Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: The aim of this study was to determine the rate of transfer of melamine as fertilizer ingredient to kikuyu pastures and if melamine would be transferred from the fertilized pasture to cow’s milk. Three trials were conducted in the study, viz. a pilot pot plant trial, an applied pasture trial and a milk production trial. Melamine is a commercially available industrial chemical with a high nitrogen content. Large quantities of melamine waste can sometimes be incorporated into crop and pasture fertilizers due to the high N content. An initial pot plant trial with kikuyu was conducted to determine whether melamine would be absorbed as such from the soil to the plant material. The pots were fertilized in the form of melamine adulterated Chinese maize Gluten 60, at a rate equivalent to 8.8 kg of melamine/ha. Results indicated that melamine was indeed absorbed and 7 days after fertilization, the concentration of melamine in the grass was 228 mg/kg. An applied pasture trial was then conducted were three pastures of 0.3 ha each were used. One pasture served as a control and received N fertilization in the form of LAN at a rate of 40 kg N/ha. The other two pastures also received LAN, but with 10% (Treatment 1) and 20% (Treatment 2) of the LAN-N substituted with melamine-N. All three pastures also received P-fertilization in the form of Single Superphosphate at a rate of 20 kg P/ha and KCl fertilizer at a rate of 50 kg K/ha. Pasture samples were taken once a week for 10 weeks, each time at the exact same spot in each camp. Samples were dried and finely milled before analysis via LC-MS/MS for melamine content. The initial concentration of melamine in the grass of Treatment 2 was higher than that in the grass of Treatment 1. The rate at which melamine decayed in the plant material was found to be quite similar for the two melamine treatments. In this trial, melamine took around 10 weeks to reach undetectable levels in the grass. It was concluded that melamine was absorbed as such from the soil by pasture grass when included in a fertilizer. For the milk production study, eighteen lactating Holstein cows, 60 ± 5.1 (SE) DIM, with a daily milk production of 36.5 ± 2.0 (SE) kg/d and weighing 609 ± 12.8 (SE) kg, were stratified according to milk production and then randomly allocated to three groups of six cows. The groups were then randomly allocated to the three pastures used in the applied pasture trial. Cows were kept on the melamine fertilized pasture for 9 days, in which they were allowed to graze the pasture for approximately 10 hours each day. After the 9 day period, melamine was withdrawn by placing the cows on the control pasture that did not receive melamine contaminated fertilization for another 7 days. During these 16 days, milk was collected twice a day, viz. during the morning and afternoon milkings. Milk samples of each cow were sub-divided into two samples, one was preserved with potassium dichromate and analysed for milk composition and the other was frozen until analysed for melamine by LC-MS/MS. For the duration of the trial, melamine containing milk was destroyed in order to prevent it from contaminating milk collected from the rest of the herd. Results from the analysis for melamine confirmed that melamine was transferred from melamine fertilized pasture to milk. In this study, it took 6 days from melamine withdrawal for melamine to reach undetectable levels in the milk. It was also found that the melamine fertilized pasture did not have any significant effect on the average milk production and milk composition of the cows. The aim of the study was met and it was confirmed that melamine can be transferred from fertilizer to the soil, to the pasture and to the milk of cows grazing these pastures. / AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om die tempo van oordrag van melamien as bemestingstof na Kikuyu weiding te bepaal, asook