The South African mariculture industry is developing the rearing technology of indigenous fish species. Dusky kob (Argyrosomus japonicus) has high-quality flesh and a good market demand. Research is needed to determine the environmental requirements under which growth of dusky kob is optimised. This study assessed the effect of temperature, light intensity, feeding frequency and stocking density, respectively, on growth, feed conversion ratio (FCR) and survival of juvenile dusky kob within a weight range of 10-60 g fish⁻¹) in a series of four growth trials. The effect of temperature on growth and FCR was assessed at 14 temperatures from 17 to 28°C. The temperature for best growth was estimated to be 25.3 °C, while 21.4 °C was the temperature at which the best FCR was achieved. A growth trial testing the effect of light intensity on growth showed that light intensity did not affect growth in the range of 23 – 315 lx. Fish fed a restricted ration of 3.6% body weight per day (chapter 2) or 3.41% body weight per day (chapter 4) had a better FCR than fish fed to satiation. A trial to assess the effect of feeding frequency on growth and FCR showed that fish fed both two or three times daily grew better than those fed once daily. FCR was best in fish that were fed once or twice daily. Preliminary analysis of the results from a stocking density trial showed that stocking density in the range of 10 – 50 kg m⁻³ did not affect growth of juvenile dusky kob. It is recommended to culture dusky kob at a temperature of 25.3 - 21.4 °C at stocking densities up 50 kg m⁻³ to maximise growth. However, a study is needed to determine the environmental conditions needed to maximise profit under commercial conditions. The results allow the South African industry the opportunity to assess the culture potential of this species. In addition, the results will help develop protocols that can be used in other South African candidate aquaculture species such as silver kob, yellowtail, white-stumpnose and sole.

Animals are restricted in their diets by several factors, most notably the availability and quality of resources. Variation in resource availability causes herbivores to shift their diets seasonally and spatially. Elephants (Loxodonta africana), are known to have extensive impacts on plant communities, altering ecosystem functioning and causing a decline in biodiversity. In enclosed areas, these impacts are increased leading to a decline in resource availability and presumably resource quality. In the Addo Elephant National Park, the Main Camp section has a history of high elephant impacts and therefore reduced resource availability. Whereas, the recently added Colchester section has greater resource availability, due to the absence of elephants in this section since the fencing of the Park. This study investigated the changes in diet (diet breadth, preference and diet quality) of elephants due to an increase in resource availability. Three alternative hypotheses were contrasted: 1) elephants as generalist foragers, 2) elephants as optimal foragers, or 3) elephants learning foraging behaviour. Using microhistological analysis, the diets of elephants were described over five sampling periods (August 2010 – February 2014) in both sections. Forage availability was estimated using a modified line-intercept method, and was used to determine changes in preference by relating forage availability to use. In the Colchester section the diet breadth of elephants increased, and was coupled with a high initial variation between the diets of elephants, which decreased in subsequent sampling periods. This supported the elephants learning foraging behaviour hypothesis. However, there was no increase in diet preference by elephants in the Colchester section, which supported the elephants as generalist foragers hypothesis. There was also no difference in the diet quality of elephants in the Main Camp and Colchester sections, which did not support any of the three hypotheses. The elephants learning foraging behaviour hypothesis is proposed to be the link between the alternate two hypotheses, and given enough time, either of the two could be supported. The lack of difference in preference and diet quality between elephants in the Main Camp and Colchester sections is hypothesised to be due to the population level (not measured for individuals) at which these were measured. Microhistological analysis of faeces was used to describe the diet of elephants, which was compared to the diet described by DNA metabarcoding. Microhistological analysis is a traditional, favoured technique used in describing the diet of wild herbivores, whereas DNA metabarcoding is a relatively new and untested technique. These two techniques have not yet been compared in the diet of megaherbivores. Results indicated that microhistological analysis identified significantly more grass in the diet of elephants, than DNA metabarcoding did, which was expected as previous studies also found overestimation of grasses. Microhistological analysis identified more plant families in the diet of elephants, than DNA metabarcoding. Most of the differences between the two techniques can be attributed to the difference in taxonomic resolution, which was due to the lack of a complete reference collection for DNA metabarcoding. Although either of the two techniques can be used to describe the diet of elephants, the most reliable results would be obtained when using both techniques. The findings of this study suggest that due to the high initial variation between the diets of elephants, with an increase in resource availability, the impacts will also initially be highly varied. This suggests that identifying plant species to monitor elephants impacts initially will be difficult. However, important plant species, or those known to be vulnerable to elephants impacts should be carefully monitored initially and monitoring should not only occur annually, but also seasonally.

