Most research to date has focused on non-pregnant sheep grazing saltbush to fill the summer/autumn feed gap in temperate regions of southern Australia. However, the summer/autumn period coincides with late pregnancy for autumn- or winter-lambing ewes, and feeding saltbush may reduce the amount and cost of supplementary feed that is required to meet the energy demands of late pregnancy. The challenge of dealing with a high-salt diet may be exacerbated during pregnancy since pregnancy is a salt-retaining physiological state, yet a high-salt intake requires an increase in mechanisms to excrete salt. The effect of high dietary salt on the developing foetus(es) has been studied in rodent models, but less so in sheep. Hence the aims of this thesis were to determine whether pregnant ewes can manage a high dietary salt content resembling that found in saltbush, and whether there are consequences to the offspring’s physiological responses to ingested salt. Merino ewes were synchronized for ovulation and artificially inseminated. To mimic the concentration of salt in animals grazing saltbush-based pastures in summer and autumn, a diet of 13% NaCl was fed from insemination through to parturition. It was found that pregnant ewes can be fed a 13% NaCl diet and manage the physiological conflict of high salt and pregnancy by decreasing their aldosterone concentrations and increasing their water consumption. There was no effect of high dietary salt on pregnancy rates, lamb birth weights, lamb survival or milk composition (fat and protein percentages). A series of experiments were conducted to test if the high-salt intake of ewes during pregnancy was associated with a change in the dietary preference for salt and/or changes in physiological responses to ingested salt in the offspring (‘S lambs’ vs. control, ‘C lambs’). C lambs and S lambs were exposed to short- and long-term preference testing to determine if there were differences in their voluntary selection for salt in their diet. There were no significant differences in dietary salt preference between C and S lambs. The lambs were subjected to salt 'challenges' (oral dose of 40 g NaCl in 25% w/v solution) from 3-10 months of age and their water intake, urinary output, sodium excretion and hormone concentrations were measured over the ensuing 23 hours, and compared against counterparts dosed with an equal volume of water without salt. Following the initial salt challenge further experiments were conducted with slight alterations; water intake was manipulated immediately following the salt challenge; two consecutive salt challenges, 8 hours apart, were administered; and C and S lambs were offered salty water (1.5% NaCl) over a period of two days. The results of these salt challenge experiments showed that C and S lambs excreted a salt load at a similar rate, but they differed in the magnitude of changes in water intake and hormone concentrations required to achieve sodium homeostasis. S lambs were able excrete sodium at the same rate as C lambs but without decreasing aldosterone concentrations to the same extent and whilst consuming 400 mL less water in the first two hours post challenge. The aldosterone results suggested a lowered responsiveness to aldosterone and the lower water consumption suggested an altered thirst threshold. The experiment in which water consumption was manipulated suggested that when the supply or access to fresh water is limited, the capacity to remove a salt load is likely to be less impaired in S lambs than C lambs; S lambs were able to excrete the salt load faster than the C lambs when the availability of drinking water was limited. From the experiment in which lambs were treated with two consecutive salt challenges, the rate of sodium excretion increased after the second dose, but there remained no difference in the rate of excretion between C and S lambs; all animals were able to excrete 95% of the administered dose of sodium within 23 hours. The final experiment in which animals were given salty water (1.5% NaCl) for a period of two days showed consistent results with the previous experiments for water consumption and aldosterone concentrations between C and S lambs. There was no difference in sodium excretion between C and S lambs. A novel finding was a markedly lower voluntary feed intake in S lambs than C lambs. Although mechanisms for this are unknown, it may have profound effects on the productivity of the animals. The experiments reported in this thesis provide new information of relevance to pregnant ewes grazing halophytic forages. It is apparent that they can withstand a high NaCl content typical, of a saltbush-based pasture. Further work is warranted to conclude whether high salt during pregnancy is (i) beneficial to the offspring in regards to a higher capacity to deal with excess salt under farming conditions and (ii) consistently associated with a lower voluntary feed intake of the offspring. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1290752 / Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2007.