om te bepaal of melamien oorgedra sal word vanaf die bemeste weiding na melk. Drie proewe is uitgevoer wat ‘n potplant loodsproef, ‘n toegepaste weidings proef en ‘n melkproduksie proef ingesluit het. Melamien is ʼn kommersieël-beskikbare industriële chemikalieë met ʼn hoë stikstof inhoud. Groot hoeveelhede van melamien-afval kan soms in kunsmis ingesluit word vir die bemesting van gewasse en weidings, weens die hoë stikstof inhoud van melamien. ʼn Potplant loodsproef met Kikuyu is uitgevoer om te bepaal of melamien vanaf die grond deur die plantmateriaal geabsorbeer word. Melamienbemesting is in die vorm van vervalste Chinese mieliegluten 60 toegedien teen ʼn hoeveelheid gelykstaande aan 8.8 kg melamien/ha. Die resultate van hierdie proef het getoon dat melamien wel deur die plantmateriaal geabsorbeer is en 7 dae nadat bemesting toegedien is, was die konsentrasie van melamien in die gras 228 of mg/kg. ʼn Toegepaste weidingstudie is uitgevoer waar drie kampe van 0.3 ha elk gebruik is. Een van die kampe het as ʼn kontrole gedien en het stikstof bemesting in die vorm van KAN teen 40 kg N/ha ontvang. Die ander twee kampe het KAN bemesting ontvang waar 10% (Behandeling 1) en 20% (Behandeling 2) van die KAN-N deur melamien-N vervang is. Al drie kampe het ook fosfaatbemesting in die vorm van Enkel Superfosfaat ontvang teen 20 kg P/ha, asook KCl kunsmis teen 50 kg K/ha. Weidingmonsters is eenmaal per week op dieselfde plek in elke kamp geneem vir 10 weke nadat bemesting toegedien is geneem. Monsters is gedroog en daarna fyngemaal voordat dit vir melamieninhoud geanaliseer is met behulp van LC-MS/MS. Die aanvanklike melamienkonsentrasie in die gras van Behandeling 2 was hoër as die in die gras van Behandeling 1. Die tempo waarteen die melamienkonsentrasie in die plant materiaal afgeneem het, was baie dieselfde vir Behandelings 1 en Behandeling 2. Dit het ongeveer 10 weke geneem voordat die melamien in die gras nie-waarneembare vlakke bereik het. Die gevolgtrekking is gemaak dat melamien wat in die vorm van kunsmis toegedien word, as sodanig uit die grond geabsorbeer word deur die gras. Vir die melkproduksiestudie is agtien lakterede Holsteinkoeie, 60 ± 5.1 (SE) dae in melk, met ‘n daaglikse melkproduksie van 36.5 ± 2.0 (SE) kg/dag en ‘n liggaamsmassa van 609 ± 12.8 (SE) kg, volgens hul melkproduksie gerangskik en ewekansig in drie groepe van ses koeie elk ingedeel. Die groepe is daarna ewekansig aan die drie kampe, wat in die toegepaste weidingstudie gebruik is toegedien. Die koeie is vir 9 dae op die melamienbemeste weidings gehou, waartydens hulle toegelaat is om vir ongeveer 10 ure elke dag te wei. Na die tydperk van 9 d, is die koeie vanaf die melamienbemeste weidings onttrek deur hulle op die kontroleweiding te plaas vir ʼn verdere 7 dae. Gedurende hierdie 16 dae is melkmonsters tweekeer per dag geneem, tydens die oggend- en die middagmelkings. Die melkmonsters van elke koei is vervolgens onderverdeel in twee monsters, waarvan een met kaliumdichromaat gepreserveer is vir die beplaing van melksamestelling, terwyl die ander een gevries is totdat dit later vir melamien inhoud ontleed is met behulp van LC-MS/MS. Melk van die koeie wat op die melamienweidings gewei het, is weggegooi om te voorkom dat melk van die res van die kudde gekontamineer kon word. Die resultate van die melamienanalises het getoon dat melamien oorgedra word vanaf die melamienbemeste weiding na die melk. Tydens hierdie studie het dit 6 dae geneem vandat koeie vanaf die melamienbemeste weidings onttrek is, totdat die melkmelamien nie-bepaalbare vlakke bereik het. Daar is bevind dat melamienbemeste weidings geen betekenisvolle uitwerking op die gemiddelde produksie en samestelling van die melk gehad het nie. Die doel van hierdie studie is bereik en daar is getoon dat melamien vanaf kunsmis na die grond, na die gras en na die melk oorgedra kan word wanneer koeie op weidings geplaas word wat melamienbemeste kunsmis ontvang het.

Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-10-17T21:55:57Z No. of bitstreams: 1 EvaristoLima.pdf: 4186670 bytes, checksum: 83283f7432d91813bbfcc344da875ca7 (MD5) / Made available in DSpace on 2017-10-17T21:55:57Z (GMT). No. of bitstreams: 1 EvaristoLima.pdf: 4186670 bytes, checksum: 83283f7432d91813bbfcc344da875ca7 (MD5) Previous issue date: 2017-09-04 / Fundação de Amparo à Pesquisa e ao Desenvolvimento Científico e Tecnológico do Maranhão / This theory has as objective to study the milk-producing region’s transformations in the micro-region of Imperatriz-MA, generated by the implementation of the Normative Instructions 51 and 62, of the Ministry of the Agriculture and Provisioning - MAPA, trying to verify how cattle farmers, family farmers, informal cheese dairies and dairy products are positioned at that market, working their own criteria on what they consider as the quality of the milk and the cheese that is produced. Edited respectively in the years of 2002 and 2011, these normative instructions constituted in the main devices of sanitary regulation for the section, establishing technical criteria for the production, identity, quality, collects and transport of the milk. In Imperatriz's micro-region, the largest milk-producing region of Maranhão, the effects of those Normative Instructions were felt indeed starting from the year of 2012, when the State’s Public Ministry-MPE began a interinstitutional campaign to combat to the "clandestine" milk and cheese, produced in establishments without formal registration in the organs of sanitary inspection. As a consequence of this campaign a rearrangement of the market of regional milk was observed, with the modification of the commercial relationships between the primary producers of milk and the formal (industries of dairy products) and informal (cheesemakers) units of improvement, when the dairy products assumed a position of defenders' to the implantation of the Normative Instructions, while the other actors seek to loosen up the application of those. Located in the field of the Economical Sociology, this study tried to approach the problem in subject being guided by the ideas that the processes of establishment of quality criteria constitute a preliminary moment to the establishment of the mercantile exchange and, that the quality of a product is not defined starting from an universal reference, but starting from values socially shared ruled in different notions of "justice" and “common good." Starting from the model of cités, elaborated by Boltanski and Thevénot (1991) it was possible to identify in the area studied two production models and improvement of milk in dispute, corresponding conceptually to the models of the conventions of the domestic world and of the industrial world, represented, respectively, by producers identified as artisanal cheesemakers and by the industry of dairy products. In this sense, these two worlds were described and analysed being looked for to apprehend the principles and evaluation criteria, mobilized by the actors involved in situations characterized by disputes around the quality patterns. In a more specific way, the milk, the actante (CALLON 2006) more present in the studied chain, was followed in its path to be transformed in cheese, when taken by the hands of the industry of dairy products, or by the hands of the artisanal cheesemakers, revealing in these courses the attributes of the human and non-human actantes involved in the improvement processes, the justifications and the ideological debates that emerge in these contexts, the differences in the verification forms and control inherent to each one of them, and the elements the factors that will compose the cognitive pictures in each world. These procedures allowed, finally, to summarize the main impacts and consequences of the dispute process for the quality and the establishment of a new configuration to the market of milk in Imperatriz’s MRH. / Esta tese tem como objetivo estudar as transformações da bacia leiteira na Microrregião de Imperatriz-MA, provocadas pela implementação das Instruções Normativas 51 e 62, do Ministério da Agricultura e Abastecimento - MAPA, procurando verificar como pecuaristas, agricultores familiares, queijarias informais e laticínios se posicionam nesse mercado, acionando critérios próprios sobre o que consideram como a qualidade do leite e do queijo produzido. Editadas respectivamente nos anos de 2002 e 2011, estas normativas se constituíram nos principais dispositivos de regulamentação sanitária para o setor, estabelecendo critérios técnicos para a produção, identidade, qualidade, coleta e transporte do leite. Na Microrregião de Imperatriz, a maior bacia leiteira do Maranhão, os efeitos dessas Instruções Normativas se fizeram sentir efetivamente, a partir do ano de 2012, quando o Ministério Público Estadual-MPE iniciou uma campanha interinstitucional de combate ao leite e queijo “clandestinos”, produzidos em estabelecimentos sem registro formal nos órgãos de fiscalização sanitária. Como consequência desta campanha, observou-se uma reconfiguração do mercado de leite regional, com a modificação das relações comerciais entre os produtores primários de leite e as unidades de beneficiamento formais (indústrias de laticínios) e informais (queijarias), tendo, os laticínios, assumido a posição de defensores da implantação das Instruções Normativas, enquanto os demais atores procuram flexibilizar a aplicação das mesmas. Situado no campo da Sociologia Econômica, este estudo buscou abordar a problemática em questão, orientando-se pelas ideias de que os processos de estabelecimento de critérios de qualidade constituem um momento preliminar ao estabelecimento do intercâmbio mercantil, e que, a qualidade de um produto não se define a partir de uma referência universal, mas a partir de valores socialmente compartilhados, pautados em diferentes noções de “justiça” e “bem comum”. A partir do modelo das cités, elaborado por Boltanski e Thévenot (1991), foi possível identificar na região estudada, dois modelos de produção e beneficiamento de leite em disputa, correspondendo conceitualmente aos modelos das convenções do mundo doméstico e do mundo industrial, representados, respectivamente, pelos produtores identificados como queijeiros e pela indústria de laticínios. Neste sentido, estes dois mundos foram descritos e analisados, buscando-se apreender os princípios e critérios de avaliação mobilizados pelos atores envolvidos em situações caracterizadas por disputas em torno dos padrões de qualidade. De modo mais específico, o leite, o actante (CALLON, 2006) mais presente na cadeia estudada, foi seguido em sua trajetória para se transformar em queijo, ora quando levado pelas mãos da indústria de laticínios, ora pelas mãos das queijarias, revelando nestes percursos, os atributos dos actantes humanos e não humanos envolvidos nos processos de beneficiamento, as justificativas e os debates ideológicos que emergem nestes contextos, as diferenças nas formas de verificação e controle inerentes a cada uma delas, e os fatores que compõem os quadros cognitivos em cada mundo. Estes procedimentos permitiram, por fim, sumariar os principais impactos e consequências do processo de disputa pela qualidade e o estabelecimento de uma nova configuração para o mercado de leite, na MRH de Imperatriz.

