An understanding of species specific water quality requirements is essential for efficient production of aquaculture products, an aspect not well documented for the land-based culture of the South African abalone, Haliotis midae. In order for the industry to remain competitive in international markets, efficient use of water supplies and the development of water reuse technology is needed. This study assessed the changes in water quality between tanks in a tiered serial-use raceway in relation to accumulated biomass and water flow and estimated the flow index (FI) (L h⁻¹ kg⁻¹) at which growth becomes significantly affected. The effect of dietary protein level, supplementation of pure oxygen and addition of sodium hydroxide (NaOH⁻) on water quality and fundamental production parameters in the serial-use raceways was also assessed. The serial-use raceways were used as a tool to create a range of water quality conditions at which the growth, feed conversion ratio (FCR) and condition factor (CF) of "cocktail" size (60 – 70 mm) H. midae could be monitored. The metabolic activity of the abalone resulted in a deterioration in water quality between tanks in series. pH (r² = 0.99; p < 0.001) and dissolved oxygen concentration (r² = 0.99; p < 0.001) were positively correlated with flow index (pH = 7.38 FI°·°² ; dissolved oxygen = 6.92 FI°·°⁴), while free ammonia nitrogen (FAN) (r² = 0.99, p < 0.001) and nitrite (NO²⁻ - N) (r² = 0.93, p < 0.001) were negatively correlated with flow index (FAN = 8.02 FI⁻°·⁷¹). Nitrite concentrations increased over time indicating colonisation of Nitrosomonas bacteria on the basket surfaces. A flow index of 7.2 – 9.0 L h⁻¹ kg⁻¹ was estimated as the minimum to avoid significant reductions in weight and shell length gain and increases in FCR values. Total ammonia nitrogen (TAN) and FAN concentrations were significantly correlated to dietary protein (P) (t = 6.63, p < 0.0001 and t = 6.41, p < 0.0001, respectively) and flow index (t = 5.42, p < 0.0001 and t = 3.9, p < 0.0002, respectively) and could be estimated using the models TAN = 9.73 P – 110.3 log (FI), and FAN = 0.132 P – 1.10 log (FI). Mean FAN concentrations were 67 and 41 % lower in tanks fed a diet containing 22 and 26 % protein respectively, when compared to tanks fed a 33 % protein diet. Supplementation with pure oxygen (103 ± 8 % saturation) improved shell length gain (t = 3.45, p = 0.026) in abalone exposed to high FAN (2.43 ± 1.1 μg L⁻¹) and low pH (7.6 ± 0.13), relative to a treatment with no oxygen supplementation (92 ± 6 % saturation). Addition of a sodium hydroxide solution resulted in elevated mean pH in treatment raceways when compared to control raceways. The increased pH resulted in significantly higher weight gain (g abalone⁻¹) (F₁·₁₂ = 4.51; p = 0.055) and shell length gain (mm abalone⁻¹) (F₁·₁₂ = 4.56; p = 0.054) at an α-error level of < 5.5 %. In two trials, weight gain and shell length gain were significantly correlated to pH (p < 0.001), and multiple regression of pH, dissolved oxygen and FAN consistently revealed pH to be the best predictor of growth. It is therefore suggested that decreasing pH is the first limiting water quality variable for abalone in serial-use raceways. As a decrease in water pH is linked to respiration by the abalone and subsequent increase in dissolved carbon dioxide (CO₂) concentration, future studies should examine the effects of CO₂ on H. midae metabolic rate, calcification rate and health. The results of this study will contribute toward our understanding of the specific water quality requirements for H. midae in commercial aquaculture systems, and influence the design and management procedures for abalone water reuse systems.