La région de Katiola, située au centre de la Côte d’Ivoire est affectée par des variations climatiques. Cette région d’une superficie de 9452 kilomètres est à cheval sur deux bassins versants, à l’ouest le bassin du Bandama et à l’est le bassin du Comoé. Malgré le manque des ressources en eau, cette zone connaît une intense activité de mobilisation et d’utilisation des eaux : périmètres sucriers dans les localités de Tafiré, les parcelles de riz irriguées et activités pastorales à travers le département. Ce travail consiste à localiser les sites potentiels des puits et forages à l’aide de la géostatistique et de la télédétection. Des outils tel que les sondes géophysiques, permettent une compréhension des caractéristiques hydrogéologiques des formations. Une compréhension de la productivité des formations géologiques par l'étude des relevés de forages et de la télédétection peut permettre une meilleure compréhension des aquifères de ces formations. L’objectif de cette étude est de mettre en place des valeurs de référence devant servir comme outils de gestion, de surveillance et voire même d’aide à la prise de décision. Egalement rentabiliser le coût des forages en proposant le maximum d’ouvrages avec beaucoup de chance de succès et établir un lien entre les formations et la circulation de l'eau souterraine (espacement, longueur, connectivité). Cette étude nous a présenté les potentialités que regorgent les images SRTM. Leur traitement nous a permis de faire une cartographie assez détaillée des limites de bassin versant, du réseau hydrographique, et d’établir l’ordre des cours d’eau selon Strahler. Le calcul de l’Index Topographique d’Humidité montre bien la corrélation entre la topographie, les sols et la qualité des sols. Malgré l’étendue de notre zone d’étude, il a été possible de trouver une corrélation entre les indices topographiques, la répartition des champs et les caractéristiques du sol. Ces résultats nous ont permis d’avoir une nette amélioration de la classification des sols et l’occupation à partir d’image LANDSAT. Les images LANDSAT, nous ont également permis de suivre le phénomène d’eutrophisation et de disparition des plans d’eau de surface dont souffre le département. Nous avons pu établir l’ordre d’apparition des végétaux sur les plans d’eau, ceci jusqu'à la disparition totale du cours d’eau / The Katiola region, located in central Côte d'Ivoire, suffers climatic variations. This region has an area of 9,452 km². It is straddling two watersheds, the Bandama basin to the West, and the Comoé basin to the East. Despite the lack of water resources, this area is experiencing an intense mobilization and use of water: sugar stores in the localities of Tafiré, paddy fields and irrigated pastoral activities across the department. This work aims to locate potential sites for drilling wells using eostatistics and remote sensing. An understanding of the productivity of geologic formations by studying the records of boreholes and remote sensing can provide a better understanding of the aquifers in these formations. The objective of this study is also to establish benchmarks to serve as management tools, monitoring and even aid in decision making. The goal is also to make a maximum of successful drillings, and establish a link between these informations (spacing, length, connectivity) and groundwater movements. This study presents the potential of the DEM SRTM images. Their processing llowed us to make a fairly detailed mapping of the boundaries of catchments, drainage network, and establish the order of watercourses according to the Strahler classification. The calculation of the Topographic Index Humidity shows the correlation between topography, soil and soil quality. Despite the size of our study area, it was possible to find a correlation between the topographic indices, the distribution of fields and soil characteristics. These results enabled us improving soil classification and occupation from LANDSAT imagery. Using LANDSAT images, we also monitored the eutrophisation and isappearance of surficial water bodies in the department. We could follow the order of appearance of plants on the water, until the total disappearance of the watercourse

Two experiments were conducted to examine the use of peppermint leaves and cinnamon oil on methane production and apparent ruminal digestibility. In experiment 1, 12 jars were utilized in a completely randomized design to conduct three separate 24 hour batch culture experiments. The objective of the batch culture experiments was to examine the effects of the selected natural supplements on methane production. For the first batch culture, jars were randomly assigned to one of the following treatments: 1) control diet (CON); 2) CON plus the addition of peppermint leaves at 3% of the diet (PEP3); 3) CON plus the addition of peppermint leaves at 6% of the diet (PEP6); or 4) CON plus the addition of peppermint leaves at 12% of the diet (PEP12). The addition of the peppermint leaves increased (P = 0.004) oxygen and tended to increase (P = 0.10) nitrogen gas, but had no significant (P ≥ 0.15) effect on methane production. For the second batch culture, jars were randomly assigned to one of the folloiwng treatments: 1) control diet (CON); 2) CON plus the addition of cinnamon oil at 125 mg/L (CIN 125); 3) CON plus the addition of cinnamon oil at 250 mg/L (CIN250); or 4) CON plus the addition of cinnamon oil at 500 mg/L (CIN500). Cinnamon oil decreased (P = 0.002) methane production when added at 500 mg/L which also decreased (P = 0.001) total gas production compared to the other treatments. For the final batch culture, jars were randomly assigned to one of the following treatments: 1) control diet (CON); 2) CON plus the addition of peppermint leaves at 3% of the diet and cinnamon oil at 125 mg/L (3:125); 3) CON plus the addition of peppermint leaves at 3% of the diet and cinnamon oil at 250 mg/L (3:250); or 4) CON plus the addition of peppermint leaves at 6% of the diet and cinnamon oil at 125 mg/L (6:125). The addition of the peppermint leaves at 6% of the diet and cinnamon oil at 125 mg/L significantly decreased nitrogen (P = 0.05) and methane (P = 0.0001) gas production compared to CON and 3:250 treatment. Based on the results of the three batch cultures, experiment 2 utilized four dual-flow continuous fermenters in a Latin Square design to examine the effects of the selected natural supplements on apparent ruminal digestibility and ruminal characteristics. Fermenters were randomly assigned to one of the following treatments: 1) control diet (CON); 2) CON plus the addition of peppermint leaves at 3% of the diet (PEP3); 3) CON plus the addition of cinnamon oil at 500 mg/L (CIN500); or 4) CON plus the addition of peppermint leaves at 6% of the diet and cinnamon oil at 125 mg/L (COMBO). Treatments for experiment 2 had no effect (P ≥ 0.17) on apparent ruminal digestibility of nutrients. There was no significant difference (P ≥ 0.09) in total or individual VFA concentrations, suggesting that the use of peppermint leaves, cinnamon oil, or a combination of the two has no adverse effects on apparent ruminal digestibility. Feeding ruminants a natural supplement such as cinnamon oil, peppermint leaves, or a combination could potentially reduce GHG production when feeding a low-quality, forage based diet.

