Theses and Dissertations (Agriculture, Animal Health and Human Ecology)

A model to achieve continuous improvement and innovation in the freshwater production of the sharptooth catfish, clarias gariepinus, in South Africa

Mon, 22 Aug 2022 00:00:00 GMT

A model to achieve continuous improvement and innovation in the freshwater production of the sharptooth catfish, clarias gariepinus, in South Africa Moroasui, Yvonne Matebo Global population is ever - increasing and demand for animal nutrition is also on the rise. Fish is considered to be the healthiest food on the planet and less harmful to the environment. People rely on the oceans for their daily protein intake. Capture fisheries is near extinction and aquaculture is identified as a solution to address this gab. Aquaculture has played a critical role in global food security and has grown ever – since 1970 by 7.5% yearly. Aquaculture businesses in South Africa are producing less than 1% of global production. Aquaculture small businesses are not profitable and „business as usual approach‟ is not enough to develop viable businesses. New innovative ways of producing more food and improving nutrition are essential. Continuous Improvement and Innovation (C I& I) is a business management strategy that concentrates thinking and action on the things that makes the real difference and was identified as a solution to disrupt businesses with the aim of achieving improvement and innovation and acquire profit. The study was conducted in five provinces of South Africa using mixed-method research methodology underpinned by paradigms, methodology, core methods and CI & I tools. Focus groups, in - depth - interviews, field notes, questionnaire and experiment were used as data collection instruments. The CI & I model is made of eight steps which are focus, situation analysis, impact and influence, action design, action implementation, performance assessment, creation & synthesis and refocus. The results showed that 30 projects were interested in the study and the opportunity of being involved in the study was high with mean score of 9 articulating that CI & I was a teaching and guiding process and it gave hope. Cycle 1 revealed that 87% partners focused on owning viable and sustainable businesses that generated income and created employment. In situational analysis, 93% of partners needed to secure market; 70% articulated lack of water; 13% reported lack of electricity. Impact and Influence revealed that 68% projects reported securing market access and improving water access as opportunities with high impact and influence. A total of 64% reported improving feed supply as critical; 54% increase number of ponds; 50% obtain equipments; 43% improve skills; 39% reported preventing predation and increasing number of fish; 36% obtain funding; 32% improving security; 21% establish accredited processing facility and improve electrical works. According to the profit driver tree the strongest drivers in the study were marketing, genetics, nutrition and management. In action design: the action was to secure local market via a questionnaire, to secure off- takes at a required price, branding, design business cards and posters and advertise on radio, shops and billboards. The action to have water access was to drill boreholes and obtain water licenses. The action for improving feed supply was to determine the effect of locally available food such as live earthworms and tilapia fish on the growth of catfish and demonstrate the applicability of the model in real life researches. The action for improving technical skills was attending practical training. The action for improving security was to install security fencing and also purchase equipments for fish harvesting and processing. The action to obtain funding was to apply to government, banks and other private businesses (sponsors). Action implementation: Business stickers were designed and a date on local radio station was secured, social media page was created. The site where experiment was conducted was prepared and experimental materials were out-sourced and the experiment was conducted. Dates were secured for the training venue and the trainer. Quotations were obtained for the fencing and some partners were designing a trapping machine. Communication was not received on the progress of the construction of fish processing plant. In performance assessment: market access, signed orders for potential customers were secured. Signed orders for market liaison to fit product to market was also achieved. Small- scale partners had a secured market due to the newly completed processing plant. The results from earthworm experiment were analyzed. Creation & Synthesis revealed that 22% of the project were not registered and lacked funding; and they needed to obtain funding and develop a business plan. 27% of partners required funding to realize businesses growth. Refocus was to obtain funding and be involved in the development of a business plan. The study contributed to real life experiences of farmers in catfish farming who worked on a rigorous and spiraling CI & I model. Issues such as market, funding, nutrition, management and electricity were strongest drivers that required attention for small business to become profitable and sustainable. The outcomes would contribute significantly to aquaculture policy makers and managers in South Africa for improved development of the sector.

