Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / Typescript. Vita. Includes bibliographical references (leaves 124-142). Also available on the Internet.

Typescript. Includes vita and abstract. Includes bibliographical references (leaves 132-142). Also available online.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 64-77). Also available via the Internet.

Tesis de grado Carrera de Ingenieria Agronomica, Universidad Mayor De San Andres, Facultad de Agronomia. / Abstract in Spanish and English.

Orientador: Marcelo Andreotti / Resumo: Os sistemas integrados de produção agropecuária (SIPAs) são alternativas para o restabelecimento da capacidade produtiva de pastagens cultivadas ou para produção de silagem na entressafra, garantindo sustentabilidade e a intensificação dos sistemas mistos de produção. O objetivo deste trabalho foi avaliar a produtividade da soja em sucessão a um sistema de integração lavoura pecuária sob palhada da rebrota de diferentes consórcios de milho para produção de silagem. O experimento foi conduzido em Selvíria-MS, num Latossolo Vermelho distrófico de textura argilosa, no ano agrícola 2016. O delineamento experimental foi de blocos casualizados em esquema fatorial 2x5, com quatro repetições. Os tratamentos foram constituídos de milho safrinha em consórcio com guandu-anão e milho safrinha em consórcio com Uruchloa brizantha cv Marandu e guandu-anão (Cajanus cajan), sendo este em 5 densidades de semeadura na entrelinha do milho (0, 6, 12, 18 e 24 sementes m-1). Após a colheita do material vegetal para ensilagem foi implantada a cultura da soja cv. BMX Potência RR de verão em sucessão utilizando o mesmo delineamento experimental dos consórcios, objetivando avaliar o efeito da palhada remanescente sobre o desempenho da cultura. Visando o adequado estado nutricional, crescimento da soja em sucessão ao milho para silagem, recomenda-se o consórcio antecessor de milho com capim Marandu e guandu anão na população de 12 sementes m-1. Do ponto de vista econômico, e de acordo com os índices de ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Crop livestock systems are alternatives for reestablishing the production capacity of cultivated pasture or silage production in the off-season, ensuring sustainability and intensification of mixed production systems. The objective of this work was to evaluate soybean yield in succession in a crop livestock integration system under straw from different consortia. The experiment was conducted in Selvíria-MS, in Oxisol in the agricultural year 2016. The experimental design was a randomized complete block in a 2x5 factorial scheme, with four replications. The treatments were composed of corn in no season in a consortium with pigeon pea dwarf and corn in no season in a consortium with Uruchloa brizantha cv Marandu and Cajanus cajan, being 5 densities of sowing in the corn interweave (0, 6, 12, 18 and 24 seeds m-1). After harvesting the plant material for silage the summer soybean crop was implanted in succession using the same experimental design of the consortia to evaluate the effect of the remaining straw on the performance of the crop. Aiming at the adequate nutritional status, soybean growth in succession to corn for silage, the predecessor consortium of corn with Marandu grass and dwarf pigeon pea in the population of 12 seeds m-1 is recommended. From the economic point of view, and according to the profitability indexes, considered to implant the soybean in succession to the predecessor consortium for the production of silage, it is recommended to realize the culture witho... (Complete abstract click electronic access below) / Mestre