Abiotic stress tolerance and biotic stress resistance have long been targets for trait improvement in the field of plant breeding. To date, much of the target crop focus has been centered on commodity crops such as corn, soybean, wheat, and rice. However, little work has been conducted on improvement of these traits in forage grasses. This is due to a number of issues, particularly that most species are obligately outcrossing, the traits are governed by many genes at unknown loci, and are greatly affected by environmental variation. This creates major complications in successfully selecting and breeding populations of forage grasses tolerant to extreme high or low temperatures, as well as disease resistance. Recurrent phenotypic selection was used to select elite individuals of annual ryegrass (Lolium multiflorum Lam.) and orchardgrass (Dactylis glomerata L.) that expressed improved germination at high temperature. Selections were conducted within growth chambers at fixed temperature and light regimes (40/30 DEGREES C, 12/12 hr, light/darkness) to eliminate environmental variation. Following three cycles of selection, we observed gains (P LESSTHAN 0.001) in selection over the base population for both species. Annual ryegrass mean cumulative germination for cycle 3 peaked at 45.8%, and orchardgrass mean cumulative germination for cycle 3 peaked at 82.67%. Further selection of annual ryegrass for freezing tolerance was also conducted. Flats of unselected germplasm were grown to the three-leaf stage, then frozen for nine hours. Significant differences (P LESSTHAN 0.05) in freezing tolerance were observed between selected germplasm in both cycle 1 (0.076%) and cycle 2 (0.125%) over the unselected cycle 0 (0.025%). Finally, initial stages of resistance breeding work were conducted involving gray leaf spot (causal agent Pyricularia grisea Cke. [Sacc.]) on annual ryegrass. Isolates of the pathogen were obtained and stored for future use. It was determined that the actual pathogen species responsible was Pyricularia oryzae Cavara. Future work for annual ryegrass and orchardgrass germplasm that germinates at high temperatures will involve variety testing and cultivar release. Freezing tolerance and disease resistance work will require larger-scale screening methodology that was able to be conducted in this work to acquire sufficient population sizes for breeding.

O enxofre é um dos elementos essenciais para as plantas e as exigências nutricionais nesse nutriente variam com a espécie e a taxa de crescimento das plantas. Com o objetivo geral de avaliar o efeito da nutrição em enxofre no crescimento e no metabolismo do capimtanzânia (Panicum maximum cv. Tanzânia) e do estilosante (Stylosanthes guianensis cv. Mineirão) desenvolveu-se a presente pesquisa com os objetivos específicos de avaliar os efeitos do fornecimento de enxofre em: i) modificações morfológicas, produtivas e nutricionais ocorridas na parte aérea e nas raízes; ii) metabolismo do nitrogênio e as consequentes alterações na composição e concentrações de aminoácidos; iii) concentrações de enxofre total, enxofre-sulfato e glutationa e na atividade das enzimas glutationa redutase e glutationa sulfo-transferase nas folhas recém-expandidas e raízes; iv) crescimento, metabolismo da glutationa e atividade das enzimas envolvidas no ciclo ascorbato-glutationa e v) absorção de sulfato e a expressão de genes de transportadores de sulfato. Os experimentos foram conduzidos em casa de vegetação e camara de crescimento, empregando-se soluções nutritivas. As doses de enxofre aplicadas foram ajustadas de modo a permitir nutrição baixa, intermediária e alta em enxofre para cada espécie. O enxofre afetou diretamente na emissão de folhas e de perfilhos, área foliar, comprimento e superfície radicular do capim-tanzânia e do estilosante Mineirão, aumentando a produção de massa seca da parte aérea e das raízes. A baixa disponibilidade de enxofre ocasionou o desequilíbrio nutricional com o nitrogênio nas plantas, evidenciado por alta relação nitrogênio:enxofre e altas concentrações de nitrato e aminoácidos livres no tecido vegetal. Sob limitação de enxofre, o capim apresentou predomínio de asparagina na composição aminoacídica, enquanto no estilosante ocorreu a predominância de arginina. A aplicação de enxofre aumentou as concentrações de enxofre total, enxofre-sulfato e glutationa nas folhas diagnósticas e raízes para ambas as espécies forrageiras. As plantas crescidas sob limitação de enxofre apresentaram alta atividade da enzima glutationa redutase visando regenerar a glutationa reduzida, que atua protegendo as células contra danos oxidativos decorrentes do estresse da deficiência nutricional. O fornecimento de enxofre aumentou a atividade da glutationa sulfo-transferase incrementando a capacidade do vegetal de suportar estresses ambientais. A baixa disponibilidade de enxofre induziu o aumento da atividade de enzimas antioxidantes que atuam na regeneração da glutationa e do ascorbato na forma reduzida. As