Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2004. / Härtill 6 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2004. / Härtill 4 uppsatser.

Un défi de la modélisation des cultures est de comprendre et de reproduire les hétérogénéités de développement de la végétation à l'échelle du pédon afin de prédire le rendement. Le but de ce travail est de proposer une méthode de spatialisation des modèles de culture par la spatialisation des données d'entrée, notamment de la réserve utile, pour reproduire les hétérogénéités observées au sein d'un petit sous-bassin versant. Ce travail a été mené en 3 étapes : (1) calage du modèle STICS au contexte local (2) spatialisation des entrées du modèle par une méthode dérivée desapproches SCORPAN et (3) évaluation des simulations spatialisées avec STICS. Préalablement à la spatialisation des données d'entrée du modèle STICS, il était nécessaire d'identifier quels étaient les déterminants des hétérogénéités de végétation observéesau sein du sous-bassin versant expérimental étudié. Pour cela un travail préliminaire a conduit à délimiter les situations pouvant être reproduites par le modèle et les variables pouvant être spatialisées ainsi que de définir une stratégie optimale pour spatialiser les entrées. Sur cette base, une méthodologie de travail a pu être définie pour évaluer et paramétrer le modèle sans spatialisation (approche locale) dans un contexte de sols ayant des propriétés vertiques. Cette particularité des sols locaux nécessite d'établir un nouveau domaine de validité du modèle, compte tenu des hypothèses indispensables (processus considérés comme négligeables) pour simuler dans ce contexte. Par ailleurs, le protocole utilisé pour déterminer la réserve utile a nécessité d'établir la manière dont l'incertitude de la mesure se propageait dans le modèle. Ainsi, grâce à ce travail de spatialisation statistique des mesures, le modèle STICS a pu être utilisé sur des mailles de 8 x 8 m pour simuler le développement de végétation sur tout le sous-bassin versant étudié. / One of the challenges in crop modelling is to understand and be able to reproduce heterogeneities in crop development at intra-plot scale in order to better predict the yield. The aim of this work was to suggest a method for spatializing the input data of crop models, in particular the water stock accessible to plants, in order to reproduce the differences in crop development within a subwatershed. This work was carried out in 3 main steps: (1) adaptationof the STICS crop model to the local context, (2) spatialization of the inputs by the spatial correlation method (SCORPAN-like method) and (3) evaluation of the simulated spatialization with STICS model. Prior to spatialization step, it was necessary to identify the determinants of vegetation heterogeneities observed within the experimental subwatershed. A preliminary study led to delimit the situations that could be reproduced by the model and to identify variables that could be spatialized as well as to define an optimal strategy to spatialize the inputs. Based on this, a methodological work was established to evaluate and parameterize the model without spatialization (local approach) in a context of soils with vertisolic properties. Particularity of local soils properties underlined the need to define a new domain of model validity. Moreover, the protocol used to measure water holding capacity, implied a needful and important step that was to determine the propagation of measurement uncertainty in the model. Finally, thanks to statistical spatialization of measurements, STICS model was used on 8 x 8 m meshes to simulate vegetation development on the whole studied subwatershed.

No description available.

