Fouling of heat treatment equipment in the dairy processing industry is an expensive and persistent problem. The objective of this work was to develop a better understanding of the mechanisms of dairy fouling in heat exchangers and identify methods to control this build-up. This was part of a larger project investigating the interaction between spore-forming thermophilic bacilli (thermophiles) contamination and fouling deposits on internal surfaces of equipment. Two systems were developed to monitor the onset and build-up of fouling on the internal surfaces of two research heat exchangers. The first used a commercial sensor to measure the local heat flux and the temperature on the hot side of a plate type heat exchanger. The heat transfer coefficient was calculated and normalised with its value at the start of the run to reflect the contribution of fouling deposits to the thermal resistance, thus giving a real-time estimate of the rate of fouling. The second system used an energy balance over a tubular type heat exchanger and measured inlet and outlet temperatures to estimate the overall heat transfer coefficient thus giving a global measurement of fouling over the tubular heat exchanger. In both systems the plot of normalised heat transfer coefficient over time often stayed constant over an induction period, which was followed by a falling period indicative of growth in the fouling layer thickness and/or mass. Each system was validated by comparing the final value of the normalised heat transfer coefficient with direct measurements of fouling made at the end of a run namely: fouling deposit height for the local measurement and fouling deposit mass for the global measurement. The normalised heat transfer coefficient reported by each system correlated well with the corresponding direct measurement of the fouling layer. An important factor identified in this study was the effect of air bubble nucleation on fouling deposits. It was shown that bubbles that formed on the heated surface greatly reduced the length of the induction period to a matter of seconds rather than hours, as found in previous studies of fouling in the absence of surface bubbles. The rate of fouling was also enhanced while the bubbles remained at the surface. The structure of bubble type fouling layers was linked to the behaviour of the bubbles at the heated surface. Visual observations of these bubbles showed evidence of growth, vibration and coalescence during their period of attachment to the heated surface. Deposits from bubble type fouling consisted of all solid components found in the original milk solution, except lactose, in approximately the same ratio. By contrast fouling deposits reported in the literature with systems operating under the traditional protein denaturation mechanism were reported to consist mainly of whey proteins. Bubble induced fouling can be limited in a number of ways, the most effective being to maintain a high operating pressure in the equipment to ensure nucleation does not occur. Experiments conducted in this study showed that a pressure of 130 kPa.g was sufficient to suppress all bubble nucleation at the heated surface at a temperature of 90°C. Another method identified was the use of high linear fluid velocities to entrain any surface bubbles into the processing stream immediately upon nucleation. Linear velocities above 1.0 m/s were shown to achieve this goal in the miniature plate heat exchanger tested. However, this method is only partially successful because the local linear velocity varies with position in heat exchange equipment of complex geometries and can drop below the mainstream average velocity causing surface bubbles to form, especially in recirculation regions behind flow obstacles. A more reliable method, in situations where high operating pressures could not be used, involved conditioning the heated surface with a thin protein layer during the first few minutes of a run. Conditioning the surface resulted in bubble suppression even at high temperatures and low pressures, thus greatly extending the length of the induction period. Trials performed in this study showed that the addition of a proteolytic enzyme produced by psychrotrophic microbes greatly increased fouling. The enzyme destabilised the caseins which could attach directly to the heat exchange surface independently from the bubble fouling mechanism. Thus the quality of the milk is another important factor to consider. However, the addition of enzymes produced by thermophilic bacilli isolated from milk powder plants did not increase fouling. A theory describing the air bubble induced fouling mechanism is presented along with recommendations on how to reduce this fouling contamination in processing equipment.

Thesis (MSc (Paraclinical Sciences))--University of Pretoria, 2007. / Includes bibliographical references. Also available in print format.

The purpose of this study is to examine nine essential planning principles in the selecting and implementing an aid project. These nine principles will then be used to analyze BYU's involvement with the ADS dairy project. The project is presented from a historical viewpoint. An analysis is mainly given retrospectively at the end of the history of the BYU involvement phase of the project.

No description available.