plantas crescidas em baixa disponibilidade de enxofre apresentaram aumento da concentração de glutationa e maior alocação desse composto nas raízes. A distribuição de glutationa das folhas para as raízes em condição de limitação de enxofre regula a absorção de sulfato no capim e no estilosante de modo diferenciado. Para o capim com alta concentração de glutationa nas raízes decresce o influxo total de 34S, enquanto para o estilosante não ocasiona a redução da absorção de sulfato. / Sulfur is an essential element required by plants and the nutritional requirements in this nutrient vary according to species and plant growth rate. This research had the main objective of evaluating the effect of sulfur nutrition on growth and metabolism of Guinea grass (Panicum maximum cv. Tanzânia) and stylo (Stylosanthes guianensis cv. Mineirão) and was developed with the specific objectives to determine the effects on i) morphological, productive and nutritional changes in plant shoots and roots, ii) nitrogen metabolism and the changes in the composition and concentrations of amino acids, iii) concentrations of total sulfur, sulfur-sulfate and glutathione and the activity of the enzymes glutathione reductase and glutathione sulfo-transferase in recently expanded leaves and roots, iv) growth, glutathione metabolism and activity of enzymes involved in ascorbate-glutathione cycle and v) sulfate uptake and expression of sulfur transporters genes. The experiments were carried out in greenhouse and growth chamber, by using nutrient solutions. Sulfur supply were adjusted to low, intermediate and high S nutrition for each species. Sulfur supply influences the emission of leaves, tillering, leaf area, root length and surface of Guinea grass and stylo increasing production of dry mass of aboveground and roots. Sulfur limitation alters the distribution of photosynthates between aboveground and roots of Guinea grass and stylo providing reduction in dry matter production of roots. The plants of Guinea grass increase root surface as a mechanism for adaptation to limited S in the culture medium. The relative chlorophyll index (RCI) in the recently expanded leaves relates to the production of dry mass of aboveground and can be used to assess S nutritional status in Guinea grass and stylo. The application of S proves necessary to increase production of dry mass in Guinea grass and stylo. Low S availability caused nutritional imbalance with N in Guinea grass and stylo plants, as shown by a high N:S ratio and high concentrations of N-nitrate and free amino acids in plant tissues. Among amino acids, asparagine predominated in S-limited guineagrass and arginine in Slimited stylo. Increased S supply regulates N:S ratio at values close to 20:1, which provides N and S concentrations that are more suitable for protein synthesis and forage production in plants of both species. Adding S increased concentrations of total S, S-sulfate, and glutathione in diagnostic leaves and roots of both species collected at the two harvests. Plants grown under S limitation showed high levels of GR activity, related to the regeneration of GSH, which acts to protect cells against oxidative damage caused by the stress of nutritional deficiency. S supply increased GST activity, and consequently plants\' capacity to withstand environmental stresses. Low S availability increased activity of the antioxidant enzymes that act in the regeneration of GSH and AsA. Plants grown with low S availability showed higher concentration of glutathione and greater allocation of glutathione to roots. For Guinea grass, high glutathione concentrations in roots decrease the 34S uptake. For stylo not cause reduction of 34S uptake.

O enxofre é um dos elementos essenciais para as plantas e as exigências nutricionais nesse nutriente variam com a espécie e a taxa de crescimento das plantas. Com o objetivo geral de avaliar o efeito da nutrição em enxofre no crescimento e no metabolismo do capimtanzânia (Panicum maximum cv. Tanzânia) e do estilosante (Stylosanthes guianensis cv. Mineirão) desenvolveu-se a presente pesquisa com os objetivos específicos de avaliar os efeitos do fornecimento de enxofre em: i) modificações morfológicas, produtivas e nutricionais ocorridas na parte aérea e nas raízes; ii) metabolismo do nitrogênio e as consequentes alterações na composição e concentrações de aminoácidos; iii) concentrações de enxofre total, enxofre-sulfato e glutationa e na atividade das enzimas glutationa redutase e glutationa sulfo-transferase nas folhas recém-expandidas e raízes; iv) crescimento, metabolismo da glutationa e atividade das enzimas envolvidas no ciclo ascorbato-glutationa e v) absorção de sulfato e a expressão de genes de transportadores de sulfato. Os experimentos foram conduzidos em casa de vegetação e camara de crescimento, empregando-se soluções nutritivas. As doses de enxofre aplicadas foram ajustadas de modo a permitir nutrição baixa, intermediária e alta em enxofre para cada espécie. O enxofre afetou diretamente