Master of Science / Food Science Institute, Animal Science and Industry / Karen A. Schmidt / Yogurt is a good source of whey proteins, which have been reported to provide positive health benefits. During yogurt manufacture, the yogurt mix receives a heat treatment which pasteurizes the product, denatures the whey proteins affecting their availability, and enhances quality attributes. Thus the objective of this research was to improve the undenatured whey protein content in yogurt. The study was divided in two parts. The first part focused on the effect of pasteurization treatments of yogurt mixes (65 °C for 30 min vs. 90 °C for 10 min) on the yogurt firmness, G’, L*, syneresis and water holding capacity (WHC), and how these properties change as a function of storage. Nonfat dry milk (NFDM) was reconstituted (~11% w/v) pasteurized, cooled, inoculated with yogurt culture, incubated to pH 4.5, stored at 5 °C ±1 and evaluated for various physical and chemical properties on days 1, 15 and 29. The experiment was replicated 3 times and data were analyzed by SAS®. Yogurt samples had a 5-fold difference in whey protein denaturation (WPD) and the greater the WPD the greater the firmness, G’, L* and WHC but lesser the syneresis. During yogurt storage, L*, G’, syneresis and WHC increased. The second part of this research focused on whey protein concentrate (WPC) addition (3%) in yogurt mix combined with two pasteurization treatments (70 °C for 30 min vs. 90 °C for 10 min) to determine their effects on the yogurt quality. Yogurt mixes were formulated using 12.5% NFDM or 9.5% NFDM and 3% WPC and a procedure similar to the previous study was followed. The WPC addition resulted in a yogurt with decreased firmness, G’, WHC but increased syneresis. Yogurt made from mixes pasteurized at 90 °C for 10 min had ~60% WPD and comparable quality attributes regardless of WPC addition. Thus, additional WPC and less WPD in this study resulted in a yogurt with slightly lesser quality attributes but more undenatured whey proteins in the final yogurt.

A moderna suinocultura vem nos últimos anos avançando no desenvolvimento e no emprego de tecnologias que visam o aumento da performance produtiva e econômica do segmento. As inovações associadas aos métodos de castração e modificadores metabólicos têm sido avaliadas, em particular o uso da imunocastração e dos repartidores de energia (ractopamina). Embora os ganhos zootécnicos e industriais destas tecnologias já estejam bem discutidos, o real impacto do emprego juntas ou isoladas sobre a qualidade tecnológica da carne pelo seu efeito na matriz bioquímica, necessita de estudos mais aprofundados. Desta forma, esta pesquisa científica foi direcionada para avaliar os efeitos, focando nas alterações dos perfis eletroforéticos da carne, advinda de animais produzidos comercialmente, utilizando concomitantemente ractopamina e imunocastração. Foram utilizados 48 suínos, criados comercialmente, sendo 8 suínos por tratamento (machos castrados cirurgicamente - CC, machos imunocastrados - IM, e fêmeas - F) recebendo dietas suplementadas com (CR) ou sem (SR) ractopamina na fase final da terminação. Avaliaram-se as características qualitativas da carne, tais como o pH, a cor objetiva, a capacidade de retenção de água (perda de água por gotejamento - drip loss, perda por cocção - PCOC, e perda por descongelamento - PDESC), maciez objetiva (força de cisalhamento) e perfil eletroforético. A utilização conjunta da imunocastração com a ractopamina influenciou o pH 24 horas do lombo suíno, a luminosidade (L*) e a força de cisalhamento, sendo que o pH e a força de cisalhamento foram maiores e a luminosidade menor em IC-CR na dieta. Porém, essa influência não foi verificada na análise eletroforética unidimensional. O perfil proteico foi significativamente influenciado pelo fornecimento do β-agonista adrenérgico. Diferenças na abundância de peptídeos foram verificadas para as variáveis qualitativas da carne maciez, capacidade de retenção de água (drip loss e descongelamento) e luminosidade. Aumento nos volumes normalizados dos peptídeos reduziu a PDESC e melhorou a maciez objetiva, enquanto que o drip loss aumentou quando não houve a suplementação com ractopamina na dieta. Os resultados demonstraram que somente o β-agonista adrenérgico foi o responsável pelas diferenças verificadas no perfil proteico. O efeito simultâneo imunocastração com a inclusão da ractopamina na dieta não propociou impactos na qualidade tecnológica da carne. / The modern swine industry has in recent years to advance the development and use of technologies aimed at increasing production and economic performance of the segment. Innovations associated methods of castration and metabolic modifiers have been evaluated, in special the use of immunocastration and feed additive (ractopamine). Although the production growth and industrial gains of these technologies are already well discussed, the real impact of employment together or isolated on the technological quality of meat by its effect on the biochemical matrix, requires further study. Therefore, this scientific research was directed to evaluate the effects, concentrating on changes in electrophoretic profiles of meat, resulting animals commercially produced concurrently using ractopamine and immunocastration. 48 animals were used commercially created, 8 per treatment (castrates - CC, immunocastrated - IM, and female - F) fed diets supplemented with (CR) or without (SR) ractopamine at the final stage of finishing. We evaluated the qualitative characteristics of meat, such as pH, color, water-holding capacity (drip loss, cooking loss - PCOC, and loss defrosting - PDESC) objective tenderness (shear force) and electrophoretic profile. The combined use of immunocastration with ractopamine influence pH 24h swine loin, the lightness (L*) and shear force, and pH, and shear force were higher and lower luminosity in IC-CR in the diet. However, this effect wasn\'t seen in the one-dimensional electrophoretic analysis. The protein profile was significantly influenced by the supply of β-adrenergic agonist. Differences in the abundance of peptides were checked for qualitative variables of meat tenderness, water retention capacity (drip loss and defrosting) and luminosity. The increase in the volume of standard peptides pDesc reduced and improved objective tenderness, while the drip loss increased when no supplementation with dietary ractopamine. The results demonstrate that only the β-adrenergic agonist was responsible for the observed differences in the protein profile. The effect simultaneously immunocastration with the addition of ractopamine in the diet not influence impacts on technological meat quality.

Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2016-08-02T17:10:18Z No. of bitstreams: 1 2004 - Silvio Jos? Elia Galv?o.pdf: 2579671 bytes, checksum: ac93bbefdc6fd8aa6f67c30746be92d5 (MD5) / Made available in DSpace on 2016-08-02T17:10:18Z (GMT). No. of bitstreams: 1 2004 - Silvio Jos? Elia Galv?o.pdf: 2579671 bytes, checksum: ac93bbefdc6fd8aa6f67c30746be92d5 (MD5) Previous issue date: 2004-02-27 / Empresa Brasileira de Pesquisa Agropecu?ria - EMBRAPA; Empresa de Pesquisa Agropecu?ria do Estado do Rio de Janeiro - Pesagro. / The aim of this study was to identify the main properties of the green coconut shell fiber and conduct experiments with it. The fiber received different treatments in order to make it possible to give technical orientation for its use as substrate for lettuce seedlings growth. The green coconuts used in the experiments came from the selective collection of garbage produced by the consumption of green coconuts in natura at the beaches and other places where they are sold, as well as residues from agro-industries that bottle green coconut water. The green coconuts had their water consumed and were collected without any preservation or transportation criteria in order to repeat the habitual treatment given to solid residue of that sort in large urban centers. All the fruits used were kept in the shade at room temperature, for the maximum period of four (4) days after the consumption of the water. They were manually chopped and ground, while still green, in grass crushers. Eight (08) treatments were defined in order to carry out the study to be done with the green coconut fiber, as follows: treatment T1 - crushed green coconut fiber; treatment T2 - ground green coconut fiber; treatment T3 - crushed and ground green coconut fiber; treatment T4 - crushed and ground green coconut fiber + bovine manure; treatment T5 ? crushed green coconut fiber + bovine manure; treatment T6 - ground green coconut fiber + bovine manure; treatment T7 ? crushed green coconut fiber + limestone; treatment T8 ? crushed and washed green coconut fiber. In order to compare the different treatments, three commercial substrates were chosen to be used in the study, namely: substrate Plantmax HA, from Eucatex Agro, as treatment T9; substrate MP Horta 2, from Mecplant, as treatment T10; substrate MP FLORESTAL, from Mecplant, as treatment T11. Several chemical and physical analyses of the treatments were made in order to make decisions about the manipulation of treatments, looking for final results in lettuce seedlings production similar to those obtained with commercial substrates. All the green coconut shell fiber treatments presented physical characteristics which made it easy to manipulate them in its use as substrate in plant propagation, as well as high water-holding capacity, high carbon / nitrogen ratio, electric conductivity, and porosity. When the fiber was added to manure, the result was good for treatment T5. The electrical conductivity (EC) was reduced when the coconut shell fiber was washed with water. / O objetivo do presente trabalho foi identificar as principais caracter?sticas da fibra do coco verde e experimentar tratamentos com esta fibra de modo a possibilitar orienta??o t?cnica para sua utiliza??o como substrato para plantas em cultivo de alface. Foram utilizados frutos de coco verde oriundos da coleta seletiva de lixo produzido pelo consumo in natura de frutos na orla das praias e outros pontos de vendas, assim como de res?duos de agroind?strias envasadoras de ?gua de coco-verde. Os frutos de coco verde tiveram sua ?gua consumida, sendo coletados sem quaisquer crit?rios de preserva??o e transporte, de modo a repetirem uma situa??o habitual de trato dado a res?duos s?lidos desta natureza em grandes centros urbanos. Todos os frutos utilizados foram mantidos ? sombra, em temperatura ambiente, por no m?ximo quatro (04) dias ap?s terem sua ?gua consumida, sendo picados com ferramentas de corte manual e triturados em picadeiras de capim de uso em agropecu?ria ainda verde. Foram definidos oito (08) tratamentos com fibra de