Please read the abstract in the section 00front of this document / Dissertation (MSc (Zoology))--University of Pretoria, 2006. / Zoology and Entomology / unrestricted

The use of color coded prompts to influence students' food selections in choosing a balanced meal was investigated. Yellow, green, blue, and orange dots, representing the four major food groups, grains, fruit and vegetables, dairy, and meat respectively were displayed at the point-of-selection on food entree cards along the serving line of a college dining hall. Two grain servings, two fruit/vegetable servings, one dairy serving, and one meat serving, were suggested as the optimal combination for a balanced meal. The results indicated that the prompts, although noticed and understood by the majority of the students, did not significantly influence their food selections. These findings are inconsistent with earlier studies substantiating the effectiveness of color coded prompts at the point-of-selection in influencing food choices. Implications are discussed.

The objectives of this study were to determine the nature of data recorded on the Road to Health Card (RtHC) and its utilisation by nurses at primary health care setting, comparing it with norms and standards on the RtHC guideline, and to provide guidelines for optimal utilisation of the RtHC by health workers. A quantitative nonexperimental descriptive method was used. Two methods were used to collect data; document analysis of the RtHC and structure observation of nurses. A structured exit interview of caregivers was conducted to validate observations from nurses. A sample size of 18 nurses from all categories from six clinics was observed, and 36 RtHC of children under five years of age were analysed. Results indicated that data recorded on the RtHC was mostly inaccurate, incomplete and not interpreted. The study identified a need to train health workers on optimal utilisation of the RtHC facilitating health improvement of children under five years of age. / Health Studies / M.A. (Health Studies)

The objectives of this study were to determine the nature of data recorded on the Road to Health Card (RtHC) and its utilisation by nurses at primary health care setting, comparing it with norms and standards on the RtHC guideline, and to provide guidelines for optimal utilisation of the RtHC by health workers. A quantitative nonexperimental descriptive method was used. Two methods were used to collect data; document analysis of the RtHC and structure observation of nurses. A structured exit interview of caregivers was conducted to validate observations from nurses. A sample size of 18 nurses from all categories from six clinics was observed, and 36 RtHC of children under five years of age were analysed. Results indicated that data recorded on the RtHC was mostly inaccurate, incomplete and not interpreted. The study identified a need to train health workers on optimal utilisation of the RtHC facilitating health improvement of children under five years of age. / Health Studies / M.A. (Health Studies)

Thesis (MNutr--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Introduction Malnutrition, in both adults and children, is a problem worldwide with negative health consequences. The World Health Organization (WHO) and Food and Agricultural Organization (FAO) of the United Nations (UN) therefore initiated the implementation of country-specific food-based dietary guidelines (FBDGs) to be used as an educational tool to address nutrition-related health issues. They further suggested consumer testing to evaluate the comprehension and cultural acceptability thereof prior to the release of country-specific FBDGs. Focus group discussions (FGDs) were recommended for consumer testing. Aim The aim of this study was to assess the comprehension and applicability of the 2007 version of the preliminary South African paediatric food-based dietary guidelines (PFBDGs) for healthy infants aged 6–12 months in Soshanguve and Ga-Rankuwa. Specific objectives included qualitative evaluation of exposure to preliminary PFBDGs, participants’ interpretation thereof, cultural acceptability and practical application of the guidelines. Socio-demographic information was collected to determine whether these factors could potentially exert an influence on the comprehension and applicability of the FBDGs. This study could further inform emerging efforts to update public health initiatives to educate mothers/caregivers of infants. Methodology An observational, cross-sectional study design was followed, incorporating both qualitative and quantitative research methods. FGDs were utilised to assess comprehension of the PFBDGs and gather insight into perceptions, attitudes and appropriateness of the PFBDGs. Quantitative data were collected by means of a questionnaire regarding the socio-demographic profiles of participants. Setting This study focused on two small, densely populated towns, Soshanguve and Ga-Rankuwa, in the north western district of Tshwane in the Gauteng province of South Africa. The areas represent relatively low socio-economic communities that include a mix of formal and informal urban setting. Participants Twenty-seven Northern Sotho-speaking mothers and caregivers of infants aged 6–12 months participated in a total