Conselho Nacional de Desenvolvimento Científico e Tecnológico / The experiment was conducted to evaluate the growth and reproductive development of beef heifers from 10 to 14 months of age in three food systems. Ryegrass pasture exclusively (Lolium multiflorum Lam.) or on pasture and receiving rice bran (0.8% of body weight) with or without ionophore. The experimental design was a completely randomized design with repeated measures, three food systems and nine replications, each animal considered an experimental unit. Body weight gain, body condition score and weight:height ratio (kg:cm) of heifers that received more ionophore rice bran were higher than those observed for heifers exclusively on ryegrass or receiving rice bran without ionophore. Regardless of the food system had hip height and pelvic area similar. Heifers that received rice bran with or without ionophore had higher reproductive tract score (RTS) that heifers exclusively on ryegrass. Heifers that received rice bran as a supplement with or without ionophore, the initial body weight of heifers was that best explained the variation in RTS, while the average daily gain of heifers on ryegrass exclusively explained the variation in RTS. / O experimento foi conduzido com o objetivo de avaliar o crescimento e o desenvolvimento reprodutivo de bezerras de corte dos 10 aos 14 meses em três sistemas alimentares, exclusivamente em pastagem de azevém (Lolium multiflorum Lam.) ou em pastagem e recebendo farelo de arroz integral (FAI) com ou sem adição de ionóforo. A quantidade diária de FAI correspondeu a 0,8% do peso corporal. O delineamento experimental foi o inteiramente casualizado, com medidas repetidas no tempo, três sistemas alimentares e nove repetições, sendo cada animal considerado uma unidade experimental. O peso corporal, ganho de escore de condição corporal e de relação peso:altura (kg:cm) de bezerras que receberam FAI mais ionóforo foram superiores aos observados por bezerras exclusivamente em azevém ou recebendo FAI sem adição de ionóforo. Independente do sistema alimentar as bezerras apresentaram altura de garupa e área pélvica similar. Bezerras que receberam FAI com ou sem ionóforo apresentaram maior escore de trato reprodutivo (ETR) que bezerras exclusivamente em azevém. Para bezerras que receberam FAI como suplemento com ou sem adição de ionóforo, o peso corporal inicial foi que melhor explicou a variação em ETR, enquanto o ganho médio diário das bezerras exclusivamente em azevém explicou a variação em ETR.

Orientador: Ricardo Andrade Reis / Banca: Telma Teresinha Berchielli / Banca: Ana Claudia Ruggieri / Banca: Flávio Augusto Portela Santos / Banca: Valdo Rodrigues Herling / Resumo: O objetivo deste estudo foi avaliar os efeitos da suplementação protéica e do uso de monensina e/ou Saccharomyces cerevisiae, nos parâmetros da fermentação ruminal (pH, NH3 e ácidos acético, propiônico e butírico), no consumo de forragem e desempenho de novilhas de corte recriadas em pastagem de capim-Marandú, em duas épocas do ano (transição águas/secas e secas). Os tratamentos avaliados foram: sal mineral (SM); suplemento protéico (SP); suplemento protéico com monensina (SPM); suplemento protéico com levedura (SPL); e suplemento protéico com monensina e levedura (SPML). De acordo com a fermentação ruminal, observou-se alterações no teor do ácido propiônico e razão C2:C3, em resposta ao tratamento SPM. Nas águas, observou-se a influência do pasto no padrão de fermentação ruminal, pois a concentração total de AGCC (133,1mM), ácido acético (101, 4 mM), ácido propiônico (21,1 mM) e ácido butírico (10,7 mM) foram superiores aos demais tratamentos às 6 h. Nas secas, a suplementação mineral protéica melhorou os atributos de fermentação ruminal, porém não houve diferenças estatísticas entre os tratamentos e, a inclusão de levedura à dieta (SPL) aumentou as concentrações de AGCCtotal (109,2mM), acético (80,7mM), propiônico (19,1mm) e butírico (9,4 mM), em relação à inclusão de monensina (67,0, 50,4, 11,8 e 4,8 mM, respectivamente). Quanto ao teor de NH3, na transição águas/secas e secas, respectivamente, às 3h após a refeição foi de 6,7 e 4,8 mg/dL nos animais que consumiam...