An econometric analysis of the cost of fruit and vegetable waste in retail operations in Durban City, KwaZulu-Natal Province

Thu, 09 Apr 2026 00:00:00 GMT

An econometric analysis of the cost of fruit and vegetable waste in retail operations in Durban City, KwaZulu-Natal Province Khuzwayo, Makhosazane Food waste has become a major global sustainability challenge with significant envi-ronmental, economic, and social implications. In South Africa, approximately 10.3 mil-lion tonnes of food are wasted annually, resulting in substantial economic losses across the food supply chain. Despite increasing concern regarding food waste, lim-ited empirical research has focused on the economic costs and operational determi-nants of fruit and vegetable waste within retail operations particularly in urban contexts such as Durban. This study aimed to quantify the cost and monetary value of fruit and vegetable waste in retail operations in Durban City, KwaZulu-Natal Province and to identify the factors influencing waste generation. The study further sought to propose pathways for reduc-ing fruit and vegetable waste within retail environments. A positivist research paradigm and quantitative cross-sectional research design were adopted. Data was collected from 100 selected retail stores located within the Durban Central Business District using structured questionnaires, waste composition analysis, and direct observation methods. Cluster sampling was used to group retail stores within four precincts of Durban CBD. Data were analysed using descriptive statistics, multiple linear regres-sion and ordinal logistic regression through SPSS and Microsoft Excel. The findings revealed that leafy vegetables constituted the highest category of fruit and vegetable waste while berries generated relatively lower waste volumes but higher monetary losses due to their high market value. The multiple regression model indi-cated that the predictor variables collectively explained a significant proportion of the variation in food waste costs (R2=0.971, p<0.001). However, at the individual level, only the total quantity of fruits and vegetables sold per month significantly influenced food waste costs, while landfill disposal costs were not statistically significant inde-pendent predictor. The ordinal logistic regression results showed that none of the op-erational predictor variables independently explained food waste generation, suggest-ing that food waste within retail environments is systemic and multifactorial. Retailers identified infrastructure limitations, handling practices, demand forecasting chal-lenges, and awareness as important contributors to food waste generation. The study viii contributes to the limited body of knowledge on retail fruit and vegetable waste quan-tification within South Africa and provides evidence-based recommendations aligned with the National Waste Management Strategy (NWMS). The study recommends in-tegrated interventions focusing on awareness, improved planning and forecasting, in-frastructure investment, redistribution initiatives and technology-based waste manage-ment systems to reduce fruit and vegetable waste within retail operations.; Imfucuza yokudla isibe yinselele enkulu yokuzinza emhlabeni wonke enemiphumela ebalulekile kwezemvelo, kwezomnotho, kanye nakwezenhlalo. ENingizimu Afrika, cishe amathani ayizigidi eziyi-10.3 okudla ayachithwa minyaka yonke, okuholela eku-lahlekelweni okukhulu kwezomnotho kulo lonke uchungechunge lokuhlinzekwa ko-kudla. Naphezu kokukhathazeka okwandayo mayelana nemfucuza yokudla, ucwan-ingo olulinganiselwe olusekelwe emibonweni luye lwagxila ezindleleni zomnotho kanye nasezicini zokusebenza kwemfucuza yezithelo nemifino emisebenzini yokuthengisa ikakhulukazi ezindaweni zasemadolobheni njengeTheku. Lolu cwaningo luhlose ukulinganisa izindleko kanye nenani lemali lemfucuza yezithelo nemifino emisebenzini yokuthengisa eDolobheni laseTheku, eSifundazweni saKwa-Zulu-Natali kanye nokuhlonza izici ezithonya ukukhiqizwa kwemfucuza. Ucwaningo luqhubeke nokuzama izindlela zokunciphisa imfucuza yezithelo nemifino ezindaweni zokuthengisa. Kwamukelwa indlela yokucwaninga ekhuthazayo kanye nomklamo wocwaningo oluhlanganisa izingxenye eziningana. Idatha yaqoqwa ezitolo zo-kuthengisa eziyi-100 ezikhethiwe eziseSifundeni Sebhizinisi Esiphakathi saseT-hekwini kusetshenziswa imibuzo ehlelekile, ukuhlaziywa kokwakheka kwemfucuza, kanye nezindlela zokubuka ngqo. Ukusampula kweqembu kwasetshenziswa ukuqoqa izitolo zokuthengisa ngaphakathi kwezindawo ezine ze-CBD yaseThekwini. Idatha yahlaziywa kusetshenziswa izibalo ezichazayo, ukuhlehla okuqondile okuningi kanye nokuhlehla kwe-ordinal logistic nge-SPSS kanye ne-Microsoft Excel. Okutholakele kwembule ukuthi imifino