na emissão de folhas e de perfilhos, área foliar, comprimento e superfície radicular do capim-tanzânia e do estilosante Mineirão, aumentando a produção de massa seca da parte aérea e das raízes. A baixa disponibilidade de enxofre ocasionou o desequilíbrio nutricional com o nitrogênio nas plantas, evidenciado por alta relação nitrogênio:enxofre e altas concentrações de nitrato e aminoácidos livres no tecido vegetal. Sob limitação de enxofre, o capim apresentou predomínio de asparagina na composição aminoacídica, enquanto no estilosante ocorreu a predominância de arginina. A aplicação de enxofre aumentou as concentrações de enxofre total, enxofre-sulfato e glutationa nas folhas diagnósticas e raízes para ambas as espécies forrageiras. As plantas crescidas sob limitação de enxofre apresentaram alta atividade da enzima glutationa redutase visando regenerar a glutationa reduzida, que atua protegendo as células contra danos oxidativos decorrentes do estresse da deficiência nutricional. O fornecimento de enxofre aumentou a atividade da glutationa sulfo-transferase incrementando a capacidade do vegetal de suportar estresses ambientais. A baixa disponibilidade de enxofre induziu o aumento da atividade de enzimas antioxidantes que atuam na regeneração da glutationa e do ascorbato na forma reduzida. As plantas crescidas em baixa disponibilidade de enxofre apresentaram aumento da concentração de glutationa e maior alocação desse composto nas raízes. A distribuição de glutationa das folhas para as raízes em condição de limitação de enxofre regula a absorção de sulfato no capim e no estilosante de modo diferenciado. Para o capim com alta concentração de glutationa nas raízes decresce o influxo total de 34S, enquanto para o estilosante não ocasiona a redução da absorção de sulfato. / Sulfur is an essential element required by plants and the nutritional requirements in this nutrient vary according to species and plant growth rate. This research had the main objective of evaluating the effect of sulfur nutrition on growth and metabolism of Guinea grass (Panicum maximum cv. Tanzânia) and stylo (Stylosanthes guianensis cv. Mineirão) and was developed with the specific objectives to determine the effects on i) morphological, productive and nutritional changes in plant shoots and roots, ii) nitrogen metabolism and the changes in the composition and concentrations of amino acids, iii) concentrations of total sulfur, sulfur-sulfate and glutathione and the activity of the enzymes glutathione reductase and glutathione sulfo-transferase in recently expanded leaves and roots, iv) growth, glutathione metabolism and activity of enzymes involved in ascorbate-glutathione cycle and v) sulfate uptake and expression of sulfur transporters genes. The experiments were carried out in greenhouse and growth chamber, by using nutrient solutions. Sulfur supply were adjusted to low, intermediate and high S nutrition for each species. Sulfur supply influences the emission of leaves, tillering, leaf area, root length and surface of Guinea grass and stylo increasing production of dry mass of aboveground and roots. Sulfur limitation alters the distribution of photosynthates between aboveground and roots of Guinea grass and stylo providing reduction in dry matter production of roots. The plants of Guinea grass increase root surface as a mechanism for adaptation to limited S in the culture medium. The relative chlorophyll index (RCI) in the recently expanded leaves relates to the production of dry mass of aboveground and can be used to assess S nutritional status in Guinea grass and stylo. The application of S proves necessary to increase production of dry mass in Guinea grass and stylo. Low S availability caused nutritional imbalance with N in Guinea grass and stylo plants, as shown by a high N:S ratio and high concentrations of N-nitrate and free amino acids in plant tissues. Among amino acids, asparagine predominated in S-limited guineagrass and arginine in Slimited stylo. Increased S supply regulates N:S ratio at values close to 20:1, which provides N and S concentrations that are more suitable for protein synthesis and forage production in plants of both species. Adding S increased concentrations of total S, S-sulfate, and glutathione in diagnostic leaves and roots of both species collected at the two harvests. Plants grown under S limitation showed high levels of GR activity, related to the regeneration of GSH, which acts to protect cells against oxidative damage caused by the stress of nutritional deficiency. S supply increased GST activity, and consequently plants\' capacity to withstand environmental stresses. Low S availability increased activity of the antioxidant enzymes that act in the regeneration of GSH and AsA. Plants grown with low S availability showed higher concentration of glutathione and greater allocation of glutathione to roots. For Guinea grass, high glutathione concentrations in roots decrease the 34S uptake. For stylo not cause reduction of 34S uptake.