Large animal species, such as cattle, sheep and pigs, have great potential value to scientific research. This is due to their physiological similarity to humans, meaning they make excellent disease models in addition to their inherent agricultural value. However, the efficiency with which such animals can be created has been a critical barrier to their use in bioscience. Research into creating genetically modified large animals has not progressed as rapidly as research on smaller mammals, such as mice, for two main reasons. Firstly, technologies such as pluripotent stem cells, which are well established in rodents, are lacking for large animals. Secondly, large animals cannot produce as many offspring within a given time frame as mice or rats. This, combined with the low efficiencies and lack of precision of current transgenic methods, severely reduces the likelihood of obtaining an animal with a desired genotype within a viable amount of time. Recently, new tools known as ’genome editors’ have been developed to facilitate genetic modification of animals. The vastly enhanced efficiency of these editors in comparison to previous gene targeting methods, combined with the fact that genome editors do not require marker genes to be used, mean that creating genetically modified livestock is now far more feasible. This thesis investigates whether two types of genome editor, TALENs and CRISPR/Cas9, can be used to produce genetically modified large animals for a range of applications. Genome editors were combined with interspecific blastocyst complementation techniques to produce chimeric rodents where the haematopoietic system is partially or fully derived from the donor cells. This work was carried out with a long-term aim of producing chimeric animals which could produce human organs suitable for transplantation. Initial blastocyst complementation experiments were carried out by injecting murine ESCs into wildtype rat blastocysts. One animal resulting from these injections showed chimerism in several tissues. Further experiments were carried out using rat ESCs and mouse blastocysts which were either Runx1-/- or Rag1-/-, however no additional chimeras were identified. In addition to these experiments, TALENs and sgRNAs were designed against Runx1 and Rag1 in sheep and pigs in order to create a large animal model for future blastocyst complementation experiments. Increasing animal productivity is a key step in meeting the demands of an increasing global population and tackling future food insecurities. TALENs and sgRNAs for use in the CRISPR/ Cas9 system were created to target the myostatin gene in sheep. Myostatin is a negative regulator of muscle growth and animals which acquire natural inactivating mutations in both myostatin alleles exhibit a well-characterised double-muscled phenotype, where total muscle mass is about 20% greater than that of a wildtype animal. Embryo microinjections were carried out using both types of genome editor and two edited lambs were produced, one from each editor. The TALEN-edited lamb was mosaic for a deletion of arginine 283 which, upon further analysis of the muscle, did not appear to cause a significant phenotype. The CRISPR-edited lamb was heterozygous for a 20bp deletion, causing the formation of a premature stop codon and severe truncation of the mature myostatin protein. Based on data from other myostatin-knockout animals, including the Belgian Blue cattle breed, this truncated protein is not thought to be functional. To determine if this is indeed the case, the CRISPR-edited lamb is now part of a breeding programme to amplify the edited allele. To discover if genome editors could be applied to create disease-resistant animals, the project focused on foot and mouth disease. Through a literature search and bioinformatic analysis of the bovine and porcine proteomes, three host genes which are cleaved by the virus were identified; eIF4A1, eIF4G1 and IKBKG. TALENs were designed to bind and cut at the FMDV protease cleavage sites in all three genes in order to disrupt protease cleavage and reduce viral replication by slowing viral disruption of the host translation and innate immune response pathways. Although none of the TALENs showed any signs of activity, this thesis sets out some potential directions for future work. In conclusion, this thesis shows that, despite some technical issues, genome editors are a promising technology for the creation of genetically modified livestock.

Livestock provide as much as one-third of all protein consumed by humans, but have a disproportionate and growing environmental impact. Livestock production occupies 50-75% of agricultural land, contributes 15% of anthropogenic greenhouse gas emissions, and drives agricultural expansion in the tropics through the global trade in animal feed. This thesis therefore evaluates two strategies for shrinking the environmental impact of the livestock sector. First, I evaluate the potential for food losses (i.e. foods which were intended for human consumption, but which ultimately are not directly eaten by people) to replace grain- and soybean-based pig feeds in Europe. While food losses have been included in animal feed for millennia, the practice is all but banned in the European Union, because of disease control concerns. Several East Asian states have in the last 20 years, however, introduced regulated systems for safely recycling food losses into animal feed. I combine data from multiple sources (including government reports, the animal science literature, and factory-floor data from South Korean swill-feed factories), and find that the introduction of East Asian practices for recycling food losses as animal feed could reduce the land use of EU pork (20% of world production) by one fifth, potentially saving 1.8 million hectares of agricultural land. This would also reduce 12/14 other assessed environmental impacts and deliver economic savings for pig farmers, as swill (cooked food losses) costs 40-60% less than conventional grain-based feeds. In a survey of pig farmers (n=82) and other agricultural stakeholders (n=81) at a UK agricultural trade fair, we found high support (>75%) for the relegalisation of swill. Support for swill feeding arose in part because respondents thought that swill would lower costs, increase profitability, and be better for the environment. Our results also confirmed the critical importance of disease control and consumer communication when considering relegalisation, as respondents who thought that swill would increase disease risks and be unpalatable to consumers were less supportive of relegalisation. Any new system for the use of swill will require careful design of regulation to ensure that heat-treatment is sufficient, and to reduce to a negligible level the risk of uncooked animal by-products entering feed. Our results suggest, however, that if such a system can be established, there would be multiple benefits and widespread support for its relegalisation. Second, I evaluated the potential to increase the productivity of cattle ranching in the Brazilian Amazon. While high hopes have been placed on the potential for intensification of low-productivity cattle ranching to spare land for other agricultural uses, cattle productivity in the Amazon biome (29% of the Brazilian cattle herd) remains stubbornly low, and it is not clear how to realize theoretical productivity gains in practice. I therefore (a) surveyed six on-the-ground initiatives which have been working with local farmers to improve cattle ranching, quantifying their farm practices, animal performance, and economic results; and (b) analysed the progress that has already been made in reconciling agriculture and forest conservation, by evaluating the impact of the flagship anti-deforestation policy, the priority list (Municípios Prioritários). The survey showed that cattle intensification initiatives operating in four states have used a wide range of technologies to improve productivity by 30-490%, while supporting compliance with the Brazilian Forest Code. Using two complementary difference-in-difference estimators, I then found no evidence for trade-offs between agriculture and forest conservation under the priority list; instead, reductions in deforestation in priority list municipalities were paired with increases in cattle production and productivity (cattle/hectare). The policy had no effect on dairy or crop production. Together, these results provide real-world evidence that increases in cattle production in Brazil do not need to come at the expense of the country’s remaining native vegetation.