Dans une situation de forte vulnérabilité induite par les crises laitières de 2009 et 2014-2016, de nombreux éleveurs laitiers se convertissent à l’AB qui semble une alternative prometteuse. Mais la conversion à l’AB est une période de changements de pratiques agricoles, d'interlocuteurs de conseil, etc. sources d’incertitudes sans valorisation immédiate du lait au prix du lait AB avant 1 an ½ à 2 ans. Ce choix de conversion pose la question de la vulnérabilité des exploitations laitières, c’est à dire de leur capacité à faire face, à s’adapter ou à se remettre des effets de divers aléas avant, pendant et à l’issue de la conversion à l’AB. Ma thèse visait à évaluer si la conversion à l’AB est un moyen de réduire la vulnérabilité des exploitations laitières. Pour ce faire, je me suis appuyée sur trois dispositifs de suivis d’éleveurs laitiers à différents moments de leur conversion à l’AB. Au plan de la production de connaissances, ce travail montre que la conversion à l’AB peut être un levier important pour la réduction de la vulnérabilité des exploitations agricoles à condition de s’orienter vers un système à dominante herbagère. Au plan méthodologique, la principale originalité de mon travail réside dans le développement d’une méthode d’évaluation intégrée et dynamique de la vulnérabilité. / In a situation of high vulnerability induced by the 2009 and 2014-2016 milk crises, many dairy farmers convert to organic farming, which seems a promising alternative. But the conversion to organic farming is a period of changes in farming practices, farm consultants, etc. sources of uncertainties without immediate valuation of the milk at the organic price before 1 ½ to 2 years. This conversion decision raises the question of the vulnerability of dairy farms, i.e. their ability to cope with, adapt to or recover from the effects of various hazards before, during and after the conversion. My PhD project aimed to assess whether the conversion to organic farming is a way to reduce the vulnerability of dairy farms. To that end, my work relied on three research set-ups based on surveys with dairy farmers at different stages of their conversion to organic farming. In terms of knowledge production, this work shows that conversion to organic farming can be an important lever to reduce farms vulnerability, as long as they move towards pasture-based system. In terms of methodological production, the main originality of my work lies in the development of an integrated and dynamic method for vulnerability assessment.