O desempenho animal pode ser melhorado pelo incremento na digestibilidade dos alimentos. Um dos elementos neste processo é a acurada caracterização da composição química. Objetivando avaliar quatro métodos para determinar o teor de lignina, foram estudadas cinco gramíneas: Brachiaria brizantha cv. Marandú, Brachiaria brizantha cv. Xaraés (MG-5), Panicum maximum cv. Mombaça, Pennisetum purpureum cv. Cameroon e Pennisetum purpureum cv. Napier. As frações fibrosas da parede celular (PC), fibra em detergente neutro (FDN) e fibra em detergente ácido (FDA) aumentaram conforme as plantas amadureceram, refletindo as mudanças na composição dos componentes da parede celular (celulose, hemicelulose e lignina). Os valores de PC foram superiores aos da FDN indicando solubilização da pectina e outros oligossacarídeos da parede celular na solução de detergente neutro. O método LDA apresentou os menores teores de lignina, evidenciando a solubilização de parte da lignina na solução de detergente ácido. Os resultados de LPer foram maiores que os de LDA, que pode ser devido à oxidação da celulose e pectina pelo permanganato de potássio. Os teores de LK foram maiores que os de LDA possivelmente por contaminação protéica, mas, menores que os de LPer. Os teores de LBA foram maiores que os outros três métodos. A digestibilidade acompanhou, de forma inversa, o estádio de maturidade das plantas. A digestibilidade in vitro apresentou forte correlação negativa com os teores de lignina para todos os métodos, menos para LPer. Encontrou-se um valor de relação de 2,23, entre os métodos LDA e LBA, que, ao ser aplicado, nos teores de LDA, resultou em reta similar ao da LBA. Chama a atenção como este valor de 2,23 é muito próximo ao 2,4 utilizado nas equações B2 e C das frações de carboidratos do \"Cornell Net Carbohydrate & Protein System\" e nas equações do National Research Counsil de 1996, para corrigir o teor de lignina. O método LBA é um método fácil e conveniente para determinar a concentração de lignina em forrageiras e uma boa opção para uso rotineiro nas análises de laboratório. / Animal performance can be improved by enhancing feed digestibility. One of the elements for this process is an accurate characterization of feedstuff chemical composition. With the objective of evaluating four methods used today for lignin determination, five grasses were used: Brachiaria brizantha cv. Marandú, Brachiaria brizantha cv. Xaraés (MG-5), Panicum maximum cv. Mombaça, Pennisetum purpureum cv. Cameroon e Pennisetum purpureum cv. Napier, All fibrous fractions, neutral detergent fiber (NDF), acid detergent fiber (ADF) and cell wall (CW), increased as the plants matured, reflecting the changes in the CW composition (cellulose, hemicellulose and lignin). The values obtained for CW were higher than those obtained for NDF, indicating solubilization of pectin and other cell wall oligosaccharides in the neutral detergent solution. The ADL method produced the lowest lignin values, reflecting lignin solubilization by the acid detergent solution. PerL results were higher than those of ADL, possibly due to hemicellulose and pectin oxidation by potassium permanganate. The values for KL were higher than those of ADL, possibly due to protein contamination, but were lower than PerL values. ABL values were the highest among all methods. Digestibility inversely followed plant maturity throughout the study. In vitro dry matter digestibility showed high negative correlation with lignin contents. A 2,23 ratio between ADL and ABL methods was found, which when applied to ADL values, resulted in a curve similar to ABL method curve. It is interesting to note that, this value of 2,23 is very close to the 2,4 used in carbohydrate fractions B2 and C of the \"Cornell Net Carbohydrate & Protein System\", for the correction of lignin content. The ABL method is easy and convenient for total lignin content determination in forages.

Orientadora: Telma Teresinha Berchielli Moreno / Banca: Euclides Braga Malheiros / Banca: Ives Cláudio da Silva Bueno / Resumo: Os sistemas de formulação de dietas para ruminantes exigem a avaliação de alimentos como forrageiras, pois essas são as principais fontes de nutrientes em condições tropicais. Por essa razão, é necessário o desenvolvimento de metodologias que sejam rápidas e ao mesmo tempo eficientes na avaliação de forragens para o funcionamento dos sistemas produtivos. O objetivo deste trabalho foi avaliar em duas épocas do ano o efeito de idade de corte (28, 35 e 42 dias), no valor nutritivo de três espécies forrageiras tropicais de grande utilização na alimentação de bovinos em pastejo no Brasil: capim-Tanzânia (Panicum maximum Jacq. cv. Tanzânia), o capim-Marandu (Brachiaria brizantha cv. Marandu), e o Tifton 85 (Cynodon spp), através da composição química, o fracionamento de proteína e carboidratos, a digestibilidade e a produção de gases in vitro. Nas duas épocas o Tifton 85 apresentou os maiores conteúdos de parede celular, fibra em detergente neutro (FON), fibra em detergente neutro corrigida para cinzas e proteína (FONcp), fibra em detergente ácido (FOA), lignina (LlG), carboidratos totais (CHOS totais), fração B2 e C dos carboidratos (69,36; 62,19; 32,09; 4,09; 78,31; 54,25 e 9,82%, respectivamente) e menores coeficientes de digestibilidade in vitro da matéria seca (OIVMS) e digestibilidade in vitro da matéria orgânica (OIVMO) 49,33 e 45,35% respectivamente, alem de menor produção de gases após 96h de incubação 225,49mL g-1 MS. O valor nutritivo (composição química, digestibilidade e produtos da digestão) da Brachiaria brizantha foi superior nas duas épocas do ano e nas idades de corte avaliadas nas condições deste trabalho comparada com Tanzânia e Tifton 85. / Abstract: In the tropics, diet formulation systems for ruminants require the forages evaluation, as they are the main source of nutrients for the animais. For this reason, the development of practical and efficient methodologies to evaluate forages is crucial for a better result of the production systems. The aim of the present work was to evaluate the cutting age effect (28, 35 and 42 days) in three different forage species which are largely used for the nutrition of cattle raised under pasture conditions in Brazil: Tanzania grass (Panicum maximum Jacq. cv. Tanzânia), Marandu grass (Brachiaria brizantha cv. Marandu) and Tifton 85 (Cynodon spp). compared based on the chemical composition, protein and carbohydrate fractions, digestibility and in vitro gas production of the forages. In the two different periods of the year Tifton 85 had the highest cellular wall components, neutral detergent fiber (NDF), neutral detergent fiber with corrections for mineral and protein (NDFcp), acid detergent fiber (ADF), lignin (LlG), total carbohydrates (CHOS), fraction B2 and C of the CHO (69,36; 62,19; 32,09; 4,09; 78,31; 54,25 e 9,82%, respectively), and the lower in vitro dry matter digestibility (IVDMD) 49,33%, in vitro organic matter digestibility (IVOMD) 45,35%, and the gas production 225,49mL g-1 MS. The forage nutritive value (the potential degradability (PD), the effective degradability (ED). Considering the two periods of the year and the three cutting ages investigated in the present study, the nutritive value (chemical composition, digestibility and nature of digested products) of Marandugrass was superior in comparison to Tanzaniagrass and Tifton 85. / Mestre

Submitted by Erika Demachki (erikademachki@gmail.com) on 2014-08-26T20:18:54Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação Mestrado COMPOSIÇÃO E PRODUTIVIDADE DO MILHETO EM TRÊS DENSIDADES DE SEMEADURA E DUAS ALTURAS DE CORTE - Josilene.pdf: 980825 bytes, checksum: 8434d3552e5561e788843f0e0c3f374c (MD5) / Made available in DSpace on 2014-08-26T20:18:54Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação Mestrado COMPOSIÇÃO E PRODUTIVIDADE DO MILHETO EM TRÊS DENSIDADES DE SEMEADURA E DUAS ALTURAS DE CORTE - Josilene.pdf: 980825 bytes, checksum: 8434d3552e5561e788843f0e0c3f374c (MD5) Previous issue date: 2013-10-10 / To evaluate the chemical composition and production of pearl millet (Pennisetum glaucum (L.)) at different sowing densities and managed under different cutting heights, a field trial was carried out at Santa Rosa do Rochedo farm of Universidade Federal de Goiás Campus Jatai, from March to July (second-season) after soybean harvest. A completely randomized block experimental design in factorial arrangement (3x2) with three sowing densities (10, 15 and 20 kg.ha-¹) and two cutting heights (50 and 70 cm) was used. Data were analyzed with SAS® v.9.2 program (SAS Institute Inc., Cary, NC) considering density effect and block in the plot and height in the subplot. Tukey test at 5% probability was used for mean comparison. The sowing density affected (P<0.05) CP percentage (13.98, 13.07 and 12.73 for 10, 15 and 20 kg.ha-¹ densities respectively). The cutting height influenced (P <0.05) chemical composition and production when compared one cut of each height, lower values of NDF (60,3%), ADF (35,7%) and higher levels of MM (8,8) and NFC (15,5%) were observed at 50 cm height cut. There were no effect (P> 0.05) of sowing density and cutting height on total yield during the experimental period. Due the better nutritional quality with longer period of pasture utilization and lower deployment cost, the use of pearl millet for grazing in the southwestern Goiás is feasible at sowing density of 10 kg.ha-¹ and height cut of 50 cm. / Objetivando avaliar a composição bromatológica e produção de massa do milheto (Pennisetum glaucum (L.)) em diferentes densidades de semeadura e manejado em duas alturas de corte, foi realizado um experimento de campo na Fazenda Santa Rosa do Rochedo da Universidade Federal de Goiás Campus Jataí, no período de março a julho de 2012 (safrinha) após a colheita da soja. O delineamento experimental utilizado foi em blocos ao acaso em arranjo fatorial (3x2) com três densidades de semeadura (10, 15 e 20 kg.ha-¹) e duas alturas de corte (50 e 70 cm). Para a análise dos dados foi utilizado o Programa SAS versão 9.2 considerando o efeito de densidade e bloco na parcela e altura na subparcela. Na comparação das médias foi realizado o teste Tukey a 5% de probabilidade. A densidade de semeadura influenciou (P<0,05) o teor de PB 13,98, 13,07 e 12,73% para as densidades 10 e 15 e 20 kg.ha-¹ respectivamente. A altura de corte influenciou (P<0,05) na composição bromatológica e nas produções quando comparados um corte de cada altura, menores teores de FDN (60,3%), FDA (35,7%) e maiores percentagem de MM (8,8%) e CNF (15,5%) foram observados na altura de corte 50 cm. Não houve (P>0,05) efeito da densidade de semeadura ou da altura de corte na produção total do período experimental. Devido à melhor qualidade nutricional, com maior período de utilização da pastagem e menor gasto com sementes no plantio, viabiliza-se a utilização do milheto para pastejo na região Sudoeste de Goiás, na densidade de semeadura de 10 kg.ha-¹ com corte aos 50 cm de altura.