of six FGDs. Each FGD was attended by between three and six participants. Results None of the participants had previous exposure to the PFBDGs, although they were familiar with most of the concepts. Guidelines were generally well received and understood, but a few were misinterpreted; particularly those pertaining to “enjoy time with your baby”, “increase your baby’s meals to five times per day” and “teach your baby to drink from a cup”. These needed further explanation and rephrasing by the investigator to improve their comprehensibility. The guideline pertaining to breastfeeding was the most familiar, well accepted and most generally applied. Quantitative results indicated no significant difference between the socio-demographic profiles of participants in Soshanguve and Ga-Rankuwa. Participants’ education level, employment status and housing conditions were considered a good representation of the population. It appears that socio-demographic circumstances may affect exposure to, and interpretation and application of the PFBDGs. Conclusion Many of the adjustments recommended from this research is consistent with the changes incorporated in the recently published revised PFBDGs. Supportive documentation, educational material and health campaigns tailored to specific socio-demographic groups may further enhance the interpretation of the revised guidelines and their exposure to the public, once tested and adopted. / AFRIKAANSE OPSOMMING: Inleiding Wanvoeding onder kinders en volwassenes, is ʼn wêreldwye probleem wat, as dit nie aangespreek word nie, ernstige gesondheidsgevolge kan inhou. Die Wêreldgesondheidsorganisasie (WGO) en die Voedsel-en-landbou-organisasie (VLO) het die implementering van voedselgebaseerde dieetriglyne (VGDR) spesifiek aan elke land geïnisieer sodat dit as opleidingshulpmiddel kan dien om voedselverwante gesondheidsprobleme op te los. Daar is voorgestel dat verbruikers die riglyne in fokusgroepbesprekings (FGBs) evalueer om begrip en die kulturele toepaslikheid van bevolking-spesifieke riglyne te toets voordat dit bekendgestel word. Doel Die doel van die studie was om begrip en die toepassing van die 2007 weergawe van die voorlopige Suid-Afrikaanse pediatriese voedselgebaseerde dieetriglyne (PVGDR) vir gesonde kinders van 6–12 maande te bepaal. Spesifieke doelwitte het kwalitatiewe evaluering ten opsigte van blootstelling, deelnemers se interpretasie, kulturele aanvaarbaarheid en praktiese toepassing van die riglyne ingesluit. Sosiodemografiese inligting is ingesamel om te bepaal of daar ʼn verband bestaan tussen hierdie omstandighede en die begrip en toepassing van PVGDR’s. Hierdie studie kan toekomstige pogings ondersteun om openbare-gesondheidsprogramme by te werk en om moeders en versorgers oor babas in te lig. Ontwerp Die studieontwerp was ’n waarnemende deursnit met kwalitatiewe en kwantitatiewe navorsingsmetodes. FGBs was gebruik om die begrip van die PVGDR’s te bepaal en insigte oor die persepsies, houdings en geskiktheid van die PVGDR’s in te samel. Kwantitatiewe data is ingesamel met ʼn vraelys oor die sosiodemografiese profiele van deelnemers. Omgewing Die studie het gefokus op twee klein, digbevolkte stedelike gebiede, Soshanguve en Ga-Rankuwa in Tshwane, die noord-westelike distrik van die provinsie Gauteng in Suid-Afrika. Die areas verteenwoordig relatief lae sosio-ekonomiese gemeenskappe met ʼn mengsel van formele en informele stedelike nedersettings. Deelnemers Die studiegroep het 27 Noord-Sotho-sprekende moeders en versorgers ingesluit wat aan altesaam 6 FGB’s deelgeneem het. Tussen drie en ses deelnemers het elke FGB bygewoon. Resultate Geen deelnemers was voorheen aan PVGDR’s blootgestel nie, hoewel die meerderheid met meeste van die begrippe bekend was. Die riglyne was oor die algemeen goed aanvaar en verstaanbaar, maar ʼn paar was verkeerd geïnterpreteer; veral “geniet tyd saam met jou baba”, “vermeerder jou baba se maaltye na vyf kere per dag” en “leer jou baba om uit ʼn koppie te drink”. Verduideliking en herformulering was nodig om begrip te verbeter. Die riglyne oor borsvoeding was die bekendste, was die beste aanvaar en was in die algemeen toegepas. Kwantitatiewe resultate het aangedui dat die sosiodemografiese profiel van deelnemers uit Soshanguve en dié uit Ga-Rankuwa nie beduidend verskil nie. Deelnemers se opleidingsvlak, werkloosheidstatus en huislike omstandighede het die populasie goed verteenwoordig. Daar is bevind dat sosiodemografiese omstandighede blootstelling aan en begrip en toepassing van PVGDR’s kan beïnvloed. Gevolgtrekking Baie van die wysigings wat voorgestel is deur hierdie studie, stem ooreen met die verandering wat aangebring is in die onlangs gepubliseerde hersiene PVGDR’s. Ondersteunende dokumente, opvoedkundige materiaal en gesondheidsveldtogte vir spesifieke sosiodemografiese groepe sal die korrekte interpretasie van riglyne asook openbare bewusmaking bevorder. Die riglyne kan, met minimale aanpassings, suksesvol as ʼn voedingsverwante opvoedkundige hulpmiddel in die gemeenskap gebruik word. Baie van hierdie aanpassings is reeds aangebring tydens die ontwikkeling van die veranderde PVGDR’s. Die bevindinge van die studie kan ʼn kernbydrae tot die voorstelle lewer, en aanduidings vir voorstelle vir verdere ontwikkeling en evaluering oplewer.

Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: The nutrient requirements for breeding ostriches are currently not well-defined. Quantification of the nutrient requirements will improve the financial wellbeing of the industry. A study of the growth of the reproductive organs and liver, together with various production studies, were therefore undertaken in order to gain knowledge about the nutrition of breeding ostriches, thereby quantifying the nutrient requirements of breeding ostriches. Various studies were conducted to determine the influence of dietary protein, amino acids and energy on production levels of breeding ostriches. In a first study, five diets, varying in crude protein (CP) but with a constant energy content of 9.2 MJ ME/kg feed, were provided at a feed intake level of 2.5 kg/bird/day. The dietary CP levels were 7.5%, 9.1%, 10.8%, 12.3% and 14.0%. No differences (P>0.05) between treatments (total eggs per female per season) were found for number of unfertilized eggs (eggs per female per season; 8.9±0.8), dead-in-shell chicks (8.0±0.5), number of chicks hatched (19.1±1.1) and change in mass of females (-16.2±1.6kg). A tendency was observed for a difference in total egg production (mean and standard error; 39.1±3.6; P=0.08). The 12.3% CP diet caused the lowest (P<0.05) change in live mass (-3.8±2kg) for male birds. No interaction (P>0.05) occurred between the genotype of the bird and the dietary protein concentration for both egg and chick production. In a second study, six diets varying in ME (MJ ME/kg feed), were provided at an average feed intake level of 3.4 kg/bird/day. The levels were 7.5, 8.0, 8.5, 9.0, 9.5 and 10.0 MJ ME/kg feed respectively. No differences (P>0.05) were observed for total eggs produced per female per season (44.8±7.8), number of chicks hatched (15.4±4.1), number of infertile eggs (11.5±3.8), number of dead-in-shell eggs (12.1±3.2) and change in mass of females (10.7±3.6kg). Males increased linearly (y=2.4x + 2.45; R2=0.09; P<0.05) in live mass as the dietary energy content increased. Two eggs per diet per month were analyzed for crude protein, crude fat and trace elements, and one egg per diet per month was analyzed for fatty acid composition. Eggs from the first and last month of the season were subjected to amino acid analysis. Analysis of variance showed no difference in crude protein and fat (P>0.05) content of eggs between the experimental diets, as well as for the calcium content of eggshells. The proline content differed (P<0.05) between the diets. The C18:3n-3 (linoleic acid) content of the eggs increased (P<0.05) amongst the dietary treatments. Crude protein, fat and C18:3n-3 content in eggs increased (P<0.05) for the number of the egg in the laying cycle. In a third study, the feed intake of breeding ostriches, as affected by dietary energy content was investigated. Average feed intake (kg feed/bird/day) was not affected (P>0.05) at any dietary energy level when levels of 8.0, 8.7, 9.4, 10.1, 10.8 and 11.5 MJ ME/kg feed were provided. The mean and standard error was 3.7±0.2kg. The production of breeding female ostriches was not influenced by dietary ME and protein at these feed intake levels. Ostrich birds do not have the ability to regulate their feed intake at any dietary energy level as used in this study. The amount of nutrients deposited in the eggs had no influence on the reproductive efficiency of the breeding female ostrich. The experiments also revealed that female breeding ostriches were independent of dietary energy and protein as used in this study for the mean frequency of egg laying at various dietary protein and energy levels (P>0.05). In a fourth study, the growth and development of the reproductive organs of female birds at the onset of the breeding season were investigated. The amount of nutrients needs to be determined in order to support the growth of the reproductive organs during the breeding season, due to the fact that these organs are linked to egg production. It was thus necessary to investigate whether the reproductive organs grew and developed during a season. The first slaughter interval was conducted at the start of the breeding season. The ovary, oviduct and liver were collected, weighed