Agriculture is key to New Zealand�s economy with land-use conversions in response to market forces occurring regularly. Recently, high-intensity dairy farming has replaced low-density livestock farming, often degrading surrounding waterways. Of particular concern is that dairy cattle can be a source of the parasite Giardia, which in humans is a common cause of gastrointestinal infection. Thus, this thesis evaluated whether dairy farm conversions posed significant consequences for public health. First I examined the prevalence of Giardia in calves in a rapidly intensifying dairying region of New Zealand. A total of 1190 faecal samples were collected from calves one to seven weeks old during two spring calving seasons and screened by direct immunofluorescent microscopy. Giardia cysts were detected in 31% of samples. To evaluate the potential risk that this environmental source of Giardia posed to the human population, molecular genotyping was used to compare forty Giardia strains isolated from calves with thirty isolates from humans collected in the same region and period. Sequencing the β-giardin gene, Giardia duodenalis assemblages A and B were identified from both hosts, with genotype comparisons revealing substantial overlap of identical genotypes for both assemblages, implying zoonotic transmission. Environmental agencies routinely promote the planting of streamside edges to decrease nonpoint pollution from dairy farms entering waterways. However, current methods for tracking pathogens across farmland and into waterways via surface runoff are limited and typically have been developed using artificially created landscapes. Furthermore, no studies have investigated how Giardia moves across the landscape in farm surface runoff. I developed a field-based tracking method specific for Giardia and used this technique to compare the ability of recently planted vegetation strips with bare soil strips cleared of vegetation at decreasing pathogen concentrations; a typical scenario when planting barriers to reduce waterway contamination. A spike containing a bromide tracer and inactivated Giardia cysts was applied in drip-irrigated surface runoff, with one-minute samples collected from the bottom of the plot. A significant treatment effect was identified for Giardia, with 26% fewer detected in runoff from the planted strip, highlighting the immediate benefit of vegetation planting in removing pathogens. Next I evaluated the effects of four riparian treatments on Giardia runoff: exotic pasture grass and weeds growing in the absence of cattle grazing due to fencing, in comparison to monocultural plantings of three New Zealand native grassland species. Runoff experiments were performed after planting, both prior to and following the main summer growing season. Bromide recovery was high from all four treatments (54 - 99%), with no significant treatment effects. By comparison, Giardia recovery was low (1 - 13%). Prior to summer, two native species reduced Giardia in runoff more than the pasture grass/weed treatment which was almost vegetation-free at this time. After summer, Giardia recoveries were uniformly lower in all treatments. These results demonstrate that after one growing season, fencing waterways produces riparian buffers, via the growth of exotic pasture plants released from grazing, that decrease pathogen concentrations in surface runoff to concentrations indistinguishable from native plantings. Given infectious organisms are known to be in the environment, it is important to assess the risk these pose to human populations. Findings from this research can be used to improve currently available risk-assessment models for Giardia transmission from infected dairy animals via water to humans.

The goal of this thesis was to develop a framework that could integrate and analyse industry-wide information for the support of on-farm decision-making in dairy-cattle breeding. Specific objectives included (i) describing a dairy breeding information system (DBIS); (ii) examining how the Internet could be exploited to improve the DBIS and its functioning; (iii) describing a process for implementing a unified data model to facilitate integrated user access to information in the DBIS; and (iv) developing software to support decision-making by facilitating access to a unified data model when implemented as a database management software. / The first objective was achieved by following a systems approach---defining a goal, boundary, functions, structure and performance---to describe multi-organisational information systems and, specifically, a DBIS in the Canadian dairy industry. Using this framework, the subsequent analysis of the DBIS looked at its overall effectiveness. The DBIS was also compared with other known systems, where the number of participants (as well as their roles) differs from the Canadian situation. Improvements were suggested for the Canadian DBIS by focussing on the decision-maker's ability to retrieve, integrate and consider required information through information technologies. The second objective involved using the systems approach to investigate the kinds of information (if any) provided on Web sites of the DBIS participants, and to see if the Internet could be exploited to improve this process, either in terms of improved transfer speed or data transformation. It was established that the Internet is being used for rapid, flexible access to support information by DBIS participants, but that it is being under-utilised, particularly where herd output information is concerned. Herd output information could be filtered, integrated and transformed to support specific user needs at appropriate levels of intelligence density. It was further postulated that these data could be exploited more effectively through the use of such information technologies as common data exchange mechanisms and decision-support systems. The third objective was achieved through applying information engineering methods to develop a data model to represent the DBIS. This unified model was described in conceptual, logical and physical terms, and facilitated transparent access for on-farm users to information from more than one source organisation. It was demonstrated that such a model could maintain the autonomy of participating organisations while simultaneously creating an amalgamated databank for decisio