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: To evaluate the protein supplementation associated with monensin and/or Saccharomyces cerevisiae effects on the ruminal parameters (pH, NH3, acetic, propionic and butiric acids), dry matter intake, and heifers performance grazing Marandu grass pasture in different times (the end of rainy and dry season) this trial was conducted. The evaluated treatments were: mineral salt (MS), protein supplement (PS), PS plus monensin (PSM), PS plus S. cerevisiae (PSL), PS plus monensin and S. cerevisiae (PSML). The PSM changed the ruminal propionic acid values and the C2:C3 ratio. In the end of rainy season, the forage characteristics affected the ruminal parameters. Total fatty acid (133.1 mM), acetic (101.4 mM), propionic (21.1 mM), and butiric acid (10.7 mM) values were greatest on the PSM animals evaluated at six hours after the supplementation. In the dry season, the protein supplementation in general changed the ruminal parameters. In the end of the rainy season and dry season, the MS animals presented NH3 level, respectively of the 6.7 and 4.8 mg/dL, three hours after supplementation. However, the supplemented animals, in average showed 22.3, and 27.6 mg/dL of the ruminal NH3. Low herbage mass was observed on August (2.8 t/ha), and September (1.9 t/ha). The weights gains were 0.4, and 0.2 kg/d on the SP, and 0.2, and -0.06 kg/d on the SM animals, on August and September, respectively. On the end of the rainy season the PSM animal showed 9.8 kg more gain than the PSML. During the end of rainy season the SM heifers presented highest forage intake (2.16% BW), and monensin addition reduced forage intake in 18%. In the dry season the MS heifers presented 2.08% BW of forage, compared to the supplemented animals (1.55% BW)...(Complete abstract click electronic access below) / Doutor

This work was focused on the preparation of model stabilized phospholipid membranes formed on porous polycarbonate carrier. 1,2-dipalmitoyl-sn-glycero-3-phosphocholin was used for their formation in hydrophilic pores of polycarbonate carrier. For characterization of the formation of phospholipid layers, their changes and a study of transport processes, electrochemical impedance spectroscopy and voltammetry were used. Transport of cadmium and copper ions was studied in the presence and in the absence of ionophore calcimycin which was incorporated into the formed of phospholipid membrane. Because these ions are often bound in complexes with various substances, such as low molecular weight organic acids (LMWOAs), this work was also focused on the transport of copper and cadmium ions across the model phospholipid membranes in the presence of malic acid, citric acid and oxalic acid at different pH. Besides the use of ionophore, some pilot experiments were performed to realize the transfer of copper ions using two peptides, nisin and transportan 10. Formation of phospholipid membranes and the transport processes were characterized by two proposed electric equivalent circuits which correspond to the covered and to the uncovered polycarbobate carrier. Keywords: Phospholipids, Membranes, Ionophore, Peptid....