after each slaughter and analyzed. Ovary and oviduct were analyzed for crude protein and fat. No differences (P>0.05) were observed between the different slaughter intervals for the mass, crude protein and fat content of both organs. No trend (P>0.05) in the weight of the oviduct could be observed over the 49-day period, this weight being highly correlated with body weight; whereas the ovary weight tended to be correlated with the time after the onset of the breeding period, although the variation in weights, both within and between weighings, was very high. The variation in the weight of the ovary probably reflects differences in the laying pattern of individuals. The number of follicles were not affected (P>0.05) by the number of days after mating. Livers were assessed for crude protein and fat, but no difference (P>0.05) was detected between the intervals, but the weight difference amongst the slaughter intervals was significant (P<0.05), suggesting that the ostriches used liver reserves to supplement nutrients that obtained from the diet for the development of the reproductive organs. This data will be used in an optimising model (Brand & Gous, 2006) to predict the nutrient requirements of female breeding ostriches. This study suggests that the female breeding ostrich might need additional protein during the first 7 weeks of the breeding season. Results from Chapter 4 and previous studies were used to calculate the energy, protein and amino acid requirements for the egg production and maintenance of the breeding female ostrich. Two methods were used to determine the energy requirement for egg production. The Metabolisable Energy requirement for egg production (MEe) and efficiency of ME utilization for energy deposition in the egg (ko) was calculated as 12.2 MJ (for an average size egg of 1.4kg) and 0.8 respectively. The Effective Energy requirement for egg production (EEe) and maintenance (EEm) was calculated as 15.9 MJ/day and 17.1 MJ/day respectively. Average total daily protein requirement (TPt) was calculated as 175g day. The amino acid requirements for maintenance and egg production is also provided, which is lower than previous studies. This study also provides evidence that the nutrient requirements are different for every month of the breeding season. / AFRIKAANSE OPSOMMING: Tans heers daar onsekerheid oor die voedingsbehoeftes van volstruis broeivolstruise. Kwantifisering van die voedingsbehoeftes sal ‘n finansiële hupstoot aan die industrie gee. ‘n Groeistudie van die reproduksie-organe en lewer, tesame met ‘n aantal produksie-studies, is uitgevoer om inligting oor die voedingsbehoeftes van volstruis broeivoëls te versamel. Daarby is die voedingsbehoeftes teoreties bereken. ‘n Aantal studies was uitgevoer om die invloed van dieët proteïen en aminosure en energie op produksie-data te bepaal. Eerstens is vyf diëte, wisselend in ru-proteïen (RP) en beperk tot ‘n inname van 2.5 kg/voël/dag, aan broeivolstruise gevoer. Die RP van elke dieët was 7.5%, 9.1%, 10.8%, 12.3% en 14.0%. Die energiewaarde van die voer is konstant by 9.2 MJ ME/kg voer gehou. Geen verskille (P>0.05) was tussen die behandelings waargeneem vir aantal geil eiers (totale eiers geproduseer per voël per seisoen; 8.9±0.8), aantal dood-in-dop (8.0±0.5), aantal kuikens (19.1±1.1) en verandering in massa van wyfies (-16.2±1.6kg) nie. ‘n Neiging (P=0.08) is wel waargeneem vir totale aantal eiers geproduseer. Die gemiddelde en standaard fout was 39.1±3.6. Die 12.3% dieët het tot die laagste verandering (P<0.05) in lewendige massa (-3.8±2kg) vir die mannetjies gelei. Geen interaksie (P>0.05) was tussen die genotipe en dieët proteïen konsentrasie vir beide eier- en kuikenproduksie opgemerk nie. In ‘n tweede studie is ses diëte, variërend in ME (MJ ME/kg voer), by ‘n gemiddelde tempo van 3.4 kg/voël/dag gevoer. Die verskillende ME-vlakke was 7.5, 8.0, 8.5, 9.0, 9.5 en 10.0 MJ ME/kg voer. Geen betekenisvolle verskille (P>0.05) is vir totale eiers geproduseer per voël per seisoen (44.8±7.8), aantal kuikens uitgebroei (15.4±4.1), aantal geil eiers (11.5±3.8), aantal dood-in-dop eiers (12.1±3.2) en massa verandering van wyfies (10.7±3.6kg) opgemerk nie. Die mannetjies het toegeneem in liggaamsmassa (P<0.05) soos daar ‘n toename was in die energievlak van die dieët. Twee eiers per dieët per maand is vir ru-proteïen, vet en spoorelemente, en een eier per diet per maand vir vetsure ontleed. Eiers van die eerste en laaste maand van die seisoen is ontleed vir aminosure. Analise van variansie het aangetoon dat daar geen verskille (P>0.05) bestaan vir die ru-proteïen en vetinhoud van die eiers by die verskillende eksperimentele diëte, asook die kalsiuminhoud van die eierdoppe. Prolien vlakke het tussen die diëte verskil (P<0.05). Die C18:3n-3 (linoleïensuur) inhoud van die eiers het verskil (P<0.05) tussen die dieët behandelilngs. Vir die hoeveelste eier in die lê siklus het die ru-proteïen-, vet- en C18:3n-3 inhoud van die eiers verhoog (P<0.05). In ‘n derde studie is ondersoek ingestel na die voerinname van die broeivolstruise soos moontlik beïnvloed deur die energievlak van die dieët. Gemiddelde voerinname (kg voer/voël/dag) is nie (P>0.05) deur die verskillende dieët energie vlakke van 8.0, 8.7, 9.4, 10.1, 10.8 en 11.5 MJ ME/kg voer beïnvloed nie. Die gemiddelde en standaardfout was 3.7±0.2kg. Die produksie van broeivolstruise nie deur verskillende dieëtvlakke van proteïen en energie by vlakke soos gevoer in hierdie studie geraak nie. Broeivolstruise in hierdie studie het nie die vermoë gehad om hul voerinname te beheer by enige dieët energievlak soos gebruik nie. Die aantal nutriënte wat in die eiers neergelê is, het geen bydrae tot die reproduksievermoë van die wyfie gehad nie. Die studie het verder bewys dat die gemiddelde frekwensie van eier-lê by wyfies onafhanklik was by dieët-energie en -proteïenvlakke (P>0.05) soos in hierdie studie gebruik. In ‘n vierde studie is die groei en ontwikkeling van die reproduksie-organe van die wyfies bestudeer tydens die aanvang van die broeiseisoen. Die hoeveelheid of konsentrasie van voedingstowwe moes bepaal word om die groei van die reproduksie-organe te ondersteun tydens die broeiseisoen, omdat hierdie organe aan eierproduksie gekoppel is. ‘n Studie is derhalwe uitgevoer om te bepaal tot watter mate die reproduksie organe groei en ontwikkel tydens die broeiseisoen. Die eerste slagting is uitgevoer op die dag van afkamp. Die ovaria, ovidukt en lewer is versamel, geweeg en ontleed. Die ovaria en ovidukt is ontleed vir ru-proteïen en vet. Geen verskille (P>0.05) is tussen die verskillende slagtings vir die gewig, ru-proteïen en vetinhoud vir beide organe opgemerk nie. Geen betekenisvolle tendens in die gewig van die ovidukt is waargeneem oor die 49-dae periode nie, maar die gewig was hoogs gekorreleerd met liggaamsmassa. Ovaria-gewig het geneig om gekorreleerd te wees met die aantal dae na afkamp. Variasie binne en buite die gewigte was baie hoog. Die aantal follikels teenwoordig is nie beïnvloed (P>0.05) deur die aantal dae na paring. Die lewers is ontleed vir ruproteïen en vet, maar geen verskille (P>0.05) is tussen die intervalle opgemerk nie, maar die gewigte van dag 0 en 49 na paring het verskil (P<0.05). Dit kan aangevoer word dat die voëls moontlik lewer reserwes gebruik het om die voedingstowwe van die dieët te supplementeer vir die ontwikkeling van die reproduksie-organe. Data uit hierdie studie kan gebruik word in ‘n optimiseringsmodel (Brand & Gous, 2006) om die voedingsbehoeftes van broeivolstruise te bepaal. Hierdie studie beveel aan dat die broeiwyfie moontlik addisionele proteïen tydens die eerste sewe weke van die broeiseisoen benodig. Resultate van Hoofstuk 4 en vorige studies is gebruik om die energie- proteïen- en aminosuurbehoefte vir eierproduksie en onderhoud van broeivolstruise te bereken. Twee metodes is gebruik om die energiebehoefte vir eierproduksie te bereken. Metaboliseerbare Energie behoefte vir eierproduksie (MEe) en effektiwiteit van ME benutting vir energie deponering in eier (ko) is onderskeidelik as 12.2 MJ (vir ‘n eier wat gemiddeld 1.4kg weeg) en 0.8 bereken. Effektiewe Energie behoefte vir eierproduksie (EEe) en onderhoud (EEm) was onderskeidelik as 15.9 MJ/dag en 17.1 MJ/dag bereken. Die gemiddelde daaglikse proteïenbehoefte (TPt) is as 175g proteïen/dag bereken. ‘n Aanduiding van die aminosuur behoefte vir onderhoud en eierproduksie word ook gegee, wat laer is as vorige studies.

