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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Análise da secagem de cornichão (Lotus corniculatus L.) em leito fixo com escoamento de ar paralelo

Kanaan, Akel Ferreira 03 September 2014 (has links)
Submitted by Andrea Pereira (andrea.pereira@unipampa.edu.br) on 2017-03-10T16:36:46Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Análise da Secagem de Cornichão-Akel FKanaan.pdf: 1613401 bytes, checksum: 62cca34779fa01d06bb57914687636da (MD5) / Approved for entry into archive by Andrea Pereira (andrea.pereira@unipampa.edu.br) on 2017-03-10T16:37:11Z (GMT) No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Análise da Secagem de Cornichão-Akel FKanaan.pdf: 1613401 bytes, checksum: 62cca34779fa01d06bb57914687636da (MD5) / Made available in DSpace on 2017-03-10T16:37:11Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Análise da Secagem de Cornichão-Akel FKanaan.pdf: 1613401 bytes, checksum: 62cca34779fa01d06bb57914687636da (MD5) Previous issue date: 2014-09-03 / A crescente necessidade da utilização de espécies forrageiras de estação fria na região sul do país vem determinando uma grande demanda por sementes de qualidade. Entre as leguminosas se destaca o cornichão (Lotus corniculatus L.), que é uma leguminosa forrageira oriundo da Europa e da região mediterrânea. Esta leguminosa forrageira tem na versatilidade a sua maior vantagem, visto que apresenta produção de forragem na primavera, no verão e no outono, possui resistência à seca e ao encharcamento temporário do solo e apresenta boa persistência da massa verde. Além disso, as sementes deste tipo de espécie podem ser misturadas com espécies de inverno, o que aumenta o rendimento da matéria seca, dá uma melhor distribuição da forragem ao longo do ano e agrega uma melhora na qualidade das pastagens. Apesar dessas vantagens, as sementes de cornichão comercializadas possuem ainda uma baixa qualidade. Esse fato é decorrente de um sistema de fiscalização ineficiente, associado à dificuldade de produção e beneficiamento do produto. Outro problema que o produtor de sementes desta espécie enfrenta é a dormência tegumentar, isto é, o revestimento da semente (tegumento) é impermeável e não permite que a água necessária para a germinação chegue ao interior da semente. Na literatura, diversos trabalhos têm relatado que cada vez mais há um aumento na demanda de sementes forrageiras em função do melhoramento do campo nativo e das pastagens cultivadas. Diante de um mercado tão promissor, a obtenção de sementes de melhor qualidade ainda apresenta dificuldades que vão desde a fase de produção no campo, onde as sementes são colhidas precocemente em relação ao ponto de maturidade fisiológica devido ao processo de perda natural, até seu beneficiamento, onde o processo de secagem apresenta-se como uma etapa limitante que necessita de uma atenção muito especial para evitar perdas fisiológicas no produto final. De um modo geral, a secagem é definida como a remoção, voluntária ou não, total ou parcial, de uma fase líquida ou gasosa de qualquer material através da transferência de calor e de massa. A secagem tem em sua essência a finalidade de assegurar a conservação de um produto por meio da redução do seu teor de água. No caso de materiais orgânicos, como é o caso de sementes, a redução no teor de água deve ser efetuada até o ponto em que a concentração de açúcares, ácidos, sais e outros componentes, sejam suficientemente elevados para reduzir a atividade de água e inibir, portanto, o desenvolvimento de micro-organismos. Na tecnologia de produção de sementes de alta qualidade a secagem é tida com uma das etapas de maior importância, pois permite a redução do teor de água em níveis adequados para o armazenamento e comercialização (12 a 15 % de umidade), preserva as sementes de alterações físicas e químicas induzidas pelo excesso de umidade, torna possível a manutenção da qualidade inicial durante o armazenamento e possibilita colheitas próximas da maturação fisiológica. Entretanto, o processo de secagem, seja ele qual for, deve acontecer de forma controlada e de maneira uniforme a fim de evitar elevados gradientes de umidade e temperatura no interior do material que podem provocar a perda da qualidade do produto final. De acordo com o que foi exposto, o presente trabalho de mestrado teve como objetivo realizar um estudo sobre o processo de secagem de sementes de cornichão (Lotus corniculatus L.) em um secador de leito fixo com fluxo de ar paralelo. Para alcançar tal objetivo, este trabalho foi dividido nas seguintes etapas: caracterização física e fisiológica das sementes, análise do processo de reumidificação