Poverty is caused by inadequate income. Effective assistance to small-scale enterprises may benefit the urban and rural poor. Small enterprises have the potential to create employment, reduce poverty and support sustainable livelihoods, as small enterprises satisfy local needs, provide employment opportunities in local areas, increase income, ensure food security and improve health. The Department of Land Affairs has recently introduced policies such the Land Reform Policy to correct the injustices of South Africa’s past. During 2005, the KwaZulu-Natal Department of Agriculture and Environmental Affairs introduced the Agrarian Revolution Programme, in an effort to close the gap between the first and second economy. The Agrarian Revolution and the LRAD programmes encourage agribusinesses through the formation of co-operatives or trusts. The purpose of this study was to investigate the potential of an envisaged processing enterprise with a group of women from an LRAD project, within the Engadini Community Trust. An action research methodology was followed. A training manual was developed and training conducted with the Engadini women’s group through which they prepared a business plan, developed prototype products; conducted market research; estimated prices for the products and developed a marketing plan. The study results indicate that the group would have the technical skills to make a good quality product. The group is likely to face problems ensuring a sustainable supply of raw materials as the current supply of milk would hardly be sufficient to supply the target market sampled during the consumer survey. The success of the dairy processing enterprises depends heavily on the ability of the Engadini Trust to overcome internal social problems. Conflict between the Engadini dairy processing enterprise members and conflict within the larger Engadini Community Trust had a crippling effect on the dairy processing enterprise. The main recommendations for the group are that the group needs to secure a sustainable supply or fresh milk. A dairy processing facility that will meet food safety standards needs to be erected for the enterprise. The location of the dairy processing enterprise needs to be re-considered. To overcome internal conflict within the group, the women’s group needs to gain representation on the Engadini Community Trust’s Executive Committee, to ensure that the dairy processing enterprise interests are considered by the Trust. The main recommendations for small-scale enterprises are that they should ensure to have sustainable supply of good-quality raw materials and a reliable, sustainable market, even if the market is relatively small. Policy recommendations are that Government Departments such as the KwaZulu-Natal Departments of Agriculture and Environmental Affairs and Economic Development should consider adapting policies that will focus on funding individual enterprises, rather than group enterprises. A directorate or sub-directorate dedicated to the development of small and medium sized food processing enterprises should be created. The marketing section of the KwaZulu- Natal Department of Agriculture and Environmental Affairs should provide marketing information for small-scale food processing enterprises available to extension officers and small-scale enterprises.

The increasing price of oil and the destabilisation of the world’s climate are urging governments, businesses and individuals to constantly investigate energy-efficient technologies and methodologies and pursue the adoption of energy efficiency programmes in a global effort to reduce energy consumption, greenhouse gas emissions and ultimately energy costs. In New Zealand, one of the biggest industrial energy efficiency projects was started in 2002 by a multinational dairy company, the Fonterra Co-operative Group, in partnership with the energy service company Demand Response Ltd; the project currently aims at reducing by 15% the energy costs at all Fonterra’s major production sites throughout the country. This thesis, undertaken as part of the above project, examines the development and implementation of a structured and integrated energy monitoring and targeting methodology (M&T) for the most efficient operation of all Fonterra’s chilled water systems, with an initial focus on the ones installed at Clandeboye, one of the Fonterra’s sites involved in the energy saving project. A data collection system (Insite) was already in place at Clandeboye to enable storage and analysis of some of the site’s utility metering data. After identification of key chilled water system components and definition of data requirements for M&T purposes, an analysis of past energy consumption trends (based on multiple regression calculations) was carried out to develop an historical benchmark of the energy used, compare it with current energy performance and thus identify opportunities for future improvements. The creation of an M&T reporting system for presenting findings to operators and management was the last essential part of the thesis development. The study has highlighted that the robustness of the proposed regression model was badly affected by the unreliability of the existing data collection system and the uncertainty associated with poorly documented changes to operating conditions/plant configuration that had occurred over time. The conclusion is that, while the developed M&T methodology is theoretically valid and readily applicable, further developments are necessary (and recommended) to make it suitable for other similar systems.

