Submitted by Gabriela Lopes (gmachadolopesufpel@gmail.com) on 2016-09-13T17:43:22Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação.pdf: 594620 bytes, checksum: f2b0642b05c911dff9dba034e3e9d4cd (MD5) / Made available in DSpace on 2016-09-13T17:43:22Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação.pdf: 594620 bytes, checksum: f2b0642b05c911dff9dba034e3e9d4cd (MD5) Previous issue date: 2015-07-07 / Sem bolsa / O objetivo do estudo foi avaliar a produção de forragem, palhada e sementes do azevém anual (Lolium multiflorum Lam.) de ciclo longo (BRS Estações) submetido a diferentes freqüências de desfolha. Foram realizados seis cortes (desfolhas) com quantidade média colhida por corte de 2.039,9kg MS ha-1 com duração do ciclo produtivo de 216 dias ou 2.161,55 GD. O aumento da colheita de forragem foi linear em função do tempo com predomínio de lâminas foliares até o quinto corte. O último corte foi efetuado em final de novembro com uma colheita de 559 kg ha-1 de MS de folhas vivas. A produção total de forragem foi de 15,5 t MS ha- 1 . Máxima colheita de sementes (1.423 kg ha-1) ainda com a execução de três colheitas de forragem (8.178 kg MS ha-1). No entanto, à medida que a execução do corte da forragem avançou no tempo, a partir de 1.000 GD, ocorreu uma queda assintótica no rendimento de sementes. O crescimento das plantas sem a intervenção da desfolha resultou na maior palhada ao final do ciclo da cultura (12,2 t de MS ha-1). Todavia, conforme a utilização da pastagem ao longo do tempo ocorreu uma redução linear da palhada, com valor mínimo, resultante de seis utilizações da pastagem, de 1.688 kg MS ha-1. O máximo número de cortes propicia elevada colheita de forragem com elevada participação de folhas. A execução de três desfolhas não afeta a produção de sementes e possibilita elevada colheita de folhas e a manutenção de significativa palhada ao final do ciclo produtivo da cultura. / The purpose of this study was to evaluate the production of fodder, straw and seeds of a variety annual ryegrass (Lolium multiflorum Lam.) long cycle (BRS Estações) submitted many numbers of defoliation. The variety allowed six cuts (defoliation) with average amount harvested by defoliation 2.039,9kg DM ha-1 with the productive cycle duration of 216 days or 2.161,55 DD. The increase in fodder harvest was linear in relation to time with predominance of leaf blades until the fifth cut. The last cut was made in late November and also made possible the harvest 559 kg of DM ha-1 fresh leaves. The total fodder production was 15,5t DM ha-1. It was possible to obtain the highest seed harvest (1.423 kg ha-1) and by performing three fodder harvest (8.178kg DM ha-1). Nonetheless, as fodder cut running forward in time from, 1.000 DD, there was an asymptotic fall in yield seeds. Plant growth without defoliation intervention resulted in the largest straw at the end of the crop cycle (12,2 t de DM ha-1). However, as the use of grazing over time there was a linear decrease of the straw, with minimum value, resulting from six grazing uses of 1.688 kg DM ha- 1 . The maximum number of cuts provides raised fodder harvest with raised leaves participation. The execution of three defoliation does not affect seed production and enables high leaf harvest and the maintenance of significantly straw at the end of productive cycle of the crop

Les associations symbiotiques entre différentes espèces de champignon du genre Epichloë et des plantes fourragères sont à l’origine de la production de mycotoxines responsables, dans certains pays, de toxicoses du bétail et de pertes économiques. Le développement de d’E. coenophiala dans la fétuque, qui est associé à la production d’ergovaline, est responsable de « fescue foot disease » alors que la présence d’E. festucae var. lolii dans le ray-grass anglais, qui est accompagnée d’une production de lolitrem B, est responsable du « ryegrass staggers » et de la production d’ergovaline, dont les effets toxiques associés à la présence de lolitrème B sont mal documentés. Mon travail de thèse a consisté à explorer les effets de la distribution de différents fourrages de fétuque et ray-grass endophytés toxinogènes produits dans des conditions agricoles françaises, sur la santé et la production animale et les mécanismes d’action de l’ergovaline et du lolitrème B. / The symbiotic associations between different varieties of fungi of the Epichloë kind and forages are responsible for the production of mycotoxins which are responsible of toxicoses in livestock and economic losses in some countries. The development of E. coenophiala in tall fescue, which is associated with the production of ergovaline, is responsible for « fescue foot disease » while the presence of E. festucae var. lolii in ryegrass, which is accompanied by the production of lolitrem B, is responsible for the « ryegrass staggers ». and the production of ergovaline, whose the toxic effects associated in the presence of lolitrem B are poorly documented. My thesis was to explore the effects of the distribution of different toxic forages of endophyte-infected tall fescue or ryegrass produced in French agricultural conditions on health and animal production and the mechanisms of action of ergovaline and lolitrem B.