The aim of this study was to explore and describe the body fatness and associated selected health risk factors among 10 to 12 year old adolescents attending schools in Port Elizabeth. Therefore the objectives of the study were to determine the following for the participants: • Level of fatness: weight, height, waist circumference, maximum hip circumference and skinfolds; • Fat intake; • Level of physical activity involvement (IPAQ). To achieve the aim and objectives of this study, the literature pertaining to Childhood Obesity and the possible effects thereof, were reviewed. Both an ex post facto quasi experimental and randomized one-group posttest only designs were used to describe the level of fatness and to identify the incidence of overweight and obesity among adolescents aged 10 to 12 years attending schools in Port Elizabeth. The test battery included anthropometric measurements that were identified from the literature as the factors most important to categorise body fatness such as weight, height, circumferences and skinfolds to determine the level of fatness of the participants. A 21-item Fat Measure for Dietary Intake and International Physical Activity Questionnaire were administered to determine the levels of fat intake and physical activity. Three hundred (300) adolescents were assessed of which 143 were male and 157 were female. In terms of socioeconomic status, 71.3 percent were from the ‘less poor’ quintile schools and 28.7 percent were from the ‘more poor’ quintile schools. The results obtained from the evaluation of the samples were compared in terms of their descriptive statistics and the differences were tested for statistical and practical significance. The results from the study showed that 26.7 percent of the participants were overweight and 14.7 percent were obese according to their skinfold measurements. In terms of body mass index, 79.7 percent of the participants were overweight and 14.3 percent were obese. These results are far higher than majority of the studies included. Physical activity indicated a reduction in body fatness and the most physically active participants were obese. Lastly, body fat percentage and body mass index are very closely related.

Submitted in fulfillment of the requirements of the Master of Applied Science in Food and Nutrition, Durban University of Technology, Durban, South Africa, 2016. / Introduction: South Africa, like many other developing countries, is challenged by malnutrition among children. Globally, the nutritional status of children is a cause for great concern. The nutritional shift towards diets laden with sugar, fat and salt contribute towards the burden of non-communicable diseases (NCDs). Snacking plays a pivotal role in the diets of children; however, the consumption of unhealthy snacks or ‘junk’ food poses a serious risk to a child’s nutritional well-being. Moringa oleifera was selected for snack food development in this study, as this plant is a significant source of nutrients. Aim: The aim of this study was to determine the snacking preferences of children (grades 4-7 in four schools in Verulam, KwaZulu-Natal (KZN), South Africa, in order to develop a sensory acceptable snack enhanced with Moringa oleifera. Methodology: Two hundred primary school children between grades 4-7 were selected through stratified random sampling of schools in Verulam, KZN, South Africa through informed consent to participate in this study. In addition, ten parents/caregivers formed part of the preliminary study to determine the snacking habits of children in the selected grades. This information was reported in the form of themes. A Snack Food Frequency Questionnaire (SFFQ) was administered to children for the sole purpose of determining snacking preferences. This was supplemented by an observational study to assist with identifying the most frequent tuck shop purchases. Thereafter, once the top three snack items were identified, the main study continued with the development of a healthy snack, through three cooking trials before an appropriate product was developed. The final product was made using three different amounts of dried Moringa leaves (1g Moringa, 2g Moringa and 3g Moringa per 22g portion) in a maize chip. The developed product was then subjected to nutrient testing in order to determine the vitamin A, zinc, iron and calcium content of the three different variants. The carbohydrate, fat, energy and sodium values were calculated by using the Association of Official Analytical Chemists (AOAC) International standardised methods. Microbiological and shelf life testing were also conducted to ensure the chips were safe for human consumption. Consumer acceptance sensory evaluation was conducted among the children (n=100) to determine the most preferred amount of Moringa leaf in the snack food item (either 1g of Moringa or 2g Moringa). To determine which of the two variants (sample 1 containing 1g of Moringa and sample 2 containing 2g Moringa) was preferred, two variants of the product were sampled by the participants; samples were coded in order to prevent bias. Results: Overall, the results from the focus group study revealed that children consumed snacks frequently and were given money regularly to purchase snack items from the school tuck shop. Price was a trend noted in factors that affect snack selection. The parents/caregivers responded positively towards purchasing a snack that was nutrient-rich. However, it was noted that the price should be reasonable. Results of the SFFQ indicated that the most popular snack items were chips, cold drinks and sweets; therefore these items were reviewed to determine the most viable option for further development. It was decided by the researcher and the supervisor that chips would be the snack item enhanced with three different amounts of Moringa. The consumer acceptance sensory evaluation comprised two chip samples (123 and ABC). The results of the consumer acceptance sensory evaluation showed that sample ABC (2g Moringa/22g serving) was preferred to sample 123 (1g Moringa/22g serving) for most of the sensory attributes (taste and texture). The Moringa chips (both samples) contain almost half the amount of sodium (52.8mg) when compared to a popular corn chip brand (100mg). Moringa chips contained almost less than 1 gram of fat compared to 8 grams of fat found in the corn chips children usually consume. One portion (22g) of the Moringa chips contributes a significant amount of non-haem iron (57.89%, 48.25% and 35.61% for sample 1, 2 and 3 respectively) for females aged between 9-13 years old. Conclusion: Moringa chips (2g/22g serving) received a positive response from children in the sample population. The use of indigenous plants such as Moringa, could be beneficial in food based strategies aimed at addressing malnutrition. Recommendations: This study concluded that food based strategies such as the development of the Moringa chips, should be considered as a means to create a healthy option for children in low socio-economic schools. / M