Information on milk production could be useful in designing strategies that would help to improve milk production in communal farming systems. This study was conducted to determine milk production and calf performance of Nguni and crossbreds under smallholder cattle production conditions. Four trials were conducted in the study. The objective of the first trial was to determine farmer perceptions on milk production and calf rearing in smallholder areas. Data were obtained from 218 smallholder farmers, using a structured questionnaire. Smallholder farmer sector is constituted by small scale commercial farmers and communal farmers. Small-scale commercial farmers in South Africa obtained farms from the government through land claims or they bought the farms. Their farming background is a communal type. Communal farmers are farmers that are sharing the same grazing land and animals are managed according to the experience of the owner. The findings in this study indicated that there were numerous constraints to milk production in smallholder areas. These included lack of technical expertise and poor veterinary support services. The farmers also indicated that calf performance was low. The second trial was conducted to determine if there were differences in calf performance, gastrointestinal parasites and nutritionally-related blood metabolites between Nguni and crossbred calves. Body weights and faecal samples were collected monthly until weaning at six months. The levels of total protein, albumin, globulins, non-esterified fatty acids (NEFA), glucose, cholesterol and minerals were determined monthly. Nguni calves had higher birth weights than crossbreds (P<0.05). Average daily gain and weaning weights of Nguni calves were greater than crossbred calves (P<0.05. Nguni calves had lower total protein at early age after birth (P<0.05). However, at weaning Nguni calves had higher total protein than crossbreds (P<0.05). Nguni calves had higher levels of glucose and NEFA concentrations than crossbred calves (P<0.05). In the third trial, milk utilisation patterns in smallholder areas of the Eastern Cape were assessed. Cattle owners (n = 130) were randomly selected in three different regions to determine milk consumption patterns, milk sales, prices and factors influencing these activities. The information was gathered using milk recording sheets, which were administered in February (early lactation) and June (late lactation) in 2009. Milk consumption per household was similar among the three districts (P>0.05). Milk was utilised as both fresh and sour. Fresh milk was utilised with tea/coffee and porridge. Excess fresh milk was utilised to feed pets (mostly cats and puppies). The puppies were fed on mostly whey, and, at times, on fresh milk. Sour milk was utilised to prepare of umvubo (a mixture of sour milk and scrambled porridge (umphokoqo) or a mixture of sour milk and bread). In some cases, excess milk was given to neighbours as a form of social investment and fame. The quality of milk from Nguni and crossbred cows was compared in the fourth trial. Milk samples were evaluated for quality in early (February), mid (April) and late (June) lactation in 2009. The essential amino acids, non-essential amino acids and fatty acids were determined. Nguni milk had higher amino acids and fatty acids concentration than crossbreds (P<0.05). Nguni milk had higher arginine levels in the early and mid lactation periods compared to crossbred cows (P<0.05). Nguni milk had higher methionine and threonine levels than crossbred cows (P<0.05). Methionine levels in Nguni were 0.15, 0.19 and 0.18 in early, mid and late lactation while crossbred had 0.05, 0.05 and 0.06 (g/100ml), respectively. There were significant interactions between lactation stage and genotype for lysine levels with Nguni milk having higher (P<0.05) lysine levels in the mid and late lactation periods. Nguni cows had higher tyrosine, glycine and proline levels than crossbred cows (P<0.05). In the early lactation, Nguni cows had higher serine levels than crossbred cows (P<0.05). In mid lactation crossbred cows had higher serine levels than Nguni cows (P<0.05). There were significant differences between genotypes on fatty acid composition. Nguni milk had higher C12:0 levels than crossbreds (P<0.05). However, milk from crossbred cows had higher C14:0 levels than that for Nguni cows (P<0.05) and also had higher levels of C16:0 and C18:0 fatty acids compared to Nguni cows. Crossbred milk had higher levels of C18n1n9t in early lactation period than Nguni and decreased as the stage of lactation progressed (P<0.05). In the early lactation, the levels of C18n1nC in Nguni milk were higher (P<0.05) than in late lactation. In the mid and late lactation, crossbred cows milk had higher C18n1nC levels than in early lactation (P<0.05). Lactation stage and genotype affected saturated fatty, monounsaturated fatty acids, cis-fatty acids and omega 3 (n-3) to omega 6 (n-6). In general, Nguni milk had higher mineral composition than crossbred milk (P<0.05). In conclusion, Nguni calves performed better than crossbred calves under communal rangelands. There is a need for crossing Nguni cows with dairy breeds in commercial dairying by smalhoder farmers as a strategy for improving both milk quality and quantity.