Thesis (PhD(Agric) (Animal Sciences))--University of Stellenbosch, 2006. / This project consisted of five studies. The objectives were to determine the essential amino acid (AA) requirements of growing woolled lambs (Merino and Dohne Merino) and the essential AA profile of duodenal digesta pre-dominantly derived from microbial protein. The limiting essential AA`s in high rumen degradable protein (RDP) diets to growing lambs, where microbial protein is the primary source of AA`s, were also identified. The first study determined the essential AA profile of duodenal protein on a high rumen degradable diet and evaluated the impact of dietary RDP concentration and source [true RDP vs. non-protein nitrogen (NPN)] on the AA composition of supplied in the duodenum. The first trial in this study evaluated the effects of increasing true RDP levels on the essential AA composition of duodenal protein primarily derived from rumen microbes. The lambs had free access to wheat straw and fresh water. The daily RDP supplements were administered in two equal doses into the rumens through rumen cannulas at 07:00 and 19:00. Duodenal digesta was extracted with 6h intervals through T-type cannulas, inserted proximally to the common bile duct. Sampling time was advanced 2h every day to obtain duodenal samples on every even hour of a 24h period after three days. As expected, deficient RDP limited the supply of essential AA`s in the iv duodenum. When the true RDP supplements increased, the duodenal flow of essential AA`s also increased concomitantly, but appeared to level off at the higher RDP levels. Despite the positive quantitative effects of true RDP supplementation on AA supply to the duodenum, the AA profile in the duodenum was unaltered. Consequently, the essential AA profile of duodenal protein of sheep receiving high RDP diets, where microbial protein is the primary source of AA`s in the duodenum, is relatively constant and insensitive to dietary RDP concentration. In the second trial the effects of RDP source (true RDP vs. NPN) on the essential AA profile of duodenal protein on high RDP diets were evaluated by substituting increasing amounts of urea for true RDP in isonitrogenous teatments. Higher NPN increments reduced the daily supply of essential AA`s in the duodenum. In corroboration of the first trial, the AA profile of the duodenal protein was very constant, irrespective of the RDP source. Since microbial protein is the major source of duodenal AA`s on high RDP diets, this study supports the view that microbial protein has a relatively constant AA profile, but microbial protein yield varies according to several rate limiting factors in the rumen. A constant microbial AA profile allows accurate estimates of microbial essential AA supply in the small intestine if microbial protein production and fluid and particulate outflow rates from the rumen can be accurately predicted. This allows the development of more accurate undegradable protein (UDP) supplementation strategies, based on the essential AA requirements of animals. In the second study growing male Merino and Dohne Merino lambs were slaughtered at different weights and body condition scores. The digesta was removed from the stomachs and intestines and every organ or body part were weighed to determine the whole empty body (WEB) composition. The WEB was partitioned into the carcass, internall offal (stomachs, intestines, organs and blood) and external offal (head, feet, skin and wool). No differences were apparent in the proportional weight distribution of similar body components of the same breed at different ages. In a comparison between breeds, the proportional weight contributions of the carcasses from both breeds to the WEB weight were remarkably similar at both slaughtering stages. The Dohne Merino lambs had proportionally larger internal offals and smaller external offals than the Merino lambs at both slaughters. Unless the essential amino acid compositions of the internal and external offals were identical to the carcass, the dissimilarities in weight and protein allocation to these two components within the WEB`s of Merino and Dohne Merino lambs imply a distinct WEB essential AA composition for each breed. The apparent digestibilities of dry matter (DM), crude protein (CP), energy, acid detergent fibre (ADF), neutral detergent fibre (NDF), fat and ash did not differ between Merino and Dohne Merino lambs. Energy retention was also similar for the two breeds, but the Merino lambs retained considerably more N than the Dohne Merino lambs. This may also impact on the respective amino acid requirements of the lambs. Since the Merino lambs utilise N more efficiently, they may have potentially lower essential amino acid requirements to achieve a similar growth rate. The WEB essential AA compositions of growing Merino and Dohne Merino lambs were determined in the third study. Based on the ideal protein concept, the WEB essential AA profile was accepted as representative of the AA requirements for growth. The use of a single body part as a representation of the WEB AA profile was also evaluated. Differences in the proportional weight and protein contribution of the three body components (carcass, internal offal and external offal) of the two breeds strongly suggested that the WEB AA composition of the breeds would differ, because of likely differences in the AA profiles of these components. The essential AA profiles of the carcasses from the two breeds were surprisingly similar. However, the essential AA compositions of the internal offal and external offal differed substantially from each other, as well as from the carcass. In addition, the internal offal and external offals of each breed had characteristic essential AA profiles. Inevitably, the WEB essential AA profiles of Merino and Dohne Merino lambs differed considerably. Only the leucine and phenylalanine concentrations in the WEB`s of Merino and Dohne Merino lambs did not differ. Significant differences in the concentrations of eight essential AA`s implied that the two breeds have different AA requirements for growth. The different AA compositions of the internal and external offal within each breed also illustrated that the use of a single body component, like the carcass, as a