enamaqabunga yakha isigaba esiphezulu sem-fucuza yezithelo nemifino kuyilapho amajikijolo ekhiqiza inani eliphansi lemfucuza kodwa elahlekelwa kakhulu yimali ngenxa yenani lawo eliphezulu lemakethe. Imodeli yokubuyela emuva okuningi ibonise ukuthi iziguquguquli zokubikezela zichaze ingxenye enkulu yokwehluka kwezindleko zemfucuza yokudla (R2=0.971, p<0.001). Kodwa-ke, ezingeni lomuntu ngamunye, inani eliphelele lezithelo nemifino ethen-giswayo ngenyanga kuphela elithonye kakhulu izindleko zemfucuza yokudla, kuyilapho izindleko zokulahla imfucuza zazingeyona into ebikezela ngokuzimela ebaluleke kakhulu ngokwezibalo. Imiphumela yokubuyela emuva kwe-ordinal logistic ibonise ukuthi azikho iziguquguquli zokusebenza ezichaza ngokuzimela ukukhiqizwa x kwemfucuza yokudla, okuphakamisa ukuthi imfucuza yokudla ezindaweni zo-kuthengisa ihlelekile futhi inezici eziningi. Abathengisi bathole imikhawulo yengqal-asizinda, imikhuba yokuphatha, izinselele zokubikezela isidingo, kanye nokuqwashisa njengezinto ezibalulekile ezibangela ukukhiqizwa kwemfucuza yokudla. Ucwaningo lufaka isandla olwazini olulinganiselwe mayelana nokulinganiswa kwemfucuza yezithelo nemifino ezitolo eNingizimu Afrika futhi lunikeza izincomo ezisekelwe ebufa-kazini ezihambisana ne-National Waste Management Strategy (NWMS). Ucwaningo luncoma ukungenelela okuhlanganisiwe okugxile ekuqwashiseni, ekuhleleni naseku-bikezeleni okuthuthukisiwe, ekutshalweni kwezimali kwengqalasizinda, ekusat-shalalisweni kabusha kwezinhlelo kanye nezinhlelo zokuphathwa kwemfucuza esekelwe kubuchwepheshe ukuze kuncishiswe imfucuza yezithelo nemifino emisebenzini yokuthengisa.; Voedselvermorsing het 'n groot wêreldwye volhoubaarheidsuitdaging geword met beduidende omgewings-, ekonomiese en sosiale implikasies. In Suid-Afrika word on-geveer 10,3 miljoen ton voedsel jaarliks vermors, wat lei tot aansienlike ekonomiese verliese regdeur die voedselvoorsieningsketting. Ten spyte van toenemende kommer oor voedselvermorsing, het beperkte empiriese navorsing gefokus op die ekonomiese koste en operasionele determinante van vrugte- en groentevermorsing binne klein-handelbedrywighede, veral in stedelike kontekste soos Durban. Herdie studie het ten doel gehad om die koste en monetêre waarde van vrugte- en groentevermorsing in kleinhandelbedrywighede in Durban Stad, KwaZulu-Natal Provinsie, te kwantifiseer en die faktore wat afvalgenerering beïnvloed, teidentifiseer. Die studie het verder gepoog om paaie voor te stel vir die vermindering van vrugte- en groentevermorsing binne kleinhandelomgewings. 'n Positivistiese navorsingspara-digma en kwantitatiewe dwarssnitnavorsingsontwerp is aangeneem. Data is in-gesamel van 100 geselekteerde kleinhandelwinkels in die Durban Sentrale Sakege-bied deur gebruik te maak van gestruktureerde vraelyste, afvalsamestellingsanalise en direkte waarnemingsmetodes. Trossteekproefneming is gebruik om kleinhandel-winkels binne vier gebiede van Durban CBD te groepeer. Data is geanaliseer met behulp van beskrywende statistieke, veelvuldige lineêre regressie en ordinale logistiese regressie deur SPSS en Microsoft Excel. Die bevindinge het aan die lig gebring dat blaargroente die hoogste kategorie van vrugte- en groente-afval uitmaak, terwyl bessies relatief laer afvalvolumes, maar hoër monetêre verliese as gevolg van hul hoë markwaarde, gegenereer het. Die meervoudige regressiemodel het aangedui dat die voorspellerveranderlikes gesamentlik 'n beduidende deel van die variasie in voedselafvalkoste verklaar het (R2=0.971, p<0.001). Op individuele vlak het slegs die totale hoeveelheid vrugte en groente wat per maand verkoop is, egter voedselafvalkoste beduidend beïnvloed, ter-wyl stortingsterreinverwyderingskoste nie statisties beduidende onafhanklike voor-speller was nie. Die ordinale logistiese regressie-resultate het getoon dat geeneen van die operasionele voorspellerveranderlikes onafhanklik die opwekking van voed-selafval verklaar het nie, wat daarop dui dat voedselafval binne kleinhandelomgewings xii sistemies en multifaktoriaal is. Kleinhandelaars het infrastruktuurbeperkings, hanter-ingspraktyke, vraagvoorspellingsuitdagings en bewustheid as belangrike bydraers tot die opwekking van voedselafval geïdentifiseer. Die studie dra by tot die beperkte hoev-eelheid kennis oor die kwantifisering van kleinhandel-vrugte- en groente-afval in Suid-Afrika en verskaf bewysgebaseerde aanbevelings wat in lyn is met die Nasionale Afvalbestuurstrategie (NWMS). Die studie beveel geïntegreerde intervensies aan wat fokus op bewustheid, verbeterde beplanning en voorspelling, infrastruktuurbelegging, herverdelingsinisiatiewe en tegnologie-gebaseerde afvalbestuurstelsels om vrugte- en groentevermorsing binne kleinhandelbedrywighede te verminder.