Les associations symbiotiques Epichloë- graminées fourragères les plus étudiées concernent le ray grass anglais (Lolium perenne) avec Epichloë festucae var. lolii et la fétuque élevée (L. arundinaceum) avec E. coenophiala. Ces champignons peuvent synthétiser des alcaloïdes toxiques pour le bétail tels que l’ergovaline et le lolitrème B. Mon travail de thèse a consisté à explorer les facteurs en lien avec la production de mycotoxines dans les graminées. Pour cela différentes études ont été conduites sur la fétuque et le ray grass afin de révéler i) la présence de souches endophytées toxinogènes dans le Sud Ouest de la France et ii) l’influence des conditions climatiques françaises sur la synthèse d’ergovaline et de lolitrème B dans des variétés fourragères connues pour être responsables de cas de toxicité sur d’autres continents. / The most studied symbiotic associations Epichloë- cool seasons grasses concern perennial ryegrass (Lolium perenne) with Epichloë festucae var. lolii and tall fescue (L. arundinaceum) with E. coenophiala. These fungi can synthesize alkaloids that could be toxic to livestock such as ergovaline and lolitrem B. My thesis work was to explore the factors related to the production of mycotoxins in grasses. Different studies have been conducted on tall fescue and perennial ryegrass to reveal i) the presence of endophyte-infected toxigenic strains in the South West of France and ii) the influence of environmental conditions of Saint-Affrique (Aveyron) on the synthesis of ergovaline and lolitrem B in forage varieties known to be responsible for toxicity on other continents.

Kikuyu (Pennisetum clandestinum) is highly productive during summer and autumn and capable of supporting high cattle stocking rates., The winter and spring production of kikuyu, however, is low, while forage quality, and consequently milk production per cow, is also low compared to temperate grass species. The aim of this study was to determine the dry matter yield, botanical composition, nutritional value, grazing capacity and milk production potential of irrigated kikuyu over-sown with Italian ryegrass (Lolium multiflorum var. italicum), Westerwolds ryegrass (Lolium multiflorum var. westerwoldicum) or perennial ryegrass (Lolium perenne) under an intensive grazing system with Jersey cows. Calibrations for the rising plate meter (RPM) were developed for the kikuyu-ryegrass systems. These calibrations were evaluated for seasonal variation, linearity and were also combined over seasons, treatments and years to develop a calibration equation that could be used by dairy farmers in the region. The three kikuyu based pasture systems reached their peak growth rates during different months and seasons. All treatments experienced lower growth rates during winter, while peak growth rates occurred during spring for the Italian ryegrass treatment; summer for the Westerwolds ryegrass treatment and late spring/early summer for the perennial ryegrass treatment. All three treatments had similar total annual dry matter yields (kg DM ha-1) during the first year of the study. However, during year 2 the PR treatment had a higher annual DM production than IR and WR treatments. The ability of the PR treatment to maintain DM production during periods when the other treatments underwent a dip in production (WR during spring and IR during summer) enabled the PR treatment to maintain a higher annual DM production during year 2 than the systems based on annual ryegrass species. As the kikuyu component increased in kikuyu-ryegrass pastures from winter to summer, the DM and NDF content increased, while the ME content decreased. All three treatments were deficient in Ca throughout the study and deficient in P during summer and autumn for high producing dairy cows. The Ca:P ratio was below the recommended ratio of 1.6:1 for high producing dairy cows throughout the study. The grazing capacity of all three kikuyu-ryegrass systems was lower during winter and autumn than during spring and summer. The seasonal grazing capacity of the perennial ryegrass treatment, however, was more evenly distributed than that of the Italian and Westerwolds ryegrass treatments. The perennial ryegrass treatment had a lower butterfat and milk production per lactation than