predictor of WEB essential AA composition contains considerable inaccuracies. The essential AA index indicated that the duodenal protein, primarily derived from rumen microbes, provided approximately 81 % of the qualitative AA requirements of growing lambs. During periods of sufficient availability of very low-quality forage, as the diet in this study simulated, microbial protein is not able to support maximum growth. The first two limiting AA`s (histidine and methionine) could not even support daily growth rates of 100 g/d. This is very low and stresses the need for effective undegradable AA supplementation under these conditions. Chemical scores identified histidine as the first limiting AA in high RDP diets (predominantly microbial protein), followed by methionine, leucine, arginine and phenylalanine. However, the requirements for histidine and arginine are frequently over estimated and these AA`s should actually be considered semi-essential, which could render methionine, leucine and phenylalanine the first three limiting AA`s to growing lambs receiving high RDP diets. Because of the limitations of static measurement systems for the determination of AA requirements, a more comprehensive evaluation method was introduced for determination of the limiting AA`s in duodenal protein of lambs on high RDP diets, in the fourth study. The fourth study focused on the identification of limiting AA`s to growing lambs being limit-fed a high RDP diet. The diet consisted primarily of soybean hulls, for its’ low rumen UDP content. Microbial protein production was calculated as 13 % of total digestible nutrient intake and complementary AA supplements prepared to simulate the WEB AA profile, determined in the previous study, in the small intestine. To eliminate the influence of the rumen on the AA supplements, the latter were infused into the abomasums via flexible tubing. Each essential AA was in turn removed from the control treatment (simulating the WEB composition) and the effect on N retention measured. When methionine or the branched-chain amino acids (BCAA`s) were removed from the infusate, N retention of the lambs was reduced. Consequently, methionine and at least one of the BCAA`s limited growth performance of young lambs when microbial protein was the predominant source of AA`s. The concomitant increased plasma concentrations of total AA`s when methionine or the BCAA`s were removed from the infusate corroborates the effects on N retention, since it indicates that AA utilisation was reduced when these AA imbalances were introduced. Amino acid imbalances had no effect on apparent DM, organic matter (OM) or NDF digestion, but N digestibility was reduced. The final study verified whether the BCAA’s were co-limiting the growth of lambs, or if any single BCAA was responsible for the limitation. Again the WEB AA profile of growing lambs was simulated in the small intestine via abomasal infusions to lambs receiving a soybean hull-based diet. Leucine, isoleucine and valine were individually or simultaneously removed from the infusate and the impact on N retention measured. On an individual basis valine had the largest negative impact on the efficiency of N utilisation. However, the simultaneous removal of the BCAA`s resulted in the lowest N retention, suggesting that valine might be limiting, but the three BCAA`s are more likely to be co-limiting in diets to growing lambs where microbial protein is the primary source of AA`s. Once again, neither DM, OM or NDF digestibility were affected by the AA imbalances. Nitrogen digestibility was, however, negatively affected by AA imbalances. This project succeeded in establishing the essential AA profile of duodenal protein in sheep receiving high RDP diets. The WEB essential AA compositions of growing lambs from two prominent sheep breeds in South Afica were then determined and the duodenal essential AA profile evaluated against the calculated AA requirements. Finally, the AA`s that limit growth in diets where microbial protein is the predominant source thereof were identified. These results contribute to the current knowledge of AA requirements in growing lambs, and highlight areas for future research, as discussed in the General Conclusion.

M. Tech. (Hospitality and Tourism, Faculty of Human Sciences), Vaal University of Technology. / The primary objective of this study was to formulate a multi-mix, which could supply at least one-third of the daily requirements of primary school children, aged six to 13 years. The secondary objective was to ensure the adherence to the criteria of multi-mix formulation, which included affordability, convenient, palatability, culturally acceptable and cost effective, whilst providing high nutritional value for the specified target group. The nutritional criteria included the Index Nutrient Quality (INQ) and Energy Density (ED) requirements, for a specific target group. This study was conducted in Eatonside, an informal settlement situated in Gauteng. A situational analysis previously conducted in Eatonside (Napier 2003) showed that the children between the ages of six and 13 years, were 17% underweight (weight-for-age -2SD from the reference NCHS median), 12,7% were wasted (BMI-for-age -2SD) and 18% stunted (height-for-age -2SD). With the nutritional requirements of children and the most consumed food list, the multi-mix formulation began. Foods from the Top 20 list (Napier 2003), were combined with the ingredients most common within the households, and vegetable gardens already established . Estimated nutritional values were calculated using the food composition tables of South Africa. The ingredients were prepared and chemically analysed to determine the experimental nutritional value and to assess if the nutritional objectives were being achieved. The multi-mix was then combined with other commonly consumed ingredients to form recipes and sensory evaluated by professionals and the primary school children to assess the acceptability of the multi-mix and recipes. The multi-mix and recipe products were then sent for shelf life testing to assess its storage time at room temperature. The results from the nutritional analyses showed nutrient values to be above 30 percent of the Estimated Average Requirements (EAR). The INQ of the targeted nutrients was above 1,0 and the ED at 3,7kcal/g, which was within the 3,6-4,5 kcal/g requirements. The sensory evaluation for the multi-mix recipes had proved favourable response to snack items with preference for sweet products. The final evaluation session resulted in scores of 83.9 percent preference to the biscuit with the sweet muffin scoring 94.5 percent liking, whilst the savoury muffin at 73.1 percent. The average scores for all three recipes were above 80 percent. The multi-mix had a shelf life of minimum one-month, the biscuit, seven days and muffins, only 24 hours, at room temperature. The objectives of cultural acceptability had been achieved through the positive response from the use of ingredients within the community. The multi-mix had been cost effective as the final cost of R1.55, was within the R2.90 spent per person per day, for all three meals (Oidewage-Theron eta/. 