Summary: Swaziland has long had a disparity between the supply and demand of milk. Even at present milk production continues to be less than the market demand. The quantitative contribution of smallholder dairy farmers to local milk production remains unknown because of poor record keeping. This study was aimed at attaining a clear understanding of the dynamics of smallholder dairying in Swaziland, including the identification and understanding of the constraints faced by farmers in dairying, with the hope of devising workable solutions to them. A sample of 118 smallholder dairy farms were covered in this study, with a total herd of 306 lactating cows, comprising mainly of Jerseys and Holstein Friesians, with some cross breeds. There were no significant differences in mean milk yield/cow with respect to farmer gender (P > 0.05) and Agro-ecological zone location (P > 0.05) of the farms. Milking frequency had a significant effect on milk yield, since cattle milked once a day had lower (P < 0.05) milk yields than those milked twice a day. The cattle had extensively long calving intervals i.e. 448 ± 166 days, ranging from 292 to 1082 days. Low milk yield and poor reproductive performance of cattle were found to be mainly due to poor nutrition, breeding practices and stock quality. These are primarily a result of insufficient farmer training and inadequate technical assistance, scarce availability of quality stock, lack of investment resources and market support that includes favourable milk prices for farmers to make money. This performance of the Swazi smallholder dairy herd was then evaluated by comparing it to the performance of a larger, well-managed herd of known pedigree. Lactation records from 252 Jersey cows and 108 Holstein Friesian cows were obtained from Cedara Agricultural Research Institute, covering the periods; July, 2002 to July, 2004 and November, 2002 to April, 2004, respectively. Cows were grouped by parity and calving season and the gamma function proposed by Wood (Y = An(b) e(-cn)) was used to fit standard lactation curves on group data. The curve parameters A and b increased with parity, while that of c and s (persistency of lactation at peak) decreased, producing standard lactation curves save for the Holstein Friesian summer calvers, which produced atypical curves. The R(2) values (goodness of fit) increased with parity. Animal parity and calving season were found to influence the peak and shape of the lactation curves and their parameter estimates. The performance of the Swazi smallholder herd showed a mean deviation of the observed daily milk yield of the Holstein Friesian breed from the expected yield to be - 3.47 (SD 6.052) kg and that of the Jersey breed was - 16.92 (SD 5.473) kg. The mean proportional deviation of observed milk yield from the expected yield for the Holstein Friesian breed was - 0.3 (SD 0.37) and that of the Jersey breed to be - 0.6 (SD 0.19). The proportional milk yield deviation of the Holstein Friesian breed can be explained using the equation Y = O.1322(SE = 0.1293) x - 2.3581 (SE = 0.20639), where x = expected milk yield and Y is the proportional deviation of the observed milk yield deviation from the expected milk yield. With respect to the smallholder Jersey breed, no relationship was found that could explain the proportional milk yield deviation. The smallholder herd was shown to be underperforming, considering the potential for higher milk yields of the two breeds. In the quest to gain a greater understanding of the dynamics of smallholder dairying, the sample of 118 farmers was further analysed using multivariate statistics to categorise them based on their herd sizes, herd structures, management and success perceptions in dairying. The analysis produced three clusters (categories): cluster 1 had the largest herd sizes and poor milk production efficiency; cluster 2 had intermediate herd sizes, the highest number of farmers and more efficient milk production per cow. This cluster, however, had the highest proportion of calf mortalities. Cluster 3 had the smallest herd size, the lowest calf to cow ratio and the second highest calf mortality. Record keeping across all clusters was very poor and the average milk yield per cow was generally low. Most of the farmers do not appreciate the importance of annual calving of their cows as an integral part of the success of their dairy projects and winter feed supplementation is very poor across all the clusters. There remains a great need for the enlightenment of the farmers on the importance of good nutrition, breeding, calf rearing and record keeping in successful dairying. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.

Poor estrus detection can limit the reproductive performance of a dairy herd. One objective of this research was to evaluate an alternative method to traditional estrus detection in the form of automated monitoring technologies. To accomplish this, the first study considered the ability of automatically monitored parameters (activity, number of steps, lying bouts, lying time, feeding time, rumination time, and temperature) to detect estrus. A second study compared automated activity monitoring to timed artificial insemination as reproductive management strategies on commercial herds. The other objective of this research was to evaluate the economic potential of automated estrus detection technologies. This was accomplished by creating and evaluating a farm specific decision support tool to determine the net present value of adopting an automated estrus detection technology.