Submitted in fuliillment of the requirements for the degree of Master of Education in the Department of Comparative and Science Education ofthe Faculty of Education at the University of Zululand, South Africa, 2004. / The case study explored the knowledge and understanding of nutritional issues by Mohlabetsi Senior Secondary School grade 12 learners. The information was collected through a test that was administered to the learners under test conditions. The test consisted of multiple choice type questions, short answer questions and definition of terms. Analysis of the results were limited to multiple choices questions because they cover a wide portion of the syllabus, and the definition of terms because they could help the researcher determine whether the learners are learning with understanding or not. The second tool used in the research was a hands on-activity where the subjects determined their Body Metabolic Indices to deterrnine their nutritional status. The results of the study showed that the learners harbour misconceptions about nutrition issues. For instance, the subjects had problems in defining a list of given terms relating to types of nutrition. The terms referred to different options of feeding. In defining terms the subjects combined words they had heard or used phrases which did not respond to the question asked or did not make sense. Language problems were prominent in the answers the subjects gave. One example was for a subject to define malnutrition as "the impairment of the diet from the body". Only 35% of the students obtained marks above 50 in the multiple choice questions. The low scores could also be attributed to poor comprehension of the language of instructions that is not their mother tongue. In terms of the nutritional status of the subjects, weight problems already exist in some of them. Because of the highly active lives of teenagers one does not anticipate weight problems among youth. There were 14.54% students with BMI above 30, that is, subjects that were overmass. Other subjects (9.10%) were obese. If these students do not loose mass and carry their present mass to adulthood, they are at risk. These subjects are an insurance liability and likely candidates for diabetes, hypertension and strokes. That is why nutrition education should be a lite learning process. A few subjects (10.90%) were underweight as a result of inadequate food security in their families. It was good that 65.45% of the subjects had normal weight which they were advised to maintain, particularly because obesity is becoming an epidemic among Black Africans. Recommendation from the study are to the effect that teachers at Mohiabetsi Senior Secondary school need to encourage learners to speak English The poor English language expression of the subjects in answering questions showed very poor competence in using the medium of instruction to communicate. It was also difficult to determine whether subjects got poor marks out of ignorance or from an inability to express, what they know, in a foreign language. A second recommendation was that it is important to teach learners how to answer questions in complete sentences that makes sense. The third and last recommendation was that all learners need to be empowered with skills to assess their nutritional status in order to stay healthy and avoid future pain.