PhDRDV / Institute for Rural Development / As has been the case in Eastern and Southern Africa, Zimbabwe continues to regard smallholder dairy farming as a viable strategy for reducing poverty and malnutrition, especially in rural areas. Although the country has since the early 1980s been promoting smallholder dairy development, available literature does not provide a clear picture of the extent to which the specific livelihoods of rural communities in terms of human, social, physical and financial capitals, have improved. Nor is there knowledge on its negative contribution to the farmers’ livelihoods. Thus, this study was undertaken to critically analyse the contribution of smallholder dairy farming towards the livelihoods of rural households using the Nharira dairy scheme as a focal area. The DfiD sustainable livelihood framework was used to build this understanding. Apart from characterizing the farmers, the contribution of smallholder dairy farming towards social, physical, human, natural and financial capitals was investigated. A sequentially integrated mixed methods approach was used. This was divided into two phases, which were quantitative and qualitative in nature. Results from the first phase were used to inform and design the second study. A census of the 21 active smallholder dairy farmers in Nharira, and management committee of the Nharira dairy processing plant was conducted. A household-focused questionnaire, key informant interviews, participatory mapping, record review, Global Positioning System (GPS) locating and focus group discussions were used to collect data. A tape recorder, GPS locator and camera were used as assistive devices during data collection. Thematic content analysis was used to analyse qualitative data and interpret participatory maps. Livelihood capital indices were derived per household and used to complement descriptive statistics as part of quantitative data analysis. A social capital index was computed for each household using collective action, empowerment, groups and networks, and trust and solidarity as its components. Resource stocks and access were the building blocks of the natural capital index. Income, savings and investments, and access to funding were used to derive the household financial capital index. Contribution of dairy farming to productive equipment (such as cattle herd size) and basic infrastructure (such as quality of housing) were used to calculate the physical capital index. The index for human capital was obtained taking into account education, workforce and employment, enabling environment, and health and wellness. Equal weights were applied to the components when deriving the household livelihood indices because each one of them was considered to be substantially important for sustainable livelihoods. The quantitative data were stored and analysed using the International Business Machines (IBM) Statistical iii Package for Social Sciences (SPSS) version 24. Pearson correlation coefficients, means and standard deviations were calculated. Most of the farmers (65 %) were female. Approximately, 95 % of the women farmers were literate. Only 1 % of the farmers were youth (< 35 years old), a situation that threatened the sustainability of smallholder dairy farming. A daily smallholder dairy farming routine was derived using the focus group and participatory mapping results. This showcased the various daily activities and linked them with the household members actively involved. Smallholder dairy farming was found to be labour intensive. This might deter the farmers from diversifying into other livelihood strategies. Smallholder dairy farming was observed to have strengthened financial, human, natural, physical and social capitals in the local households. However, the respective indices of 0.59 and 0.52 for social and natural capitals, suggested that smallholder dairy farming impacted on these more than any other. Even though social capital was strong, further reinforcement through improved smallholder dairy farming activities was still vital because of its power of enhancing access to other forms of livelihood capitals. Human and physical capitals had the least index scores of 0.48 and 0.47, respectively. On average, the overall household livelihood capital index as a result of smallholder dairy farming was 0.51. One of the study respondents supported the positive contribution in the following way, ‘’Zvakanakira dairy hatingazipedzi. Tinotoda zuva rese” (There are many positive things that we attribute to our involvement in smallholder dairy farming. Narrating these demands considerable time). It was concluded that smallholder dairy farming significantly strengthened livelihood capitals of households involved in it. The results of the current study suggest that smallholder dairy farming is a viable option for improving household livelihood capitals. Thus, establishment of dairy farming schemes in rural areas should be promoted. However, the participation of youth in smallholder dairy farming as enterprise owners deserves attention because it threatens sustainability of the sector. An integrated multiple angle view encompassing technical, social, institutional, economic and organizational ideas of the impact of dairy farming as a livelihood strategy on household capital portfolio was provided. Moreover, application of the sustainable development framework to understanding the smallholder dairy farming context at household level was a novel way of understanding the local realities. Lastly, a set of variables that can be utilised to measure livelihood capitals of households involved in smallholder dairy farming-related activities was distilled.