More than 60% of the dairy products consumed in Swaziland are imported from South Africa. The Swaziland Dairy Board had established the dairy credit guarantee scheme with Swaziland Finance Development Cooperation to improve local dairy production and boost the livelihoods of smallholder dairy farmers. Unfortunately, the scheme was terminated without its effectiveness being evaluated. Therefore, the study set out to investigate the contribution of the dairy credit guarantee scheme to household food security. A total of 30 beneficiary households participated in the study. The data were collected through a structured questionnaire and analysed using the Statistical Package for Social Sciences (SPSS version 18.0). The households were compared in terms of the mean number of cows, milk production and volume of sales using the Duncan Multiple Range Test (DMRT). The dairy scheme was open to all qualifying smallholder dairy farmers, but most (86.7%) beneficiaries were male. The beneficiary households owned, on average, between one and eight cows between 2006 and 2009, and produced 188079 litres of milk on average per year. The highest income generated from milk sales was R74137.00 per year between 2006 and 2009. The lowest income from milk sales was R1020.00, from a household with the lowest number of dairy cows on average per year between 2006 and 2009. Beneficiaries reported that the increase in income enabled them to accumulate agricultural assets, increased food purchases and the diversification of livelihoods. Over 56.7% of the households were able to diversify their livelihoods by engaging in other income-generating projects such as poultry and pig production, horticulture, selling groceries and block (brick) making. With improved income especially milking households were able to increase food supply and this is indicated by their higher average Food Consumption Scores (75.58) than non-milking households (59.65). However, all the average Food Consumption Scores were above 42 which is a threshold level for acceptable nutrient intake, dietary diversity and this implies that the dairy production scheme led to improved dietary intake. In conclusion, the dairy credit scheme has the potential to improve local milk production and household food security. It is, therefore, recommended that the dairy scheme be revived, with better accessibility. The establishment of dairy development policy should be considered, in order to create a favourable environment for dairying and the promotion of cooperation among dairy development partners. This cooperation would help to avoid duplication of efforts among development partners and create a platform for interaction, sharing of information and exchange of ideas. / Thesis (M.Sc.Agric.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.

Agriculture is key to New Zealand�s economy with land-use conversions in response to market forces occurring regularly. Recently, high-intensity dairy farming has replaced low-density livestock farming, often degrading surrounding waterways. Of particular concern is that dairy cattle can be a source of the parasite Giardia, which in humans is a common cause of gastrointestinal infection. Thus, this thesis evaluated whether dairy farm conversions posed significant consequences for public health. First I examined the prevalence of Giardia in calves in a rapidly intensifying dairying region of New Zealand. A total of 1190 faecal samples were collected from calves one to seven weeks old during two spring calving seasons and screened by direct immunofluorescent microscopy. Giardia cysts were detected in 31% of samples. To evaluate the potential risk that this environmental source of Giardia posed to the human population, molecular genotyping was used to compare forty Giardia strains isolated from calves with thirty isolates from humans collected in the same region and period. Sequencing the β-giardin gene, Giardia duodenalis assemblages A and B were identified from both hosts, with genotype comparisons revealing substantial overlap of identical genotypes for both assemblages, implying zoonotic transmission. Environmental agencies routinely promote the planting of streamside edges to decrease nonpoint pollution from dairy farms entering waterways. However, current methods for tracking pathogens across farmland and into waterways via surface runoff are limited and typically have been developed using artificially created landscapes. Furthermore, no studies have investigated how Giardia moves across the landscape in farm surface runoff. I developed a field-based tracking method specific for Giardia and used this technique to compare the ability of recently planted vegetation strips with bare soil strips cleared of vegetation at decreasing pathogen concentrations; a typical scenario when planting barriers to reduce waterway contamination. A spike containing a bromide tracer and inactivated Giardia cysts was applied in drip-irrigated surface runoff, with one-minute samples collected from the bottom of the plot. A significant treatment effect was identified for Giardia, with 26% fewer detected in runoff from the planted strip, highlighting the immediate benefit of vegetation planting in removing pathogens. Next I evaluated the effects of four riparian treatments on Giardia runoff: exotic pasture grass and weeds growing in the absence of cattle grazing due to fencing, in comparison to monocultural plantings of three New Zealand native grassland species. Runoff experiments were performed after planting, both prior to and following the main summer growing season. Bromide recovery was high from all four treatments (54 - 99%), with no significant treatment effects. By comparison, Giardia recovery was low (1 - 13%). Prior to summer, two native species reduced Giardia in runoff more than the pasture grass/weed treatment which was almost vegetation-free at this time. After summer, Giardia recoveries were uniformly lower in all treatments. These results demonstrate that after one growing season, fencing waterways produces riparian buffers, via the growth of exotic pasture plants released from grazing, that decrease pathogen concentrations in surface runoff to concentrations indistinguishable from native plantings. Given infectious organisms are known to be in the environment, it is important to assess the risk these pose to human populations. Findings from this research can be used to improve currently available risk-assessment models for Giardia transmission from infected dairy animals via water to humans.

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