coco verde para a condu??o dos trabalhos com a fibra de coco, a saber: tratamento T1 - fibra de coco picada; tratamento T2 - fibra de coco mo?da; tratamento T3 - fibra de coco picada + mo?da; tratamento T4 - fibra de coco picada + mo?da + esterco bovino; tratamento T5 - fibra de coco picada + esterco bovino; tratamento T6 - fibra de coco mo?da + esterco bovino; tratamento T7 - fibra de coco picada + calc?rio; tratamento T8 - fibra de coco picada lavada. Comparativamente, foram escolhidos para uso nos estudos 03 (tr?s) substratos comerciais para plantas: substrato Plantmax HA, da empresa Eucatex Agro, como tratamento T9; substrato MP Horta 2, da empresa Mecplant, como tratamento T10; e substrato MP Florestal, da empresa Mecplant, como tratamento T11. In?meras an?lises qu?micas e f?sicas foram realizadas com os tratamentos de modo a permitirem tomadas de decis?es sobre o manejo dos mesmos, buscando resultados finais na produ??o de mudas de alface semelhantes aos obtidos com substratos comerciais. Todos os tratamentos ? base de fibra de coco apresentaram caracter?stica f?sica de f?cil manejo para seu uso como substrato para plantas, al?m de elevada capacidade de reten??o de ?gua, rela??o carbono/nitrog?nio, condutividade el?trica e porosidade. A adi??o de esterco bovino promoveu resultado positivo no tratamento T5. A lavagem da fibra com ?gua reduziu a condutividade el?trica (CE) da casca do coco-an?o verde.

Irrigated agriculture is the primary consumer of limited worldwide freshwater resources. Drought, growing world populations, and environmental demands compete with irrigation for freshwater resources"”threatening sustainable global food, fuel, and fiber production. This escalating global crisis demands that agriculture produce more food using less water. Traditional irrigation management has used technology to apply uniform irrigation rates across landscapes"”ignoring natural environmental variation. This provides inherent inefficiencies of over- or under- irrigation within individual fields. Variable-rate irrigation (VRI) is modern technology that employs global positioning systems and geographic information systems to match irrigation to spatially variable crop water demands within a field. Although commercially available, VRI lacks scientifically validated decision support systems to determine spatially and temporally variable crop water demand. The purpose of this research is to explore spatial and temporal variations in crop water demand to inform growers utilizing VRI. This research consists of four seasons of winter wheat (Triticum aestivum L.) production on a commercial farm in Idaho that employs a VRI system. In Chapter 1, the spatial variation of crop water productivity (CWP, the grain produced per unit of water consumed), is characterized for two seasons (2016-2017) and we propose a unique conceptual strategy for VRI management targeted at CWP. Observed CWP ranged from 4.1-21 kg ha-1 mm-1 with distinct spatial variation that, when considered together with grain yield, were shown to be useful for VRI management. During the 2017 growing season, VRI zones conserved 25% of irrigation compared to traditional uniform irrigation management. In the second chapter the spatial variation of soil water holding capacity (SWHC) was measured at 90 sampling points throughout the field. Then, during the 2016-2017 growing seasons, the spatial and temporal variation of soil moisture were modelled to characterize crop stress and its influence on grain yield. Soil within the field showed large spatial variation of SWHC, ranging from 147-369 mm. Under uniform irrigation in 2016, the natural variation of TAW created 21 day variation in the onset of crop stress throughout the field and under VRI in 2017 the onset of crop stress spanned 56 d. Surprisingly the variations in TAW did not statistically influence yield in 2016, and in 2017 the rate of irrigation predicted yield and TAW again did not statistically predict yield. This suggests that other environmental variables should be included when delineating irrigation zones and rates for VRI.

