For Virginia, the primary forage base is endophyte-infected tall fescue (Schedonorus phoenix (Scop.) Holub). However, the decreased animal performance and disorders caused by the presence of the fungal endophyte Neotyphodium coenophialum reduces its suitability for many forage-livestock producers. The endophyte, which is found in the inter-cellular space of tall fescue tissues, forms a mutalistic relationship with the plant and helps the fescue tolerate drought, insect predation, and grazing pressure. The production of toxic ergot alkaloids by the endophyte is associated with decreased performance of animals that graze endophyte infected tall fescue. The objective of the current experiment was to determine how tall fescue type (endophyte free vs novel endophyte) and orchardgrass-legume (alfalfa vs clover) mixture affect grazing behavior of weaned steers. Forty-eight weaned steers (218 ± 18 kg) were blocked by frame score (medium and large), and randomly assigned within block to four treatments with three replications in a 2x2 factorial design. Each treatment consisted of 2 paddocks with the combination of tall fescue and legume-orchardgrass mixture as follow: alfalfa-orchardgrass mixture (A)/E-, clover-orchardgrass mixture (C)/E- , A/E++ and C/E++. Each group of 4 steers had 24 h access to both tall fescue stand and legume-orchardgrass mixture. Botanical composition of paddocks was determined on d 0, and forage mass, sward height and nutritive value were determined on d 0, 17 and 33. Behavior of steers was scanned every 5 min on d 24 and 25 from 0700 to 1900. The proportion of legumes was higher (P = 0.001) in A paddocks(37 %) compared to C paddocks (6%), while the percent orchardgrass was lower (P = 0.040) in A (33 %) than C (53 %). The proportion of broadleaf and grassy weeds was higher (P = 0.013) in E- paddocks (11 %) as compared with E++ paddocks (3 %). Sward height and herbage mass were similar between treatments during the experiment (P > 0.05). Nutritive value (CP, NDF and ADF) did not differ between fescue paddocks (P > 0.05). However, within mixed swards, CP was higher and NDF was lower in A compared with C (P < 0.05). Acid detergent fiber was (P < 0.05) lower in A than C only on d 0 and 17. Average daily gain did not differ between treatments (P > 0.05). Steers spent higher (P = 0.002) proportion of the daylight time grazing in treatments with C (56 %) as compared with A (50 %), and in treatments (P = 0.023) with E++ (55 %) compared with E- (52 %). Time spent ruminating, idling and lying, as well as steps taken per day, did not differ between treatments (P > 0.05). Regardless of differences in weeds between E- and E++, these results indicate that fescue type affected grazing behavior of calves. Difference between mixed swards in proportion of ground cover with legumes and orchardgrass, as differences in nutritive value between A and C may have affected grazing behavior of calves between mixed swards, instead of a legume species effect within mixtures. / Master of Science

M.S.

The Southeastern United States offers a beneficial environment for stocker and cow-calf production. Abundant tall fescue grass offers a feed source that has been underutilized. These studies evaluated how nitrogen rate and source can affect yield and nutritional quality of fall stockpiled tall fescue, and how grazing methods impact weight gains, forage utilization, and forage nutritive value. The first study evaluated the impact of N rate and source on the yield tall fescue stockpiled for winter grazing. In mid-September, seven N sources (ammonium sulfate (AS), ammonium nitrate (AN), urea + Agrotain @ 2.1 l/Mg (AG2), urea + Agrotain @ 4.2 l/Mg (AG4), urea + Agrotain @ 6.3 l/Mg (AG6), Nutrisphere (NuS), and urea) were applied at 0, 45, 90, and 135 kg N/ha. Ammonium sulfate produced the highest nutritive values of all N sources. Only yield in 2012 was found to be influenced by N volatilization inhibitors; said products had no effect on nutritive value. The second study evaluated how grazing methods impact nutritive value, ADG, and utilization of tall fescue stockpiled for winter grazing. Three treatments (continuous grazing, moved once per week, and moved twice per week) were used. In year one, cattle moved once and twice per week showed significantly higher ADG (P < 0.05) than the continuous treatment. In year two, cattle that continuously grazed had higher ADG (P <0.05), than cattle moved once and twice per week. Cattle moved once and twice per week showed greater forage utilization (P < 0.05) than cattle that continuously grazed. / Master of Science