M. Tech. (Biotechnology, Department of Biosciences, Faculty of Applied and Computer Sciences), Vaal University of Technology. / The Organization for Economic Co-operation and Development (OECD) and the Food and Agriculture Organization (FAO) of the United Nations predict that milk production and the dairy sector will remain one of the fastest-growing agricultural subsectors over the coming decade. The global milk production is projected to expand over the 2011-2020 period at an annual rate of 2%. In South Africa alone, approximately 14 – 15 million litres of milk are wasted annually due to microbial spoilage. Therefore, the identification of the spoilage microorganisms in the milk products is necessary. This will contribute towards the design of appropriate measures to prevent wastage due to spoilage and in turn contribute towards sustainability of the sector. Accordingly, one hundred samples of spoiled full cream UHT milk were collected from two plants of each of the two largest milk processors. These samples were examined visually, and the pH was measured. A presumptive identification up to genus level was conducted by examining morphological features and conducting Gram-stain, catalase and oxidase tests. Species-specific identification was done by using the Analytical Profile Index and Biolog system. Molecular profiling was done by sequencing the rDNA genes. The main spoilage organisms identified in the samples were Pseudomonas, Micrococcus, Bacillus, Enterococcus and Lactobacillus. All organisms belonging to the five genera were psychrotrophs, which are commonly found in biofilms in UHT milk processing equipment. Therefore, according to the study, the spoilage bacteria apparently entered into the milk due to inadequate cleaning-in-place (CIP) processes. More importantly, further studies should be conducted in order to identify the spoilage microbes and how CIP processes can be improved.

Thesis (M. Tech.) -- Central University of Technology, Free State, 2008 / In this study, the development and implementation of a quality-monitoring program for raw milk as part of the quality management system of a milk processor was studied. Various aspects that contribute to raw milk quality were also included. Ten factors that are important in the production of good quality raw milk were summarised in the Ten Point Plan for the production of quality raw milk. Thirty-eight producers, who have supplied raw milk to the processor over a period of five year, were involved in this program. The producers are located all over the Northwest Province. Sixty thousand litres of milk is processed at the processor daily. The milk is taken in from the farms on alternative days by tankers supplied by the processor. A mark sheet was developed to evaluate control points during milking that can be measured directly from the laboratory. This was done monthly. Factors that could not be measured in the laboratory were evaluated when visits to the milk parlours were done twice a year. At the end of the year, the results of the mark sheet as well as the results of the parlour audits were compiled on a quality chart and the results were calculated as a percentage. The processor used the results of the quality charts to reward producers for quality milk. It was found that producers do not have the necessary infrastructure and knowledge to analyse milk. Analysing the raw milk and releasing the results to the producer are important measures to identify and manage problem areas that can pose a risk to the production of good quality raw milk. It is very important to supply the producer with the correct and relevant information because most of the representatives of companies, which visit the farms, supply information to the benefit of the product they sell. A formal monitoring program ensures that raw milk adhere to quality measures due to the fact that producers know the basic principles necessary for the production of good quality raw milk and the fact that the producer can implement measures in his/her own unique farm environment. The implementation of the Ten Point Plan for the production of quality raw milk at the processor had a significant influence on the quality of raw milk that was bought from producers. During times of milk shortages, the processor had to buy milk from alternative sources, which have no quality-monitoring program. Most of the times, this milk did not comply with the law regarding the total bacterial count, the coliform count, and the E. coli count. Record keeping is an important part of the management system of a dairy. Results from this study stressed a meaningful relationship between the keeping of records as mentioned in the Ten Point Plan and the production of good quality raw milk. It is recommended that producers be sharpened regarding the requirements for the production of good quality raw milk. Purchasing good quality raw milk assured the marketing of the best quality dairy products to the consumer. The contribution of this study to the dairy industry is the fact that the implementation of a quality-monitoring program ensures the maintenance of a sustainable quality of raw milk to the industry.