Submitted by Lara Oliveira (lara@ufersa.edu.br) on 2018-06-12T17:59:52Z No. of bitstreams: 1 ClaudineteLLC_DISSERT.pdf: 939833 bytes, checksum: b9a6187312b041a8f6c3c588b2ed267f (MD5) / Made available in DSpace on 2018-06-12T17:59:53Z (GMT). No. of bitstreams: 1 ClaudineteLLC_DISSERT.pdf: 939833 bytes, checksum: b9a6187312b041a8f6c3c588b2ed267f (MD5) Previous issue date: 2012-02-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The integration crop-livestock is a system of use of the agricultural areas with management of crops and animals at same area, making possible, intensification of the use of the land, increasing the sustainable of the production systems and improving the profitability through the introduction of the tillage of annual pastures. The news inter-relations established with the presence of animals can make the soil the most complex. For this reason, techniques of management adapted for this system of production must be developed. This work analyzed the effect of the soil compaction, in function of the soil physical and mechanical characteristics in areas cultivated with corn and bean at the integration system crop-livestock. The experiment was managed at Riacho dos Cavalos- PB, in the period of March of 2011 October of 2011. The parameters of soil bulk density, structural void ratio and compression index of the soil were analyzed in the depths of 0.0 to 0.05m, 0.05 to 0.10m and 0.10 to 0.20m. The delineation in blocks at random was used in scheme factorial 2x4x3 with three repetitions. The results showed significant differences up for soil bulk density and structural void ratio. There was not increase of the soil bulk density as well as reduction of the soil structural void ratio with the bovine ones / A integração lavoura pecuária (ILP) é um sistema de uso das áreas agrícolas com alternância de culturas e animais na mesma área, possibilitando, a intensificação do uso do solo, aumentando a sustentabilidade dos sistemas de produção e melhorando a rentabilidade por meio da introdução do cultivo de pastagens anuais. As novas inter - relações estabelecidas com a presença de animais podem tornar o sistema solo mais complexo. Desta forma, devem ser envolvidas técnicas de manejo adequadas a esse sistema de produção. Diante do exposto, o objetivo da pesquisa foi avaliar o efeito da compactação do solo, em função das características físico – mecânicas em áreas cultivadas com milho e feijão submetidas ao sistema de integração lavoura - pecuária. O experimento foi conduzido no Sítio Barra, município de Riacho dos Cavalos – PB, no período de março a outubro de 2011. Os parâmetros de densidade do solo, índices de vazios estruturais índice de compressão do solo foram analisados nas camadas de 0,0 a 0,05m, 0,05 a 0,10m e 0,10 a 0,20m. O delineamento utilizado foi em blocos ao acaso, em esquema fatorial 2x4x3 com três repetições. Os resultados evidenciaram diferenças significativas da densidade do solo para as duas culturas (milho e feijão) e o índice de vazios estrutural foi significativo para o sistema de manejo cultura do milho, como para o manejo com animais na área cultivada com feijão no sistema lavoura-pecuária. Não houve aumento da densidade do solo bem como redução do índice de vazios estrutural com o pisoteio dos bovinosA integração lavoura pecuária (ILP) é um sistema de uso das áreas agrícolas com alternância de culturas e animais na mesma área, possibilitando, a intensificação do uso do solo, aumentando a sustentabilidade dos sistemas de produção e melhorando a rentabilidade por meio da introdução do cultivo de pastagens anuais. As novas inter - relações estabelecidas com a presença de animais podem tornar o sistema solo mais complexo. Desta forma, devem ser envolvidas técnicas de manejo adequadas a esse sistema de produção. Diante do exposto, o objetivo da pesquisa foi avaliar o efeito da compactação do solo, em função das características físico – mecânicas em áreas cultivadas com milho e feijão submetidas ao sistema de integração lavoura - pecuária. O experimento foi conduzido no Sítio Barra, município de Riacho dos Cavalos – PB, no período de março a outubro de 2011. Os parâmetros de densidade do solo, índices de vazios estruturais índice de compressão do solo foram analisados nas camadas de 0,0 a 0,05m, 0,05 a 0,10m e 0,10 a 0,20m. O delineamento utilizado foi em blocos ao acaso, em esquema fatorial 2x4x3 com três repetições. Os resultados evidenciaram diferenças significativas da densidade do solo para as duas culturas (milho e feijão) e o índice de vazios estrutural foi significativo para o sistema de manejo cultura do milho, como para o manejo com animais na área cultivada com feijão no sistema lavoura-pecuária. Não houve aumento da densidade do solo bem como redução do índice de vazios estrutural com o pisoteio dos bovinos / 2018-06-12