The re-introduction of cheetah onto small reserves in the Eastern Cape Province has created the opportunity to study this species in an environment (Valley Bushveld) in which it has not previously been studied and which is quite different from the less wooded habitats in which previous studies have occurred. Thus the aim of this study is to add to the growing number of studies of cheetah in more wooded habitats and to contribute a better understanding of the level of specialization or adaptability in space use, habitat selection, diet and hunting behaviour that the cheetah possesses. The research was conducted on Kwandwe Private Game Reserve from February 2003 to August 2004. Direct observations, scat analysis and continuous observations were used to avoid bias towards large sized prey found when only using direct observations to study diet. The cheetah killed 15 species and four of the five most important prey species (kudu, springbok, grey duiker and bushbuck) were hunted according to their abundance on the reserve, while impala, the fifth most important prey species, was avoided (i.e. preference index less than one) by the cheetah. The cheetah’s main prey was medium sized ungulates, although the three male coalition killed larger prey than females and females with cubs. The daily food intake per cheetah per day was calculated to range from 5.3kg/cheetah/day for the coalition to 8kg/cheetah/day for a solitary female. Home range areas ranged from 11.1 km² for female cheetah with cubs in a den to 65.6 km² for single female cheetah and core areas ranged from 6 km² for the three male coalition to 26.5 km² for independent cubs. Habitat selection by cheetah on Kwandwe varied between the social groups depending on their susceptibility to predation by lions, their need for cover and need for water, and was similar to what has been previously reported. The home range of the coalition incorporated the most open vegetation type (karroid shrubland) with surrounding denser vegetation, while females occupied areas of denser vegetation. Activity patterns and hunting behaviour varied between different cheetah social groups with female cheetah being more active during day light hours compared to males which made 38% of their kills after dark. The average chase distances for the various cheetah groups varied considerably, and the chase distance for successful hunts was longer than for unsuccessful for all groups except single female cheetah. The percentage of kills’ kleptoparasitised on Kwandwe was very low compared to other studies possibly due to the low density of direct competitors, which in turn lead to longer mean kill retention times. These results suggest that cheetah are more adaptable than previously thought and this adaptability may have important implications for their conservation.

The nyala on Buffelsdrift Private Game Reserve were found to be mainly browsers and made little use of grass during the study period. Browse contributed 87.8 percent to the annual diet, while grass contributed 12.2 percent. Only six species formed > 5 percent of the annual diet. Of these six only three species formed > 10 percent. They are the shrubs Acacia karroo, Pappea capensis and Grewia robusta. These were followed by the shrub Portulacaria afra, the dwarf shrub Zygophyllum lichtensteinianum and the grass Cynodon dactylon all contributing between 5 - 10 percent. There were definite seasonal dietary shifts with preference to different plant species. The shift takes place between the wet seasons (winter and spring) and the dry season (summer). Herbaceous species such as Cynodon dactylon and Erharta calycina were favoured in the winter/wet season. Shrubs such as P. capensis, P. afra and dwarf shrubs such as Limeum aethiopicum and Z. lichtensteinianum were favoured during the spring/wet and summer/dry seasons. Nyala habitat use in BPGR differed significantly from expected use when taking the relative area of habitats into consideration. However nyala did not display signififcantly different habitat preferences between seasons. Male and female nyala displayed differences in foraging behaviour at the plant form, plant species and habitat scale. Males preferred a greater proportion of shrubs and females a greater proportion of dwarf shrubs. Males preferred the shrubs Pappea capensis and Portulacaria afra the most and females preferred the dwarf shrubs Limeum aethiopicum and Zygophyllum lichtensteinianum the most. Plant species site availability varied significantly between the sexes, indicating that males and females selected different feeding paths. The difference in their feeding strategy appears to be related to the selection of plants that best satisfy the nutrient requirements of each sex. These findings are in agreement with the results from earlier studies on nyala sexual dimorphism. At the habitat scale females selected more for open dwarf shrubland and males more for densely vegetated habitats. This appears to be as a result of males attempting to maximize their foraging opportunities by selecting areas that offer food in greater quantities. Nyala in BPGR appear to co-exist with kudu and eland through spatial resource partitioning. This is suggested to be due to the influence of body size-gut size relationships on forage selectivity.

Effects of Acacia karroo supplementation on meat quality of Xhosa Lop-Eared goats The objective of the study was to determine the effects of A. karroo supplementation on the quality of meat from Xhosa lop-eared goats. Eighteen castrated 4-month-old Xhosa lop-eared male kids were kept at the University of Fort Hare Farm until slaughter. At the beginning of the experiment the goats had a mean body weight of 13.5 ± 0.31 kg (mean ± S.E.) and a mean body condition score (BCS) of 3.3 ± 0.16 (mean ± S.E.). From birth until weaning the kids were kept on natural pastures with their mothers. After weaning the goats were housed in an open sided barn for a period of 60 days, and were fed 500 g/head/day of Medicago sativa hay covering their maintenance and growth needs. For the purpose of the experiment, the goats were randomly divided into two balanced treatment groups of nine goats each, supplemented group (AK) and non-supplemented group (NS). The supplemented group received an additional 200g per head per day of fresh A. karroo leaves collected each day for two months. Supplementary feed was given to the goats individually in feeding troughs. The kids were slaughtered at 60 days old and samples for meat quality assessment were taken from the Longistimus dorsi muscle. The effect of A. karroo supplementation on meat quality measurements such as ultimate pH, colour and cooking losses of meat from indigenous Xhosa lop-eared goats were determined. The effect of A. karroo supplementation on the consumer sensory characteristic scores of the meat from the indigenous Xhosa lop-eared breed was also determined. There was a significant effect of the A. karroo supplementation on the meat quality measurements except for L* and a* colour coordinates. Meat from the A. karroo supplemented goats had lower pH and cooking loss scores than that of the non-supplemented goats. Acacia karroo supplementation improves meat tenderness and juiciness. There were no significant effects of A. karroo supplementation on the flavour and off- iv flavours of the meat from the supplemented goats. However, thermal preparation and consumer background had a significant effect on the meat sensory characteristics. The cooked meat had significantly higher sensory scores than the roasted meat. Female consumers reported higher sensory scores than male consumers. Consumers of different tribes and ages also reported significantly different sensory scores of meat from indigenous Xhosa lop-eared goats. Therefore, this study indicated that A. karroo supplementation can be fed to the Xhosa lop-eared goats to improve their meat quality.