The purpose of the study is to illustrate the challenge of providing sufficient micronutrients to the inhabitants of South Africa. Traditional foods have therefore been identified as one of the strategies that can be employed to lessen the problem in the community of Nompumelelo, Eastern Cape province and the research involves the availability of traditional foods in this area. It is common practice for most rural people in South Africa to include traditional foods in their diets and Nompumelelo is no exception. Hence, the study also explores the rural-urban linkage of the use of traditional foods by peri-urban households in the Xhosa community of Nompumelelo. It could be argued that the traditional foods produced in this community are accessible to the whole community, resulting in greater food sustainability. It is a fact that many communities are of the opinion that food is not readily available, not realising that traditional foods are locally available. / Human Ecology / M.A. (Human Ecology)

Baby spinach is a relatively new crop in South Africa with both commercial significance and reputed health benefits. It is known to assist in combating degenerative conditions associated with ageing, such as heart disease, cardiovascular disease, Alzheimer’s disease, cataracts and several forms of cancer. Three parallel NPK trials were conducted to investigate the effects of nitrogen (N), phosphorus (P) and potassium (K) on the growth and development of baby spinach. N and P treatments were arranged as (0, 45, 75, 105, 120 kg.ha -1 N and P), and K treatments were arranged as (0, 63, 85, 127, 148 kg.ha -1) in a randomised complete block designed with four replicates. Results showed that yield, dry matter, chlorophyll content and Leaf Area Index (LAI) were significantly increased by increasing the N application, while K had a significant effect on the LAI but not on yield, dry matter, chlorophyll content or stomatal conductance. Nitrogen treatments quadrupled fresh yield, dry matter and chlorophyll content, reaching maximum impact at 75 kg.ha-1 N. Phosphorus application showed significantly increased yields, dry matter and chlorophyll content, reaching maximum impact at 75 kg.ha-1 P. Therefore, to achieve optimum growth with N and P, 75 kg.ha-1 is recommended. The optimum rates of N, P and K were then used to formulate a NPK combined trial which was arranged as 0, 30:30:40, 45:45:60, 60:60:70, 75:75:90 kg.ha-1 in a randomised complete block design with three replicates. The results showed that maximum impact on yield, chlorophyll content, fresh and dry matter was achieved when combined NPK was applied at 45:45:60 / Agriculture and  Animal Health / M. Sc. (Agriculture)

Degradation kinetics of carbohydrate fraction of commercial concentrate feeds for weaned calves, heifers, lactating and dry dairy cattle / Variations in composition and disappearance of nutrients in dairy cattle feeds are dictated by ingredients, methods of processing, storage while milk production levels depend on the animal, environmental factors and largely on pools of available carbohydrates, proteins, vitamins and minerals in the concentrate feeds. There is a wide variety of concentrates for dairy cattle on the formal and informal markets and dairy farmers need to be astute in selecting feeds appropriate for specific production periods and animals to sustain their businesses. Composition of nutrients displayed on concentrate containers is however inadequate for in-depth assessment of products. This study determined nutrient composition, rumen dry matter disappearance and microbial colonization on residual substrate on commercial concentrate feeds and simulated total mixed rations for dairy calves, heifers, lactating and dry cows based on common feeding guidelines. Equivalent feeds for each herd group were obtained from three suppliers in the formal markets in Gauteng province of South Africa, making a total of twelve. An analysis of the data on container labels for the herd groups displayed similar feed values, as also reflected on the recommendation Tables of Act 36: Feeds and Fertilizer bill 1947 of South Africa. / Agriculture, Animal Health and Human Ecology / M.Sc. (Agriculture)