Submitted by Cátia Araújo (catia.araujo@unipampa.edu.br) on 2017-01-26T11:12:19Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Estudo da secagem de sementes de cevadilha vacariana (bromus auleticus trinius) em secador de leito fixo.pdf: 2385971 bytes, checksum: 8780d036b0d37c436fd1daa5a863e741 (MD5) / Approved for entry into archive by Cátia Araújo (catia.araujo@unipampa.edu.br) on 2017-01-26T11:12:38Z (GMT) No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Estudo da secagem de sementes de cevadilha vacariana (bromus auleticus trinius) em secador de leito fixo.pdf: 2385971 bytes, checksum: 8780d036b0d37c436fd1daa5a863e741 (MD5) / Made available in DSpace on 2017-01-26T11:12:38Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Estudo da secagem de sementes de cevadilha vacariana (bromus auleticus trinius) em secador de leito fixo.pdf: 2385971 bytes, checksum: 8780d036b0d37c436fd1daa5a863e741 (MD5) Previous issue date: 2015-07-24 / A estação de clima frio que ocorre no Sul do Brasil causa uma dormência fisiológica nas plantas que vegetam estes campos, paralisando o crescimento e o desenvolvimento que afeta diretamente a pecuária. A inserção de espécies forrageiras de estação fria vem determinando uma grande demanda por sementes de qualidade. Entre estas sementes, pode ser citada a espécie Bromus auleticus Trinius, que é uma gramínea, também conhecida popularmente como cevadilha vacariana, considerada uma espécie nativa, perene de hábito cespitoso e com crescimento hibernal. Com a procura pela obtenção de semente de melhor qualidade, a secagem artificial pode ser uma etapa crucial para contribuir no processo de germinação, uma vez que a tecnologia mais empregada atualmente apresenta dificuldades que vão desde a fase de produção no campo, onde as sementes são colhidas precocemente, até seu beneficiamento, pois a secagem natural depende de condições climáticas e muitas vezes apresentam perdas fisiológicas no produto final. A secagem artificial torna-se de suma importância na tecnologia de beneficiamento de sementes, pois permite a redução do teor de água em níveis adequados para armazenamento e comercialização. Em face disso, o presente trabalho teve como objetivo principal realizar um estudo sobre o processo de secagem de sementes de cevadilha vacariana (Bromus auleticus) em um secador de leito fixo com fluxo de ar paralelo. Para alcançar este objetivo, o trabalho foi dividido nas etapas de caracterização física e fisiológica das sementes quanto ao diâmetro de partícula, esfericidade, massa específica real, massa específica bulk, porosidade e germinação; observação das isotermas de dessorção para as temperaturas utilizadas nos ensaios de secagem das sementes in natura; análise do processo de secagem das sementes in natura em condições pré-estabelecidas; verificar estatisticamente, a partir de um planejamento experimental fatorial 2³ com tréplica no ponto central os ensaios de secagem, bem como suas influências nos índices de germinação e umidade final das sementes; avaliação do processo de reumidificação para as sementes que passaram pela operação de secagem natural; estudo das isotermas de dessorção das sementes de cevadilha vacariana reumidificas, e análise do processo de secagem das sementes reumidificadas. Os dados experimentais obtidos permitiram uma análise física, fisiológica e físico-química mais detalhada das sementes de cevadilha vacariana, uma vez que não há informações na literatura para este tipo de semente. Os resultados do estudo de secagem ficaram na faixa de 4 a 9 % em relação a umidade final em base úmida. No que se refere a germinação os valores encontrados ficaram na ordem de 23 a 58 %. Para estas duas respostas a temperatura foi a variável de maior influência. O estudo de reumidificação seguido de secagem mostrou ser eficiente, uma vez que permitiu elevar a germinação das sementes de cevadilha vacariana para ordem de 84,33 e 82 % referentes a melhor e pior condição obtidos pela secagem da semente in natura. / The cold weather season covering Southern Brazil causes a physiological dormancy in forage plants grow these fields paralyzing growth and development which directly affects livestock. The inclusion of the forage species of cold weather has indicated a high demand for quality seeds. Among these seeds it is possible to point out the genus Bromus auleticus Trinius. which is a type of grass also popularly known as “cevadilha vacariana” considered to be a native species, perennial, with a caespitose habit and wintry growth. With the demand for obtaining better quality seeds, artificial drying can be a critical step to increase the quality and germination of the seed, since the technology currently employed presents more difficulties ranging from the production phase in the field where the seeds are harvested early until its processing, once the natural drying depends on weather conditions and often presents physiological losses in the final product. The artificial drying becomes of high importance in seed production technology, because it allows the reduction of the moisture content at appropriate levels for storage and marketing. This research goal was to conduct a study on the drying process of Bromus auleticus in a fixed bed dryer with parallel airflow. In order to achieve this objective, the work was divided into the steps physical and physiological characterization of the seeds as the particle diameter, sphericity, real density, bulk specific mass, porosity and germination; observation of desorption isotherms for temperatures used in the drying tests of the seeds in nature; analysis of the natural drying process in seeds harvested directly from the field in pre-set conditions; statistically verify, from a factorial design with 2³ rejoinder at the midpoint drying trials as well as their influence on the final germination rates and humidity of oleander seed; evaluation of a rewetting process for the seeds that have gone through natural drying operation; study of desorption isotherms of remoistured seeds, and analysis of the drying process of remoistured seeds. Experimental data obtained so far permitted a physical, physiological and detailed physical-chemical analysis of Bromus auleticus seeds, since there is no data in the literature for this seed. Drying study results were in the range 4-9% compared to humidity-based moisture. Regarding to the germination values it was found at around 25 to 58%. For these two responses temperature variable it was the most influential. The rewetting study followed drying proved to be efficient, since it allowed to increase germination of the seeds of cevadilha vacariana for the order 84.33 and 82% concerning the best and worst condition obtained by drying the seed in nature