[No abstract submitted] / Land and Food Systems, Faculty of / Graduate

No description available.

Graduation date: 1953

Fish meals, particularly British Columbia herring meals, and condensed herring solubles have been studied for their nutritive properties as supplements in poultry rations. Both commercially and experimentally prepared herring meals were used in the study. Protein quality in fish meals was investigated to ascertain what degree of variability exists in commercial samples and to obtain information regarding the effects of raw material, processing temperature and storage. On the basis of the Protein Index Values commercial fish meals appeared to vary in the quality of their protein content. Much of the variability amongst different meals could be ascribed to the nature of the raw material. Experiments were carried out in which herring meals prepared under controlled conditions from material of known origin were compared. It was shown that the value as a protein source for the growing chick of meals produced under a considerable range of drying temperatures was similar. Differences in the vitamin content of fish meal were found to be responsible for differences in the rates of growth of chicks fed herring meals which had been dried at high and low temperatures. With the basal rations employed, folic acid was the limiting nutrient when herring meal was used as the sole source of supplementary protein. The folic acid content of meals prepared from similar raw material was found to be markedly affected by the temperature at which the meals were dried. Chicks and poults fed rations formulated to be complete in the known nutrients grew at a faster rate when 2.5 to 5.0 percent of herring meal was added to the rations. It was concluded that herring meal contains a factor(s) not identified with any of the known vitamins. Condensed herring solubles was shown to be an effective vitamin supplement to practical type poult rations whether or not the ration contained herring meal. Extraction of the oil from herring meals did not improve the growth response of chicks to the use of the meals as protein supplements. Normal and extracted commercial flame-dried meal and experimentally prepared low-temperature-dried meal were compared in this regard. Storage of herring meals for one year at -25°, 21° and 37°, respectively, did not appear to affect the nutritive value of the meals as protein supplements for chick rations. Chemical changes did occur in the fat present in herring meals during storage. The amount of ether-soluble material decreased with the length of the storage period and the iodine value of the ether extract decreased. The addition to the meal of 0.15 percent butylated hydroxytoluene before storage prevented any decrease in ether extractability of the fat during a 9-month storage period and considerably reduced the drop in iodine value of the extract. / Land and Food Systems, Faculty of / Graduate

Thesis (Ph. D.)--University of Washington, 1992. / Vita. Includes bibliographical references (leaves [190]-202).

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.

The effect of fractionating flax, peas and canola on the digestibility of these ingredients in <i>Nile tilapia</i> was determined. Dehulling of flax, and processing peas and canola to pea protein concentrate and canola protein concentrate, resulted in significant increases in the energy and dry matter digestibilities of these products (P < 0.05). Protein digestibility was significantly improved by dehulling flax but there were no differences in the protein digestibilities of pea, canola and their protein concentrates. The ability of the most digestible ingredients from Experiment 1 to replace fish meal in tilapia diets was examined in a 9 week growth trial. The diet formulations were arranged in a 2 x 4 factorial design with 2 types of plant protein mixtures used to replace fish meal (simple: soyabean meal and maize gluten meal or complex: soyabean meal, maize gluten meal, dehulled flax, pea protein concentrate and canola protein concentrate) and 4 levels of protein originating from fish meal (100%, 67%, 33% and 0%). Diets were formulated to contain equal digestible protein (380 g kg-1) and digestible energy (17.63 MJ kg-1). Fifty six tanks containing 10 male <i>Nile tilapia</i> were used in this experiment. Fish were fed to apparent satiation twice daily for a total of 63 days and growth and feed intake was measured for the entire experimental period. On day 64 of the experiment, one fish per tank was euthanized and a 1 cm segment of small intestine was prepared for measurement of villus length. The average daily gains, specific growth rates and feed efficiencies of fish fed diets with 0% fish meal were significantly lower than fish fed diets with the 33, 67 or 100% fish meal levels. Fish fed the complex diets had significantly higher average daily gains, specific growth rates, feed:gain ratios and protein efficiency ratios than those fed the simple diets. Villus length decreased with decreasing levels of fish meal and increased with increased diet complexity but the effects were not significant. The results indicated that replacement of fish meal with a complex mixture of plant ingredients may allow a greater replacement of fish meal in diets fed to <i> Nile tilapia</i>.