das sementes, estudo das isotermas de dessorção das sementes reumidificadas e avaliação dos efeitos da variação da temperatura, da velocidade do ar e da altura da bandeja sobre a cinética de secagem e qualidade fisiológica do produto final. Os dados experimentais mostraram que os resultados obtidos para a umidade em base úmida das sementes secas ficaram na faixa de 5 % para as secagens realizadas a 60 °C e em aproximadamente 8 % para as secagens realizadas a 40 °C. No que se refere à germinação, os valores encontrados estão na ordem de 44 a 59 % para as secagens realizadas neste estudo. Dentre as secagens, a que obteve o maior valor de germinação, com valor de 59 %, foi a realizada na condição de T = 40 °C, v = 1,0 m/s e h = 1,0 cm. / The growing necessity for the use of cool-season forage species in the southern region of the country has indicated a high demand for quality seeds. Among the legumes, the birdsfoot trefoil (Lotus corniculatus L.) is a forage legume which is originated in Europe and in the Mediterranean region. This versatility in the forage legume has its biggest advantage, since it presents forage production in the spring, summer and autumn, is resistant to drought and temporary waterlogging and shows good persistence of green mass. Furthermore, seeds of such kind can be mixed with winter species, which increases the yield of dry matter, gives a better distribution of the material throughout the year and adds an improvement in the quality of pastures. Despite these advantages, the seeds of birdsfoot marketed still have a poor quality. This fact is a result of an inefficient system of monitoring and difficulties associated to production and processing of the product. Another problem is that the seed producer of this species is facing cutaneous numbness, that is, the seed coat (tegument) is impermeable and does not allow the water, necessary for germination to reache the interior of the seed. In the literature, several studies have reported that there is an increasing demand for an increase in forage seed due to the improvement of native grassland and cultivated pastures. Faced with such a promising market, obtaining better quality seed still presents difficulties ranging from the production phase of the field, where the seeds are harvested early in relation to physiological maturation due to the natural loss process until its processing where the drying process is presented as a limiting step that requires particular attention to avoid losses in physiological final product. In general, drying is defined as the removal voluntary or not, full or partial, of a liquid or gaseous phase of any material by the transfer of heat and mass. Drying has its essence in order to ensure the preservation of a product through reduction of water content. In the case of organic materials, such as seeds, reduction in water content must be performed to the extent that the concentration of sugars, acids, salts and other components are sufficiently high to reduce the water activity and inhibit, therefore, the growth of microorganisms. In the production of high quality seeds the drying technology is seen with one of the most important steps, since it allows reducing the water content suitable for storage and marketing levels (12 to 15% moisture), preserves the seeds from physical changing and chemical induced excess moisture, makes it possible to maintain the initial quality during storage and enables the next harvest physiological maturity. However, the drying process, whatever it may be, should occurs in a controlled and uniform manner in order to avoid high temperature and humidity gradients within the material that could result in loss of quality of the final product. Towards to it, this paper aimed to conduct a study on the drying of seeds of birdsfoot trefoil (Lotus corniculatus L.) in a fixed bed dryer with parallel air flow. To accomplish this goal, this study was divided into the following steps: physical and physiological seed characterization, analysis of rewetting seed process, study of desorption isotherms of the rewetted seeds and evaluation the effects of temperature, air velocity and the height of the tray on the drying kinetics and physiological quality of the final product. The experimental data showed that the results for the dry seeds of UBU were in the range of 5 % to drying carried out at 60 ° C and about 8% to drying carried out at 40 ° C. With regard to seed germination, the values are found in a range of 44 to 59% for the drying carried out in this study. The drying condition whom presented the highest germination value about 59 % was performed on T = 40 ° C, v = 1,0 m/s and h = 1,0 cm.
2