Determination of the nutritional and phytochemical composition of monsonia burkeana (special tea) and its potential anti-proliferative effects on cancer cell lines

Sat, 01 Nov 2025 00:00:00 GMT

Determination of the nutritional and phytochemical composition of monsonia burkeana (special tea) and its potential anti-proliferative effects on cancer cell lines Ngwenya, Sandile Manzi Traditional medicinal plants have long been used to treat ailments in humans and animals. Africa is rich in such plants, many of which have been studied for bioactivities like anticancer, antimicrobial, and anti-inflammatory effects, though many remain uncharacterized. Monsonia burkeana (“special tea”) is widely consumed for its health benefits, usually as a decoction. Its antimicrobial properties are known; however, its phytotoxicity and antiproliferative activities remain underexplored. Elucidating these could benefit both traditional medicine and the pharmaceutical industry. This study aimed to investigate the effects of drying methods on the nutritional composition of special tea, identify bioactive compounds in its crude extract, and evaluate antiproliferative activities in cancer cell lines, offering insights for pharmaceutical development and commercial potential. The specific objectives included assessing nutritional composition, profiling bioactive compounds, and testing cytotoxicity against lung, colorectal, and liver cancer cell lines. Samples from Sekhukhune, Lanseria, Brits, and Rietondale were dried using shade, oven, and freeze-drying methods. Nutritional elements were analyzed by inductively coupled plasma mass spectrometry (ICP-MS), phytochemicals profiled using nuclear magnetic resonance (NMR), liquid chromatography-mass spectrometry (LC-MS), and gas chromatography-mass spectrometry (GC-MS), and anticancer properties evaluated through the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and caspase-3 activity assays. The results demonstrated a consistent elemental composition across all regions, with all 24 elements present in each sample and collection region. NMR analysis identified phenols, alkyls, esters, and ethers, while GC×GC/TOF-MS detected various bioactive compounds, including oxalic acid, β-caryophyllene, caryophyllene oxide, phytol, squalene, and vitamin E. LC-MS analysis confirmed the presence of additional key phytochemicals such as castalagin, vescalagin, acutissimin B, epicatechin, citroside, trifolin, 1,6-digalloyl-beta-D-glucopyranose, 5,7-dihydroxy-2-(4-hydroxy-3-methoxyphenyl)-3-{[3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy}-4H-chromen-4-one, and puerarin 4',6''-diacetate. The MTT assay revealed significant cytotoxic activity against lung and liver cancer lines, however, activity against the colorectal cancer cell line was lower compared to that demonstrated against the other two cancerous cell lines. In conclusion, the combination of essential micro- and macronutrients, bioactive phytochemicals, and demonstrated cytotoxic effects against cancer cell lines highlights the medicinal value of M. burkeana plants. The study provides strong evidence that Monsonia burkeana is a promising alternative for cancer treatment. These findings not only validate its traditional use and benefits over the years but also highlight its potential for pharmaceutical applications.