Veterinary pharmaceuticals are routinely used in livestock production to treat diseases, prevent infections, and promote growth. However, the potential release of pharmaceuticals from agricultural activities has raised concerns because they may pose detrimental effects to the ecosystems and human health, for example fostering the evolution of antibiotic-resistant bacteria in the natural environment. A better understanding of the environmental fate of veterinary pharmaceuticals is critical to properly assess and mitigate their risks. This dissertation focuses on a major group of veterinary pharmaceuticals, ionophore antibiotics (IPAs), which is sold at over 4 million kilograms per year and constitutes more than one third of the total antibiotic consumption by the livestock industry in the U.S. Despite the extensive usage of IPAs, their environmental fate was not well-understood. Therefore, this study aimed at achieving a comprehensive understanding of the occurrence, persistence, and transformation of IPAs from poultry litter before and after applications to the agricultural lands. Three of the most commonly used members of IPAs were investigated in this study: monensin (MON), salinomycin (SAL), and narasin (NAR). Based on the common management practices of poultry litter, the potential abiotic and biotic transformation reactions of IPAs were examined under varying conditions relevant to the water-soil-litter systems. This dissertation consists of three sections. First, a robust analytical method was developed to quantify IPAs in various environmental compartments, especially in high organic-containing matrices such as poultry litter, and soil and runoff from litter-fertilized lands. Efforts were made to optimize the analytical method with respect to improving extraction recovery, reducing matrix effects, and validating a surrogate standard. Second, lab-scale experiments were set up to determine the chemical properties of IPAs in aqueous environments and to study the abiotic transformation of IPAs, including hydrolysis and photolysis. The results showed that IPAs are prone to hydrolytic transformation in acidic environments, which are likely to be encountered in acidic soils, alum-amended litter (alum: Al₂(SO₄)₃•12H₂O), and acidic runoff. Multiple transformation pathways were proposed based on the identified hydrolysis products. It is also noteworthy that the hydrolysis products of MON still exhibited a toxic effect on the selected microorganism (Bacillus subtilis). SAL and NAR were found to undergo direct photolysis under both UV light and sunlight irradiation. In natural water matrix, IPAs were also degraded by indirect photolysis with hydroxyl radicals generated by light-excited nitrate. Dissolved organic matter can shield IPAs from light and slow down their photolysis. Third, the biodegradation potential of IPAs was first tested in litter and soil microcosms. Factor analysis was conducted to delineate the interaction of water and temperature on IPA degradation in the litter. Litter-fertilized and non-fertilized soil microcosms were compared on the degradation of MON and SAL. Furthermore, the inhibition and biotransformation potential of IPAs were assessed under different redox conditions with litter-enriched cultures. Inhibition tests focused on examining IPAs’ impact on microbial community functions, including denitrification, sulfate-reduction, and methane production. Biodegradation tests were conducted with different electron acceptors, including oxygen, nitrate, sulfate, and organic carbons, with efforts to elucidate primary biotransformation products. On the basis of the results obtained in this study, several recommendations on litter management and IPA selection were made to help mitigate the release and transport of IPAs, as well as enhance their degradation. Overall, this study significantly improved the understanding of the environmental fate of IPAs and the obtained knowledge can aid proper selection of IPAs and management strategies in future applications to minimize the risks of antibiotic micropollutants in the environment.