Beef Average Daily Gain and Enteric Methane Emissions on Birdsfoot Trefoil, Cicer Milkvetch and Meadow Brome Pastures

Pitcher, Lance R. 01 May 2015 (has links)
Conventional production of meat products from ruminant animals in the United States requires inputs including the cultivation and nitrogen fertilization of annual grains such as corn and barley, and transportation of cattle and grain to feedlots. Consumers have concerns about the impact of feedlot conditions on animal health, and about the implications of pharmaceutical inputs such as growth hormones and antibiotics on the environment and human health. These concerns have led to a growing interest in pasturefinished meat production by consumers. Such smaller-scale livestock production systems can be healthier and lower-stress for animals, are integrated into local food systems and are more transparent to consumers, and have higher potential profitability for producers than traditional ruminant production methods. There is a strong market for pasture-finished beef products, and prices for naturally or organically raised beef have remained well above feedlot-produced product prices. There is also concern about the impact of ruminant production on the environment, including air and water pollution from feedlot production and greenhouse gasses that are emitted from ruminant animals during feed digestion. This thesis project explored the potential of a beef production system based on perennial legumes, including the non-bloating legume birdsfoot trefoil (BFT; Lotus corniculatus L.) for producing meat products from cattle while reducing concentrate feeding and methane production. The condensed tannins that are produced by BFT bind proteins in the rumen but allow them to be digested in the abomasum and intestines, which in turn leads to better utilization of forage nutrients during the finishing period and higher gains or milk production. The higher digestibility of legumes compared with grasses reduces methane emissions in cattle both through higher digestibility of the forage and through direct impacts on methanogens operating in the rumen. As reported in this thesis, steers finished on BFT gained significantly more weight per day than steers fed another perennial forage legume, cicer milkvetch, but did not gain as rapidly as feedlot-fed steers. At the end of summer grazing, the blood plasma of pasture-fed steers was lower in saturated and omega-6 fatty acids and higher in transvaccenic and omega-3 fatty acids than the blood plasma of feedlot-fed steers. When beef cows grazed grass and legume pastures, enteric methane emissions were lower on the legume pastures than the grass pasture. These results demonstrate that, compared with other feed sources, perennial legume pastures used for cattle production can improve cattle gains and reduce environmental impacts.
3

Stem Development, Seeding Rate, and Establishment of Birdsfoot Trefoil (Lotus corniculatus) for Organic, Grazing-Based Dairies

Hunt, Sara 01 May 2014 (has links)
Three studies applicable to organic management and cultivation of birdsfoot trefoil (BFT, Lotus corniculatus L.) are presented here. The first is a histological analysis of lignification in BFT stems that supports recommendations to harvest BFT at approximately 6 weeks of regrowth, or early bloom. Lignification decreases digestibility and is correlated with high shear force required to break BFT stems. The sixth internodes from the base of 10 BFT and two alfalfa plants were sampled during 15 weeks of midsummer regrowth. The lignified xylary ring reached its maximum radial width by 7.5 weeks of regrowth, and full bloom was reached by 6.5 weeks of regrowth. The second study evaluated establishment of BFT, which competes poorly with weeds and produces low yields during establishment. At an organic, irrigated site in northern Utah the effects of autumn vs. spring seeding, seeding rates of 3, 7 20, and 34 kg pure live seed (PLS) ha-1 and use of a companion crop on 3 years of annual yields and foliar cover of mature stands were determined. First year yields increased linearly with seeding rate (P≤0.05). Use of a companion crop reduced first year yields, and did not reduce weed cover. Autumn seeding of BFT alone, following harvest of a summer crop, is recommended for irrigated production. The final study evaluated BFT establishment on five organic dairy farms in souther Idaho and northern Utah. Participating producers broadcast seeded 4-ha BFT pastures in the fall at a rate of 25 kg PLS ha-1. All farms achieved high BFT density, but only two farms had higher BFT than weed density. These two farms also had high BFT cover the spring following autumn seeding, and their pastures produced 6000 to 7600 kg of dry matter ha-1 by 20 June 2012 and supported grazing for the remainder of the summer. Establishment was enhanced by crop rotation and sprinkler irrigation.
4

Influence of Supplemental Legumes that Contain Tannins and Saponins on Intake and Diet Digestibility in Sheep Fed Grasses that Contain Alkaloids