Investigation of egg quality characteristics of Ross 308 broiler breeder chickens

Tue, 28 Apr 2026 00:00:00 GMT

Investigation of egg quality characteristics of Ross 308 broiler breeder chickens Nkune, Achy Poultry products such as chicken eggs and meat continue to have an important economic impact and are important to the growth of a country`s economy. Moreover, poultry products are globally consumed in greater quantities than any other source of animal protein, because they are reasonably priced. Ross 308 broiler chicken is the best breed of chicken nationally which was bred specifically for meat. Poultry breeders focus on egg characteristics in their selection process for reproduction, because poor egg quality results in economic losses during production. This study was conducted to investigate the characteristics of egg quality traits, the correlations among these factors, how the egg weight influences egg quality traits, and to estimate the weight of the egg from egg quality traits in Ross 308 broiler breeder chickens. A total of 1000 eggs were purchased from Daybreak Farm in Bela Bela Local Municipality, Limpopo province of South Africa to conduct the study. Eight external traits of egg quality, including egg length, egg width, shell weight, shell index, shell surface area, unit surface shell weight and shell ratio, and five internal egg quality traits such as yolk weight, albumen weight, albumen ratio, yolk ratio and yolk/albumen. The descriptive statistics were used to quantify the egg quality traits, and the correlation between weight and quality traits of egg was investigated using Pearson`s correlation, One-way Analysis of Variance (ANOVA) was applied to investigate which egg quality traits are affected by egg weight and stepwise regression analysis was used to come up with best fit model to predict egg weight from egg quality traits. The descriptive statistics revealed that egg weight had a minimum and maximum value of 32.59 g and 98.25, g respectively. Egg length had a minimum value of 46.61 mm and a maximum value of 70.36 mm, and yolk weight had a minimum value of 5.31 g and a maximum value of 34.02 g. One-way ANOVA revealed that egg weight has a substantial effect (p < 0.05) on egg length, egg width, shell weight, shell index, shell surface area, unit surface shell weight, shell ratio, yolk weight, albumen weight, albumen ratio, yolk ratio and yolk/albumen. Pearson’s correlation findings displayed that egg weight had a highly positive, remarkable association (p < 0.01) with egg length, egg width, shell weight, unit surface shell weight, albumen weight, yolk weight, yolk ratio and yolk/albumen. In addition, negative correlation (p > 0.05) was identified between egg weight and shell index, shell ratio and albumen ratio. Stepwise regression findings revealed that the model, including yolk weight, yolk ratio, albumen ratio and albumen weight, was the best-fitted model (R2 = 1.00 and RMSE = 0.05) for estimation of egg weight. The model including yolk weight, albumen weight and yolk ratio was the second best (R2 = 1.00 and RMSE = 0.34). The study concludes that the improvement of yolk weight, yolk ratio, albumen weight and albumen ratio might improve the egg weight of the Ross308 broiler chicken breed. The results of this study may be useful to farmers in considering egg quality traits during breeding to improve the egg weight of Ross 308 broiler breeder chickens.