PhDPH / Department of Public Health / The benefits of breastfeeding, particularly exclusive breastfeeding, are well recognized. It can reduce the risk of mortality related to malnutrition, otitis media and respiratory infection. Breastfeeding may also decrease the risk of obesity in later life for infants who have been breastfed for more than six months. Besides, breastfeeding improves cognition, and children who have been breastfed show higher intelligence quotient test scores and improved school performance. In addition, long-period breastfeeding is associated with a reduced risk of breast cancer and ovarian cancer for mothers. The World Health Organization and United Nations International Children’s Emergency Fund recommended exclusive breastfeeding for six months and breastfeeding to two years and beyond. However, this study showed that only 27% of children under six months have had been exclusively breastfed. In this situation, an intervention programme was required. The aim of this study was to develop an intervention programme to promote exclusive breastfeeding strategies in Limpopo Province. Intervention mapping was used to guide the development of a programme. A convergent, parallel mixed-method was used wherein qualitative and quantitative data were collected and analysed concurrently. A qualitative approach was used to assess the implementation of exclusive breastfeeding and to explore challenges experienced by health care workers in the implementation of exclusive breastfeeding in Limpopo Province. This was carried out by means of in-depth interviews with 30 professional nurses. Trustworthiness was ensured through credibility, confirmability, dependability and transferability. A quantitative approach was used to determine the factors that influence exclusive breastfeeding. Reliability and validity of the instrument was ensured through extensive literature review and test-retest methodology. Questionnaires were distributed to 400 respondents. Tesch’s eight steps of data analysis was used to analyse qualitative data. The Statistical Package for the Social Sciences, version 26, was used to analyse the quantitative data. The results were merged, and the interpretation discussed. Five higher-order themes emerged from quantitative data analysis. The themes emerged from qualitative data were confirmed by the findings from statistical data, thus merging both qualitative and quantitative data. Findings were presented to the stakeholders, managers and dieticians and their inputs further confirmed and supported the findings. The findings informed the development of an intervention programme. The intervention comprises of the three components, training of community health workers, healths talks focusing on lactating mothers and health talks focusing on families and community. The developed intervention was validated by the stakeholders and the results were analysed through simple descriptive statistics where the data were summarized using frequency distributions and graphic representations. The results revealed that the programme was feasible, compatible and applicable to current practice. Recommendations were made and topics for further research were also suggested. / NRF

BScnut / Department of Nutrition

A prospective longitudinal study was carried out to establish the relationship between growth, development and social milieu in Coloured pre-school children in Cape Town. This population was selected because, on the basis of previous studies, a wide range of nutritional status as well as a spectrum of socio-economic conditions were known to exist. A pilot study was conducted to establish the feasibility of obtaining information about factors to be included in the study as well as to determine the most suitable sampling methods. A cohort of 1 000 consecutive Coloured infants born in the Cape Town municipal area and notified to the Cape Town City Council was identified. A random sample of 187 was selected from the cohort for long-term study. Anthropometric data were documented from birth until 5 years and compared to the NCHS reference values. Developmental data consisted of milestones recorded during infancy, language assessment on the Reynell Language Scale at 2½ years carried out by the Logopaedics Department, University of Cape Town, and at 5 years, a specially constructed developmental assessment designed to assess gross motor function, fine motor development including visuo-motor skills and language, both comprehension and expression as well as basic colour and number concepts. Social data were collected during home visits by two experienced, full-time research social workers, who were both integrally involved in the planning of the study. At birth infants were relatively light and short for gestational age. Size at birth correlated with social class. A rapid post-natal weight gain rendered them relatively overweight between 3 and 6 months. Thereafter they again became lighter and shorter than the NCHS reference values and this persisted during the pre-school period. Mother's weight was related to weight at birth, 12 months and 30 months. The genetic influence on growth was reflected in a correlation between parental height and child's length from 12 months onwards. Environmental influences as assessed by social class by occupational grading of the breadwinner, income and family stability were also correlated with growth from 12 months onwards. Infant development as indicated by milestones was very similar to internationally reported studies. Motor development was not associated with social class by occupational grading of the breadwinner but with father's education, mother's personality and family stability. It was also highly correlated with growth during infancy. Early language milestones were associated with the child's micro-environment as indicated by marital status, family unit, setting and stability. Language development at 30 months reflected a general lag in verbal skills and was correlated with parental education and family stability. At five years there was a good correlation between growth, development and social milieu, although the social variables accounted for far more of the variation in development than did growth. Social class by occupation grading of the breadwinner and income reflected the general socio-economic status and there was a good cross-correlation between the social variables. Approximately one third of the families lived in a middle cl ass environment. However, poor maternal education, low incomes and over-crowding were prevalent and must constitute risk factors in child rearing. Sixty five percent of the mothers were not educated further than primary school level and over half of the families were living below an effective minimum level of income. Similarly, over half the families lived in grossly overcrowded conditions. In conclusion, therefore, during infancy developmental milestones were similar to those reported in the literature. Later, however, there was a fall-off in development and this coincided with a greater association with social circumstances. Just prior to school entry social factors far outweighed growth indices as predictors of developmental variation. Social stability of the family a composite evaluation based on a number of social characteristics, was most consistently associated with development. The implications for intervention are that this would need to be broad based and aimed at improving incomes, housing, family cohesion and child centredness and eliminating social pathology. Such intervention would require a concerted effort from a variety of sources which should include administrators, community workers and health professionals.