Made available in DSpace on 2014-06-11T19:33:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-02-12Bitstream added on 2014-06-13T20:25:12Z : No. of bitstreams: 1 bertipaglia_lma_dr_jabo.pdf: 804905 bytes, checksum: 0d0438eeb116ed2ed0780bcd278b3b2c (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Bellman Nutricao Animal Ltda / Brascan - Fazenda Bartira / Saf do Brasil - DiviSão Agropecuaria / O objetivo deste estudo foi avaliar os efeitos da suplementação protéica e do uso de monensina e/ou Saccharomyces cerevisiae, nos parâmetros da fermentação ruminal (pH, NH3 e ácidos acético, propiônico e butírico), no consumo de forragem e desempenho de novilhas de corte recriadas em pastagem de capim-Marandú, em duas épocas do ano (transição águas/secas e secas). Os tratamentos avaliados foram: sal mineral (SM); suplemento protéico (SP); suplemento protéico com monensina (SPM); suplemento protéico com levedura (SPL); e suplemento protéico com monensina e levedura (SPML). De acordo com a fermentação ruminal, observou-se alterações no teor do ácido propiônico e razão C2:C3, em resposta ao tratamento SPM. Nas águas, observou-se a influência do pasto no padrão de fermentação ruminal, pois a concentração total de AGCC (133,1mM), ácido acético (101, 4 mM), ácido propiônico (21,1 mM) e ácido butírico (10,7 mM) foram superiores aos demais tratamentos às 6 h. Nas secas, a suplementação mineral protéica melhorou os atributos de fermentação ruminal, porém não houve diferenças estatísticas entre os tratamentos e, a inclusão de levedura à dieta (SPL) aumentou as concentrações de AGCCtotal (109,2mM), acético (80,7mM), propiônico (19,1mm) e butírico (9,4 mM), em relação à inclusão de monensina (67,0, 50,4, 11,8 e 4,8 mM, respectivamente). Quanto ao teor de NH3, na transição águas/secas e secas, respectivamente, às 3h após a refeição foi de 6,7 e 4,8 mg/dL nos animais que consumiam... / To evaluate the protein supplementation associated with monensin and/or Saccharomyces cerevisiae effects on the ruminal parameters (pH, NH3, acetic, propionic and butiric acids), dry matter intake, and heifers performance grazing Marandu grass pasture in different times (the end of rainy and dry season) this trial was conducted. The evaluated treatments were: mineral salt (MS), protein supplement (PS), PS plus monensin (PSM), PS plus S. cerevisiae (PSL), PS plus monensin and S. cerevisiae (PSML). The PSM changed the ruminal propionic acid values and the C2:C3 ratio. In the end of rainy season, the forage characteristics affected the ruminal parameters. Total fatty acid (133.1 mM), acetic (101.4 mM), propionic (21.1 mM), and butiric acid (10.7 mM) values were greatest on the PSM animals evaluated at six hours after the supplementation. In the dry season, the protein supplementation in general changed the ruminal parameters. In the end of the rainy season and dry season, the MS animals presented NH3 level, respectively of the 6.7 and 4.8 mg/dL, three hours after supplementation. However, the supplemented animals, in average showed 22.3, and 27.6 mg/dL of the ruminal NH3. Low herbage mass was observed on August (2.8 t/ha), and September (1.9 t/ha). The weights gains were 0.4, and 0.2 kg/d on the SP, and 0.2, and -0.06 kg/d on the SM animals, on August and September, respectively. On the end of the rainy season the PSM animal showed 9.8 kg more gain than the PSML. During the end of rainy season the SM heifers presented highest forage intake (2.16% BW), and monensin addition reduced forage intake in 18%. In the dry season the MS heifers presented 2.08% BW of forage, compared to the supplemented animals (1.55% BW)...(Complete abstract click electronic access below)

[ES] El calcio (Ca2+) es un catión esencial que juega un papel fundamental en todos los organismos vivos. Desde el punto de vista funcional, el Ca2+ actúa como un segundo mensajero que regula distintos procesos celulares. Trabajos anteriores indican que la señalización mediante Ca2+ podría estar implicada en las primeras etapas de la inducción de la embriogénesis in vitro de las plantas, pero el verdadero papel del Ca2+ en este proceso es aún desconocido. Por eso, el principal objetivo de la presente Tesis es el estudio del papel del Ca2+ en la embriogénesis in vitro mediante dos sistemas in vitro: la embriogénesis somática y la embriogénesis de microsporas. Para determinar la importancia de la homeostasis del Ca2+ en la inducción de la embriogénesis y las dinámicas de los niveles de Ca2+ durante la inducción y el establecimiento de embriones somáticos y derivados de microsporas, se utilizaron tratamientos químicos y se detectaron los niveles de Ca2+ mediante sondas fluorescentes y sensores cameleon codificados genéticamente, visualizados con microscopía fluorescente y confocal. Observamos que el aumento de Ca2+ es un marcador temprano en la inducción de la embriogénesis in vitro y que los niveles de Ca2+ durante la embriogénesis in vitro son dinámicos en todos los sistemas estudiados. Además, las oscilaciones en los niveles de Ca2+ podrían estar relacionadas con los procesos de diferenciación que ocurren en las células inducidas una vez une el Ca2+ a la calmodulina. Mostramos que un aumento de Ca2+ dentro de un rango definido de concentración tiene un efecto positivo, dependiendo del sistema, en la producción de embriones, siendo más sensibles aquellos sistemas basados en suspensiones de células aisladas que aquellos que usan tejidos como explantes. Finalmente, estudiamos el papel de la calosa durante la embriogénesis somática, observando que la inhibición de la deposición de calosa impide el desarrollo embrionario, lo que sugiere una relación entre la formación de una barrera de calosa y el establecimiento de la identidad embrionaria en las células somáticas. / [CAT] El calci (Ca2+) és un catió essencial que juga un paper fonamental en tots els organismes vius. Des del punt de vista funcional, el Ca2+ actua com a un segon missatger que regula diferents processos cel·lulars. Treballs anteriors indiquen que la senyalització mitjançant el Ca2+ podria estar implicada en les primeres etapes de la inducció de l'embriogènesi in vitro de les plantes, però el paper real del Ca2+ en aquest procés encara és desconegut. Per això, el principal objectiu de la present Tesi és l'estudi del paper del Ca2+ en l'embriogènesi in vitro mitjançant dos sistemes in vitro: l'embriogènesi somàtica i l'embriogènesi de micròspores. Per tal de determinar la importància de l'homeòstasi del Ca2+ en la inducció de l'embriogènesi i les dinàmiques dels nivells de Ca2+ durant la inducció i l'establiment d'embrions somàtics i derivats de micròspores, es van utilitzar tractaments químics i es van detectar els nivells de Ca2+ mitjançant sondes fluorescents i sensors de cameleon codificats genèticament, visualitzats amb microscòpia fluorescent i confocal. Vam observar que l'augment de Ca2+ és un marcador primerenc en la inducció de l'embriogènesi in vitro i que els nivells de Ca2+ durant l'embriogènesi in vitro són dinàmics en tots els sistemes estudiats. A més, les oscil·lacions en els nivells de Ca2+ podrien estar relacionades amb els processos de diferenciació que tenen lloc en les cèl·lules induïdes una vegada uneix el Ca2+ a la calmodulina. Vam mostrar que un augment de Ca2+ dins d'un rang definit de concentració té un efecte positiu, depenent del sistema, en la producció d'embrions, essent més sensibles aquells sistemes basats en suspensions de cèl·lules aïllades que aquells que usen teixits com a explants. Finalment, vam estudiar el paper de la cal·losa durant l'embriogènesi somàtica, i vam observar que la inhibició de la deposició de cal·losa impedeix el desenvolupament embrionari, la qual cosa suggereix una relació entre la formació d'una barrera de cal·losa i l'establiment de la identitat embrionària en les cèl·lules somàtiques. / [EN] Calcium (Ca2+) is an essential cation that plays fundamental roles in all living organisms. From a functional point of view, Ca2+ acts as a second messenger that regulates different cellular processes. Previous works point to the fact that Ca2+ signaling may be involved in the early stages of induction of in vitro plant embryogenesis, but the actual role of Ca2+ in this process remained unveiled. Thus, the main goal of the present Thesis is to study the role of Ca2+ in in vitro embryogenesis using two in vitro systems: somatic embryogenesis and microspore embryogenesis. Chemical treatments and detection of Ca2+ with fluorescent probes and genetically-encoded cameleon sensors imaged by fluorescence and confocal microscopy were performed to determine the importance of Ca2+ homeostasis for induction of embryogenesis and the dynamics of Ca2+ levels during the induction and establishment of somatic and microspore-derived embryos. We observed that Ca2+ increase is an early marker of induction of in vitro embryogenesis and Ca2+ levels during in vitro embryogenesis are dynamic in all the systems we studied. Moreover, Ca2+ oscillations might be related to the differentiation processes that take place in the induced cells upon binding to calmodulin. We showed that Ca2+ increase within a defined range has system-specific positive effects in embryo yield, being more sensitive those systems using isolated cell suspensions rather than those using tissues as explants. Finally, we studied the role of callose during somatic embryogenesis, and we observed that inhibiting callose deposition prevents embryo development, which suggests a relationship between the formation of a callose barrier and the establishment of embryo identity in somatic cells. / Calabuig Serna, A. (2023). Multidisciplinary study of the role of calcium in plant in vitro embryogenesis [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/196022