2005). Further studies need to be conducted in order to implement the multi-mix into an intervention within the community to assess the effect on nutritional status. This study, aimed to reduce the underlying cause of malnutrition, food insecurity, by improving the nutritional status of children aged six to 13 years with the strengthening of food intake, through the combination of various scant ingredients, a multi-mix, providing maximum nutritional value with small quantities. An advantage of the multi-mix is a lower cost when compared with tablet supplementation on the market and versatility in relation to various recipes. / Vaal University of Technology National Research Foundation

Thesis (M. Tech. (Food Service Management, Dept. of Hospitality and Tourism))--Vaal Univrsity of Technology. / Inadequate food intake and unhygienic practices are usually associated with poor nutrition practices. Malnutrition stems from poor quality and quantity of foods, but is also contributed to by factors of inadequate maternal and child health care, lack of education and information and insufficient health services. The first phase of this study was to assess the nutritional status and nutritional knowledge of primary school children within a peri-urban community, through the implementation of a situational analysis. Validated 24-hour (hr) recall, food frequency (FFQ), nutrition knowledge and health questionnaires were used to conduct the situational analysis of this community. Parents (n=52) representative of 400 (13.0 percent) children voluntarily agreed to participate and 45 children completed the baseline survey. Results indicated a community faced with poverty as unemployment (60.9 percent) was high, education levels amongst the parents ranging between primary (33.3 percent) and secondary school (54.9 percent). The dietary patterns of the children revealed a carbohydrate-based diet with very few (n=2) consuming a variety of fruit and vegetables. Some nutrition knowledge amongst the children was evident, with a mean 60.2 percent in correct answers for the true/false questions. The children within the community were at risk of becoming stunted, with small numbers having deficiencies in iron. Therefore, it was decided to implement a nutrition education programme (NEP) in the second phase of the study to address malnutrition amongst primary school children. The objectives of the second phase were 1) to implement a NEP amongst the primary school children to assess the impact on nutrition knowledge and dietary practice, and 2) to determine the retention of knowledge after nine months and whether any correlation occurred between knowledge and dietary practices. The school environment was chosen to ensure attendance and create a suitable learning environment to which the children were already accustomed. Two groups, namely experimental (n=82) and control (n=91), were assigned for this study. The control group received no form of nutrition education during the intervention period. The experimental group received nine 45 minute lessons over a period of nine weeks. The nutrition education tools (NETs) were made up of a text and activity book, supplemented by a card and board game. Pre- and post-nutrition intervention knowledge and 24-hr recall questionnaires were completed to assess differences in nutrition knowledge and dietary practices between the two groups. The intervention made a significant impact on the nutrition knowledge of the experimental group, with a 13 percent improvement between pre and post results. Topics which required more emphasis included the importance of variety in the diet, the functions and sources of certain nutrients, and the classification of certain food groups and the daily serving requirements. In the long-term evaluation, nutrition knowledge was retained and related to topics of the inclusion of milk and fat on a daily basis, the serving size of starch, dairy products and fruit and vegetables, and the classification of low-fat snack items. Retention of knowledge was poor for the source of vitamin C. A few changes were made in the dietary choices of the children after the intervention, with the inclusion of more carbohydrates and one fruit. During the long-term evaluation, the children included more protein sources, but carbohydrates remained dominant within the Top 20 list. The energy distribution in the long term changed towards more energy being supplied from protein (15.6 percent) and fat (34.4 percent), compared with post results of 13.7 and 25.8 percent respectively. The multivariate analysis revealed a significant correlation between the protein intake of the Top 20 list and the question relating to the number of eggs (p=0.00) to be consumed daily, as well as the link between vitamin C (p=0.00) and fruit and vegetable intake. A limitation is that a small number of children (n=27) could not complete the post test, with another 34 children not present to complete the long-term evaluation. The children had very little control of the dietary patterns as their mothers were primarily responsible for food procurement, preparation and feeding. A recommendation is to commence the intervention in the beginning of the year and to consider a co-ordinated approach with parents to encourage dietary changes. / Vaal University of Technology and SANPAD

Graduation date: 1997