Tall fescue (Lolium arundinaceum) is the principal cool-season species within pastures of the southeastern USA and is known to have a mutualistic relationship with a fungal endophyte (Neotyphodium coenophialum) that produces the ergot alkaloids responsible for tall fescue toxicosis. Management of the reproductive growth of tall fescue is necessary, as the seedheads contain the highest concentrations of ergot alkaloids, and livestock have been documented to selectively graze these tissues. Recently, the herbicide Chaparral™ has been shown to be an effective method to prevent seedhead production in tall fescue pastures while also increasing steer gains at a low stocking rate. The objective of this study was to compare the impact of Chaparral on steer and pasture production under multiple grazing intensities (GI). Chaparral (0 and 140 g ha-1) and two levels of GI (low: 3300±250 kg ha-1 & moderate: 2500±250 kg ha-1) treatments were arranged in a factorial combination as RCBD with three replications. Tall fescue seedhead densities were decreased (P < 0.05) within the Chaparral-treated pastures, but efficiency of the inhibition varied slightly between growing seasons. Chaparral-treated pastures had lower (P < 0.05) forage availabilities and contained forage with higher (P < 0.05) concentrations of crude protein (CP) and in vitro digestible dry matter (IVDDM) during both growing season. Steers within the Chaparral-treated pastures and low GI treatment had higher average daily gains (ADG). Carrying capacities (CC) were lowest and highest within the Chaparral-low GI and control-moderate GI treatments, respectively. Estimates of CC were not different (P > 0.15) between the Chaparral-moderate GI and control-low GI treatments. The higher ADG compensated for the lower CC of the Chaparral and low GI treatments and resulted in no difference (P > 0.60) in total gain per hectare (GPH) between grazing intensities and herbicide treatments in 2011. In 2012, the GPH were higher within the control and moderate GI treatments due to a lessening in the magnitude of difference between the herbicide and GI treatments. The effects of these treatments for alleviating symptoms of tall fescue toxicosis were inconclusive due to the low levels of ergot alkaloids production.

Thesis (M.E.F.E.)--University of Canterbury, 2007. / Typescript (photocopy). Includes bibliographical references (p. 136-143). Also available via the World Wide Web.

Thesis (Master)--İzmir Institute of Technology, İzmir, 2005 / Includes bibliographical references (leaves.165-174).

Thesis (Master)--İzmir Institute of Technology, İzmir, 2005 / The questionnaires contained in these the volumes comprise forms implemented as part of the masters thesis, "Residental Satisfaction in high-rise buildings", defended in February 2005 in the Department of Architecture in the Graduate School of Engineering and Sciences at the Izmir Institute of Technology

Thesis (Ph. D.) -- University of Tennessee, Knoxville, 2006. / Title from title page screen (viewed on June 7, 2006). Thesis advisor: Thomas C. Mueller. Vita. Includes bibliographical references.