abstract: Aboveground net primary production (ANPP) is an important ecosystem process that, in drylands, is most frequently limited by water availability. Water availability for plants is in part controlled by the water holding capacity of soils. Available water holding capacity (AWHC) of soils is strongly influenced by soil texture and depth. This study drew upon localized rain gauge data and four data-sets of cover-line and biomass data to estimate ANPP and to determine annual precipitation (PPT). I measured soil depth to caliche and texture by layer of 112 plots across the four landscape units for which estimation of ANPP were available. A pedotransfer function was used to estimate AWHC from soil depth increments to depth of caliche measurements and texture analysis. These data were analyzed using simple and multivariate regression to test the effect of annual precipitation and available water holding capacity on aboveground net primary production. Soil texture remained constant among all plots (sandy loam) and depth to caliche varied from 15.16 cm to 189 cm. AWHC and the interaction term (PPT*AWHC) were insignificant (p=0.142, p=0.838) and annual PPT accounted for 18.4% of the variation in ANPP. The y-intercept was significantly different for ANPP ~ annual PPT when considering AWHC values either above or below 3 cm. Shrub ANPP was insensitive to precipitation regardless of AWHC (R2=-0.012, R2=0.014). Results from this study indicate that a model incorporating annual PPT and AWHC may not serve as a good predictor for ANPP at a site level where there is little variation in soil texture. / Dissertation/Thesis / Masters Thesis Sustainability 2019

Industry surveys indicated that up to 16percent of pork is pale, soft, and exudative (PSE); which has reduced functionality. Recently, the cost of sodium phosphates (SP) has escalated. SPs are used to improve water holding capacity (WHC), increase pH, and retard lipid oxidation. Alkaline non-meat ingredient addition could improve PSE pork functionality and replace SP in pork products. The objective was to examine effects of alkaline solutions on pH, color, WHC, and texture of PSE and normal pork gels. Normal (pH 5.6-5.9) and PSE (pH ≤ 5.4) loins were obtained and homogenized. Treatment solutions were: no added solution (control); double-distilled deionized water (ddW); 0.1, 0.2, and 0.3 pecent(w/v) SP; and 0.1, 0.2, and 0.3M potassium bicarbonate (PB), sodium bicarbonate (SB), potassium carbonate (PC), or sodium carbonate (SC). PSE gels had lighter color, lower pH, WHC, and cook yields, and higher TPA values than normal gels. Control and ddW gels had lower pH, and higher L*, a*, and b* values. As treatment levels increased, gels had higher pH, and lower L*, a*, and b* values. SP gels had lower pH, WHC, cook yields, and higher L*, a*, b*, and TPA values compared to PB, SB, PC, and SC gels. PC and SC gels had higher cook yields than normal control gels and PB and SB gels were intermediate. For both meat types, TPA values improved for PB and SB gels compared to normal control gels, but did not differ from SP gels. As levels of PC and SC increased, gels were softer, less cohesive, chewy, and lower in work 2 than other gels. Cooked PSE gels treated with 0.2 or 0.3M PC or SC were less red and yellow and had cook yields that surpassed normal control and ddW gels. Normal and PSE gels treated with 0.2 or 0.3M PC or SC did not differ in TPA measurements for hardness and work. PSE pork functionality was improved with PC or SC addition to be similar to or higher than normal samples. PC and SC are feasible alternatives to replace SP in pork gel systems without loss of WHC, color, or pH.