The effect of fractionating flax, peas and canola on the digestibility of these ingredients in <i>Nile tilapia</i> was determined. Dehulling of flax, and processing peas and canola to pea protein concentrate and canola protein concentrate, resulted in significant increases in the energy and dry matter digestibilities of these products (P < 0.05). Protein digestibility was significantly improved by dehulling flax but there were no differences in the protein digestibilities of pea, canola and their protein concentrates. The ability of the most digestible ingredients from Experiment 1 to replace fish meal in tilapia diets was examined in a 9 week growth trial. The diet formulations were arranged in a 2 x 4 factorial design with 2 types of plant protein mixtures used to replace fish meal (simple: soyabean meal and maize gluten meal or complex: soyabean meal, maize gluten meal, dehulled flax, pea protein concentrate and canola protein concentrate) and 4 levels of protein originating from fish meal (100%, 67%, 33% and 0%). Diets were formulated to contain equal digestible protein (380 g kg-1) and digestible energy (17.63 MJ kg-1). Fifty six tanks containing 10 male <i>Nile tilapia</i> were used in this experiment. Fish were fed to apparent satiation twice daily for a total of 63 days and growth and feed intake was measured for the entire experimental period. On day 64 of the experiment, one fish per tank was euthanized and a 1 cm segment of small intestine was prepared for measurement of villus length. The average daily gains, specific growth rates and feed efficiencies of fish fed diets with 0% fish meal were significantly lower than fish fed diets with the 33, 67 or 100% fish meal levels. Fish fed the complex diets had significantly higher average daily gains, specific growth rates, feed:gain ratios and protein efficiency ratios than those fed the simple diets. Villus length decreased with decreasing levels of fish meal and increased with increased diet complexity but the effects were not significant. The results indicated that replacement of fish meal with a complex mixture of plant ingredients may allow a greater replacement of fish meal in diets fed to <i> Nile tilapia</i>.

No description available.

The variation in fatty acid composition between the "bound" and "free" lipid in stored anchovy meal was determined using gas-liquid chromatographic analysis. A model system of fresh anchovy oil on powdered lactalbumin was also studied to determine the changes in extractability and fatty acid composition which occur during oxidation. All of the lipid-protein systems examined were first extracted with hexane. The extracted protein was then extracted with choroform:: methanol (2:1 v/v), and finally digested in HCl and the hydrolysate extracted with diethyl ether. The chloroform : methanol extract and HCl digestion represented oil which was bound to the protein. Each lipid extract was interesterified with methanol to yield the corresponding methyl esters, and these esters were then analyzed by gas-liquid chromatography. Both quantitative and qualitative analysis was carried out using a diethylene glycol succinate packed column in a gas chromatograph equipped with a hydrogen flame detector. The results of these investigations showed that the oil from anchovy meal differed markedly in fatty acid composition from the corresponding fresh oil. Although the types of fatty acids found were identical to those in the fresh oil, there was considerable quantitative variation. These differences were characterized by smaller amounts of polyunsaturated fatty acids in the meal, and correspondingly larger amounts of saturated and monoenoic fatty acids. The greatest change occurred in the acid, 20:5. Anchovy meal contained a "bound" lipid fraction which varied in quantitative fatty acid composition with the readily extractable lipid. The fractions associated with the protein had higher proportions of 22:4, 22:5, and 22:6, with the acid digest fraction considerably lower in the monoenoic fatty acids. The oxidation of anchovy oil and anchovy oil methyl esters on lactalbumin produced a reduction in hexane extractable lipid with a corresponding increase in lipid which was soluble only in chloroform : methanol or after HCl hydrolysis. These changes were more drastic when untreated anchovy oil was used. The oxidation of anchovy oil methyl esters on lactalbumin produced a reduction in the amounts of polyunsaturated fatty acids present in the hexane extract. The other solvent extractions, however, yielded only higher molecular weight compounds which could not be analyzed by GLC. These observations led to the conclusion that the fatty acids formed compounds which interacted before being bound to the protein. / Graduation date: 1966