Orientador: Ulf F. Schuchardt / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-09T20:28:05Z (GMT). No. of bitstreams: 1 Sales_HenriqueJorgeSousa_D.pdf: 2216336 bytes, checksum: 8961d924bfe31e720b51411a6194bd10 (MD5) Previous issue date: 2007 / Resumo: Neste trabalho, estudamos a esterificação seletiva química e enzimática para a separação dos esteróis, ácidos resínicos e ácidos graxos do resíduo oleoso de madeira, o Crude Tall Oil (CTO). A reação de esterificação enzimática (Candida antartica, lípase do tipo B) foi otimizada utilizando-se um planejamento fatorial 2. Os fatores estudados foram o tempo de reação (h), a temperatura da reação (°C), o teor de catalisador (%), o teor de metanol (%) e o teor de água (%). Com o aumento da temperatura de 24 para 60 °C observamos uma redução média na taxa de conversão de 26,6 %. O aumento da percentagem de metanol de 5 para 15 % também apresentou um efeito negativo na taxa de conversão de 13,1 %; isso indica uma inativação térmica (com a aumento da temperatura) e uma inativação do sítio ativo da enzima pelo metanol. O aumento da porcentagem de água de 0 para 15 % e do tempo de reação de 6 para 24 h apresentou um aumento de 31,2 e de 8,1 %, respectivamente, para a conversão. A interação entre a água e o metanol apresentou um efeito positivo de 22,5 % sobre a conversão, sendo que a melhor condição foi a de efetuar a reação à baixa temperatura (24 °C) com altos teores de água (10-15%) e metanol (10-15%). A adição do metanol em duas etapas também favoreceu a reação, devido ao efeito de desativação que o metanol tem sobre a enzima. O processo foi implementado em produção, onde 13,7 tons de CTO foram esterificadas em um tanque de 25 m e, após 166 h de reação, o índice de acidez caiu de 153,5 para 57,4 mgKOH/g. Através das análises do teor de ácidos resínicos livres, constatamos a total esterificação dos ácidos graxos presentes no CTO. O catalisador enzimático foi adsorvido em polipropileno e foram produzidos dois catalisadores heterogêneos com 0,2 g/g e 0,5 g/g; a relação 0,2 g/g foi a que apresentou a melhor relação custo-benefício para as reações em batelada. O catalisador heterogêneo foi empacotado em uma coluna, e essa foi utilizada para os experimentos de esterificação contínua. O catalisador se mostrou estável por mais de 50 dias. Comparando a performance do processo enzimático x processo químico, o catalisador enzimático apresentou melhor produtividade e seletividade. O resíduo obtido pelo fracionamento em um evaporador thin film apresentou um alto teor de esteróis livres (1,83%) e esteróis esterificados (22,31%). A fração leve do CTO esterificado foi fracionada em uma coluna de destilação piloto. Com este novo processo, obtivemos ésteres metílicos com alto grau de pureza e isento de contaminação por ácidos resínicos. No processo de purificação por destilação, obtivemos ácidos resínicos com 72,3% de pureza. O processo de esterificação seletiva e de fracionamento do CTO foi patenteado pela Cognis do Brasil. / Abstract: A process for obtaining fatty acid alkyl esters, rosin acids an sterols from Crude Tall Oil was developed. As first process step, a chemical or enzymatic esterification has been proposed. It has been shown that the enzymatic esterification of crude tall oil is technically and economically feasible. A 2 experimental design, to optimize the enzymatic process, was done. The factors studied were; reaction time (h), temperature (°C), catalyst (%), methanol (%) and water (%). Increasing the temperature to 60 °C, the conversion decreased 26.6%. The use of high amount of methanol resulted on a conversion of 13.1%. The increase of reaction time and amount of water improved the conversion in 8.1 % and 31.2 %. The best conditions found were reaction time (24 h), temperature (25 °C), water (10-15 %) and methanol (10-15 %). Dosage of methanol must be used because with higher amount of alcohol occurs deactivation of the enzyme. The laboratorial scale experiments were successfully, transferred to a 25 m pumped reactor in the industrial plant. An acid value reduction from 153.5 to 57.4 in 166 hrs could be achieved. Using an immobilized biocatalyst, 0.2 g/g and 0.5 g/g, experiments in a stirred reactor have been performed. The best results were obtained with the 0.2 g/g catalyst system. The biocatalyst was used for successive batches. A continuous process in a column was successfully performed in laboratorial scale. The column was stable for more then 50 days in continuous operation. We compared the performance of enzymatic and chemical esterification. The enzymatic process has better productivity than the chemical process. The separation of the methyl esters and rosin acids from the sterol borates by thin film distillation produced a pitch with (1.83 %) of free sterols and (22.31 %) of total sterols. The separation of the methyl esters from the rosinic acids by distillation produced a high purity methyl ester free of resinic acids and a resinic acid with 72.3 % of purity. The process consists of five steps: 1- Enzymatic and chemical esterification of the tall oil fatty acids with methanol to convert the TOFA in methyl esters; 2- Stripping of water/methanol; 3- Esterification of the free sterols with boric acid. 4- Separation of the methyl esters and rosinic acids from the sterol borates by distillation and 5- Separation of the methyl esters from the rosinic acids by distillation. The process was patented by Cognis Brasil. / Doutorado / Quimica Organica / Doutor em Ciências

’Kentucky 31’ endophyte-free tall fescue fertilized with 160 kg N ha⁻¹yr⁻¹ was compared to similar fescue grown with ’Cimarron’ alfalfa in a randomized block pasture experiment with four replications. Quality and yield of stockpiled forages and performance and serum minerals of grazing steers were investigated during 1991-92 and 1992-93. Effects of grazing and timing of initiation of stockpiling forages were investigated during autumn of 1992. Rate and extent of release of Ca, Mg, P, S, Cu, and Fe from stockpiled forages were determined in a dacron bag study in 1992-93. In 1991-92, stockpiled N-fertilized fescue improved steer performance over stockpiled fescue-alfalfa (P<0.05); in 1992-93, this result was reversed (P<0.05) due to forage availability. Blood urea nitrogen was higher (P<0.07) and serum Ca and S were higher (P<0.05) in steers which grazed stockpiled fescue-alfalfa. September stockpiling of fescue-alfalfa improved botanical composition, yield, and forage quality, compared to August stockpiling. September stockpiling of N-fertilized fescue improved quality but lowered yield, compared to August stockpiling. Fescue-alfalfa had higher (P<0.05) yield and improved botanical composition when grazing occurred. Nitrogen- fertilized fescue had higher (P<0.05) yield when mechanically harvested. Alfalfa released P, Ca, Mg, S, and Fe to a greater extent and rate than either type of fescue at 24 h and P, Mg, S, and Fe at 72 h (P<0.05). Fescue grown with alfalfa released S to a greater extent and rate than N-fertilized fescue, Fescue-alfalfa produces animal performance as good or better than N-fertilized tall fescue, while eliminating need for N-fertilization. / Master of Science