SBM, FME3 en
FME123 diëte gevoer is. Geen betekenisvolle verskille in produksie parameters is
opgemerk tussen die FM en SBM diëte nie en die toevoeging van ensieme het ook nie
‘n betekenisvolle invloed gehad nie. Die gevolgtrekking is dat sojaboonoliekoekmeel
suksesvol aangewend kan word vir die vervanging van vismeel in perlemoen diëte.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/20412 |
| Date | 03 1900 |
| Creators | De Villiers, Christopher Murray |
| Contributors | De Wet, Lourens, Pieterse, Elsje, 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 | 147 pages : illustrations |
| Rights | Stellenbosch University |
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