Owens, Jacob Michael 01 December 2008 (has links)
My objectives were to determine if nutritional benefits occur when animals are offered foods with compounds -- alkaloids, saponins, and tannins - that are potentially complementary. I hypothesized that food intake and digestibility increase when lambs consume plants such as alfalfa ALF that contain saponins or birdsfoot trefoil (BFT) that contain tannins when the basal diet is endophyte-infected tall fescue (TF) or reed canarygrass (RCG) both of which contain alkaloids. I predicted that the nutritional status of lambs would be enhanced if basal diets of alkaloid-containing grasses were supplemented with ALF or BFT. Lambs fed a basal diet of either endophyte-infected TF or RCG ate more food and consequently digested more dry matter, energy and nitrogen when supplemented with ALF or BFT. Lambs ingested more dry matter and digested more nutrients when fed a basal diet of RCG than one of TF, and supplementing with ALF and BFT was more beneficial for lambs fed TF than for lambs fed RCG. Increased intake of digestible nutrients was due to greater intake when lambs were offered more than one food, not due to an increase in digestibility. In pen trials meant to complement the field trials, lambs were offered an alkaloid-containing (either gramine or 5-methoxy-N,N-dimethyltryptamine) total mixed ration and supplemented with a food that contained saponins or tannins. All rations were isocaloric (3.3Mcal/kg) and isonitrogenous (14% CP). Lambs fed a ration with either alkaloid and offered a food containing saponin digested approximately the same amount of dry matter, energy, nitrogen, and NDF as lambs not offered saponin. When lambs were fed a ration with either alkaloid and supplemented with food that contained tannins, tannin consumption adversely affected dry matter, energy, and NDF digestibility, but lambs offered food with tannins increased dry matter intake, and as a result, they digested the same amount of dry matter, energy, and NDF as lambs not offered the food with tannins. Lambs offered tannin digested and retained more nitrogen than lambs not offered tannin. These findings indicate a nutritional advantage for sheep eating mixtures as opposed to monocultures of foods with different profiles of secondary compounds and nutrients.
5

Forage Yield and Quality of Binary Grass-Legume Mixtures of Tall Fescue, Orchardgrass, Meadow Brome, Alfalfa, Birdsfoot Trefoil, and Cicer Milkvetch

Cox, Steven R. 01 May 2013 (has links)
Rising fertilizer prices have led a return to the use of grass-legume mixtures to reduce N costs and improve pasture productivity. The objective of this study was to determine optimal species combinations of binary grass-legume mixtures to improve forage production and pasture nutritive value in irrigated pastures of the Intermountain West. The study was conducted at the Utah State University Intermountain Pature Research Facility near Lewiston, UT. Tall Fescue (TF), Orchardgrass (OG), and meadow brome (MB) were grown with alfalfa (ALF), birdsfoot trefoil (BFTF), and cicer milkvetch (CMV) in legume-grass mixes and monocultures at planting ratios of 25:75, 50:50, 75:25. Grass monocultures were fertilized with 0 (0 N), 67 (67 N), or 134 kg N ha-1 (134 N). Forage was harvested four times each season during 2011-2012. Forage of the mixtures and monocultures from the first and third harvests was analyzed for crude protein (CP) and neutral-detergent fiber (NDF). Average forage production of the unfertilized TF, MB, and OG monocultures was 11.03, 9.76, and 8.10 Mg ha-1, respectively. TF-ALF, OG-ALF, and MB-ALF grass-legume mixes averaged 24.0, 35.0, and 41.0% higher forage production than their respective unfertilized grass monocultures. The grass-legume mixtures with the highest CP were MB-ALF 159, TF-ALF 159, and TF-OG-159 g kg-1 and average 59, 43 and 51% higher than their respective unfertilized grass monocultures. Likewise, the mixtures with the lowest NDF were OG-ALF 453 g kg-1, OG-BFTF 469 g kg-1, and MB-ALF 480 g kg-1. These mixtures had 10, 7, and 18% lower NDF than their respective unfertilized grass monocultures. Individual harvests had similarly higher yields and CP, with lower NDF for the mixtures than the unfertilized grass monocultures. The grass-legume mixture with the 50:50 planting ratio were most productive and had high forage quality. The grass-legume mixtures had similar forage production as the grass monocultures at 134 kg N ha-1. The grass-legume mixtures also had higher CP and lower NDF than the grass monocultures. Cicer milkvetch did not perform well in irrigated pastures. Grass-legume mixtures with ALF and BFTF can be used to replace commercial N while increasing forage nutritive value.

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