Submitted in fulfillment of the requirements for the Degree Magister Technologiae: Consumer Science Food and Nutrition, Durban University of Technology, 2014. / Introduction: Dietary diversity is an indicator of access and measurement of household food security as it relates to income, location and seasonality. Dietary diversity is measured by physically counting the number of individual foods as well as food groups consumed over a given reference period. When dietary diversity is accurately measured, nutrient adequacy will be easily predicted. In order to measure dietary diversity accurately, it is important to determine household food security. Insufficient food and resources often result in food insecurity which leads to little or no dietary diversity. Poor populations suffer most from achieving dietary diversity because they consume a standard diet based on starchy staple food with limited fruits and vegetables resulting in multiple nutrient deficiencies. Rural communities rely on seasonal food variety in order to obtain fruits and vegetables needed by the body to limit nutrient deficiencies. Some seasons are more productive than others. Rural communities also use various coping strategies to deal with food insecurity in all four seasons. High levels of unemployment as well as a lack of nutrition education results in most rural households unable to cater for dietary diversity. Aim: The aim of the study is to determine the effect of seasonal food variety, dietary diversity and nutrient adequacy on the nutritional status of women in rural areas. Method: A hundred women in this community were weighed and measured and BMI determined and classified according to the WHO cut-off points for BMI. Waist circumference was measured in order to determine the waist-to-height ratio indication risk of metabolic syndrome. Twenty four hour recall questionnaires were used to determine actual intake compared to dietary reference intake (DRIs). Food Frequency Questionnaires for a period of seven days were completed captured and analysed using the SPSS version for descriptive statistics in order to determine food diversity. Coping strategies were determined by Focus Group interviews with community members in order to identify the various strategies used in time of food shortages. The severity of these strategies was determined by the community. Seasonal food consumption patterns and dietary intake behaviour were assessed over the four seasons. The highest frequency score (7) x severity weight (1-4) x10 strategies = maximum score of 140. Thus the higher the score the more food insecure the community is. Results: Food production from crops differs in different seasons. Food insecurity is high in summer and autumn due to a low number of food items harvested from crops. The community cope less in summer and autumn due to less crops available. The community is more food insecure in spring and winter due to the high number of food items harvested from crops. The community cope better in winter and spring due to the high level of available crops. Anthropometric measurements indicated that 41.2% of women between 31 and 50 and 49% of women between 51 and 70 years of age had a BMI of 30 and above. About 44% of total women are obese and 29% are pre obese. Only 26% had a normal weight. The 24 hour recall analysis indicates that the high level of obesity is due to the fact that a high number of participants consume large amount of carbohydrates every day. Conclusion: Overall results in this study indicated that this rural community is food insecure, on a higher level during summer and autumn, which leads to the consumption of undiversified diets. The women are malnourished and obese with a risk of metabolic syndrome. The information obtained in this study can be used to formulate strategies to develop interventions that can be used to access sufficient food in rural area in order to improve food insecurity, dietary diversity and, therefore, nutrient adequacy.

Submitted in fulfilment of the requirements for the degree Master of Applied Science in Food and Nutrition, Durban University of Technology, 2015. / Introduction: According to the American Dietetic Association, Child care facilities (CCFs) play an essential role in the nutritional status of children as children typically spend 4-8 hours a day at a facility. As a result, the meals should provide at least 50 – 60% of daily nutritional requirements. Worldwide CCF feeding has been found to be nutritionally inadequate as energy and most micronutrient requirements are not met by the meals provided, due to the lack of nutrition knowledge of the caregivers. Studies have shown that with appropriate training there has been improvement in nutritional standards. Aim: The aim of this study was to analyse the nutritional adequacy of menus offered; and to determine the nutritional status of children aged two to five years old in registered child care facilities in the Inanda area. Methodology: CCFs (n=10) in the Inanda area were randomly selected from multiple options to participate in the study. This study was conducted on children (boys (n= 91) and girls (n=109)) of ages two to five years old. Trained fieldworkers and teachers assisted in interviewing parents to complete the socio-demographic questionnaire. The researcher gathered menus and recipes for analysis, using Foodfinder Version 3 Software. The researcher also conducted plate-waste studies to determine consumption patterns during CCF meal times. Anthropometric measurements for weight and height were collected. In order to establish BMI-for-age and height-for-age, the WHO Anthro Software and WHO AnthroPlus Software were used. Ten food handlers (FHs) were interviewed by the researcher on food preparation and serving. Results: Most children (79.40%) originate from extended families that are female-headed. The highest form of education attained by most caregivers in the sample is standard 10 (47.74%) and 45.73% are unemployed. Of the 54.27% employed, 64.71% are informally employed. Most respondents (72.87%) are living on a total household income of less than R2500. The anthropometric results of the children show very low prevalence of severe stunting (1.74%) and stunting (5.42%). Less than halve (34.48%) of the children were at a possible risk of being overweight, 13.79% were overweight and 2.46% obese. The top 20 foods served in CCFs in Inanda were cereal-based staples of rice and maize meal more frequently than meat, dairy products and fruit and vegetables – all served far less frequently. All the CCFs did not meet the 60% of daily requirements for energy, fibre, calcium and vitamin C in foods served. The CCFs have well-equipped, designated kitchens for food storage, preparation, serving and good hygiene practices. Conclusion: Meals served to two to five year olds in registered CCFs in the Inanda area are nutritionally inadequate as most facilities do not contain 60% of the daily nutrient requirements from both daily meals served. Recommendations: CCF owners and Food handlers should receive proper training and retraining on food safety and hygiene and menu planning. The government should increase the subsidy to CCFs in order to meet the nutritional needs of children in order to aid in the alleviation of under-nutrition.