Submitted by Suelen Reis (suziy.ellen@gmail.com) on 2013-04-22T19:38:03Z No. of bitstreams: 1 Dissertacao Rodrigo Lopesseg.pdf: 6101495 bytes, checksum: b7c89ccd1c5eda9de5eec5c37b07bb18 (MD5) / Approved for entry into archive by Rodrigo Meirelles(rodrigomei@ufba.br) on 2013-05-24T11:27:10Z (GMT) No. of bitstreams: 1 Dissertacao Rodrigo Lopesseg.pdf: 6101495 bytes, checksum: b7c89ccd1c5eda9de5eec5c37b07bb18 (MD5) / Made available in DSpace on 2013-05-24T11:27:10Z (GMT). No. of bitstreams: 1 Dissertacao Rodrigo Lopesseg.pdf: 6101495 bytes, checksum: b7c89ccd1c5eda9de5eec5c37b07bb18 (MD5) Previous issue date: 2009 / Esta dissertação analisa o abastecimento de carne verde em Salvador, no século XIX, tendo como objetos principais de análise, a Superintendência do Matadouro Público da Bahia - criada em 1866, sob administração provincial e municipal - e a prática de atravessamento e formação de monopólio sobre o comércio de carne verde, referendados freqüentemente nas fontes documentais, como principais fatores responsáveis, pelo alto custo da carne vendida em Salvador. Para tanto, busca as origens das dificuldades que cercavam o abastecimento, nos caminhos percorridos pelos rebanhos, na fiscalização deficiente dos Registros de gado e nos abusos cometidos pelas pessoas que negociavam diretamente a carne verde no mercado de Salvador. / Salvador

Este trabalho objetivou analisar os benefícios econômicos gerados pelos sistemas de produção agropecuária mistos, e também, avaliar o resultado econômico do sistema de integração lavoura-pecuária em Tangará da Serra, sudoeste do Estado de Mato Grosso. Na primeira etapa, foi realizada uma revisão sistemática com artigos internacionais que obtiveram a análise do resultado econômico em sistemas de produção mistos em 16 países. Na segunda etapa, utilizou-se um modelo determinístico para avaliar a viabilidade econômica do sistema de agricultura convencional (Sistema I) versus o sistema de integração lavoura-pecuária (Sistema II) no sudoeste de Mato Grosso. Ainda, aplicou-se um modelo estocástico para analisar o risco dos Sistema I e II. Os resultados obtidos comprovaram a mitigação do risco econômico quando utiliza-se sistemas de produção mistos, como a integração lavoura-pecuária. Porém, indicam que as principais limitações para a expansão desse sistema é a exigência de fatores de produção e a gestão na empresa rural. / This study aimed to analyze the economic benefits generated by mixed agricultural production systems and also to evaluate the economic results of integrated crop-livestock system in Tangara da Serra, southwest of Mato Grosso State. In the first step, a systematic review was performed with international articles that have achieved the economic analysis results in mixed production systems in 16 countries. In the second stage, we used a deterministic model to evaluate the economic viability of the conventional farming system (System I) versus the integrated crop-livestock system (System II) in the southwest of Mato Grosso. Still, it was applied a stochastic model for analyzing the risk of system I and II. The results proved the mitigation of economic risk when used mixed farming systems, such as integrated crop-livestock. However, indicate that the main constraints to the expansion of this system is the requirement for factors of production and management in rural business.