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 fulfilment of the requirements for the degree Master of Applied Science in Food and Nutrition, Durban University of Technology, 2015. / Objective: To determine the contribution of packed school lunches to the daily food intake of girls and boys in two Primary Schools in East London. Methods: The study was conducted among 199 girls and boys aged 9-13 years. Three 24-Hour recalls and a Food Frequency Questionnaire were completed during an interview with the participants to gather data on dietary patterns over a period of three consecutive days. Additionally, the contents of one lunch box per participant were recorded and weighed. Anthropometrics and socio-demographics were also completed during the interview. Results: The three 24-Hour Recall nutrient measurements revealed a low energy intake in 91 percent for the girls and 77 percent for the boys who were consuming below the recommended Estimated Energy Requirement for energy. The lunchboxes contributed one-third of the daily nutrient intake of the children. The 24-Hour recall revealed an energy-dense, carbohydrate-based diet. The contribution of total fat (30-32%) to the total energy is higher than the World Health Organization (WHO) recommendation of 15-30 percent. The daily fruit and vegetable intake (215.1g and 216.9g), according to the 24-Hour recall and lunchbox analysis respectively, was insufficient compared to the WHO-recommendation of >400g /day. Although the mean intake of most of the nutrients was sufficient, a large number of the participants did not meet requirements for the age group. The risk of overweight was high (24% for girls and 29.2% for boys) with 1.5 percent falling into the obese category. Conclusion: The results of the study indicated a high-fat and carbohydrate intake and a very low fruit and vegetable intake. The girl participants had better food choices for the lunchboxes but the majority of the participant’s daily intake did not meet the basic requirements of a balanced diet. The risk of overweight in the age category is an increasing problem among low- and high-income countries. Nutritional education should concentrate on healthy food choices in school lunchboxes as a large part of the day is spent at school.

The reintroduction of lions, cheetahs and African wild dogs to Kwandwe Private Game Reserve in the Eastern Cape Province of South Africa created the opportunity to study the biology and behaviour of these large carnivores in an enclosed system. The research focused on space utilisation and feeding ecology of the predators, using standard observational methods. Changes in the structure of the carnivore guild, and changes in the prey base that occurred during the study were used as natural experiments to examine factors affecting space use and diet. In general, the diets of the predators were similar to previous studies and prey abundance was more important than prey species size in determining prey selection. Changes in the abundance of certain prey species was matched by a dietary switch in lions from kudu to warthog and an increase in the proportion of springbok kills by the cheetahs. There was no significant difference in the proportions of prey species detected by ad hoc or continuous observations. Core areas occupied by the predators were significantly smaller than home ranges except when females were denning. Home ranges overlapped both within and between species, but there was very little overlap of core areas. An increase in the number of lion prides in the area during the study resulted in an increase in overlap of home ranges of lions and cheetahs, but did not result in a change in home range size. Space use by female cheetahs with cubs increased as the cubs grew older. The use of thicket vegetation by cheetahs decreased with an increase in the number of lion prides. Minimum Daily Energy Expenditure, energy intake and net benefit were calculated for the predators using data from continuous observations. All predators exhibited a large net benefit and the net benefit for single female cheetahs was greater than for the members of the coalition. Net benefit for the alpha pair of African wild dogs was lower than that of the pack.