the Italian and Westerwolds ryegrass treatments during both years, but had the highest milk production per ha. The latter was a result of the higher annual grazing capacity achieved by the perennial ryegrass treatment. It was thus concluded that, because kikuyu over-sown with perennial ryegrass supported a higher number of animals and had a more evenly distributed fodder-flow, it allowed for higher animal production per ha than kikuyu over-sown with annual ryegrass varieties such as Italian and Westerwolds ryegrass. The pre-grazing and post-grazing regressions of all three the kikuyu based pastures developed for the RPM differed over seasons and years, primarily due to the change in botanical composition from ryegrass based pastures during winter to kikuyu-based pastures in the summer and the associated change in pasture structure. The post-grazing regressions developed during the study did not have a lower degree of accuracy (R2 values) than the pre-grazing regressions. The generalised RPM regression equations developed for kikuyu-ryegrass pastures (consisting of large data sets pooled over treatments and years) could be of use to farmers in the surrounding area, but are not recommended for research purposes due to the large errors and variation associated with such regressions. In the event that farmers employ these calibrations it is important that pasture type and pasture management practices be similar to those utilised during the study. The decision on which kikuyu-ryegrass system to utilize should be based on the specific conditions prevalent on a particular farm, an economic analysis on and a comparison between the three systems, as well as the particular fodder-flow program requirements within the pasture system. / Dissertation (MSc(Agric))--University of Pretoria, 2010. / Plant Production and Soil Science / unrestricted

Submitted by Marcos Anselmo (marcos.anselmo@unipampa.edu.br) on 2016-09-23T20:43:47Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) FABIANE QUEVEDO DA ROSA.pdf: 623070 bytes, checksum: d6e7ed987a04d5ad296d7f91b6123a7d (MD5) / Approved for entry into archive by Marcos Anselmo (marcos.anselmo@unipampa.edu.br) on 2016-09-23T20:44:00Z (GMT) No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) FABIANE QUEVEDO DA ROSA.pdf: 623070 bytes, checksum: d6e7ed987a04d5ad296d7f91b6123a7d (MD5) / Made available in DSpace on 2016-09-23T20:44:00Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) FABIANE QUEVEDO DA ROSA.pdf: 623070 bytes, checksum: d6e7ed987a04d5ad296d7f91b6123a7d (MD5) Previous issue date: 2016-08-26 / Com o objetivo de avaliar a proteína bruta fecal como indicador de consumo e digestibilidade de bovinos alimentados com pastagem nativa situada no Bioma Pampa e inclusões de azevém e avaliar a qualidade nutricional dessas pastagens foram realizados dois experimentos em gaiolas de metabolismo. No experimento I, os animais recebiam diferentes níveis de oferta de pastagem nativa onde os tratamentos consistiam em níveis de1,5 e 2,25% do peso vivo de matéria seca e um nível ad libitum, com pelo menos 20% de sobras diárias onde foram realizados seis períodos experimentais, O experimento II consistia em diferentes níveis de inclusão de azevém na dieta de bovinos alimentados com campo nativo, os tratamentos eram 33%, 66% e 100% de azevém em substituição ao campo nativo, em dois períodos experimentias. Os experimentos foram realizados em delineamento inteiramente casualizado com 3 tratamentos e 2 repetições por tratamento em cada período. Os períodos experimentais consistiram de 10 dias de adaptação e 5 dias de coletas, durante o período de coletas foram amostradas as sobras do cocho, a forragem ofertada e ainda a produção total de fezes a cada 24 horas. Realizou-se as medidas de produção fecal, concentração de componentes fecais, consumo de nutrientes e digestibilidade dos componentes da dieta. No capítulo I foram traçadas relações entre digestibilidade e a concentração da proteína bruta fecal (PBf), sendo testados dois modelos não lineares, o exponencial e o hiperbólico gerando as equações de digestibilidade da matéria orgânica(DMO) = 0,709-9,506* exp(-0,041*PBf) com R2 0,61 e DMO = 0,942-38,619/PBf (R2 0,62), respectivamente. A relação de consumo de matéria orgânica (CMO) com a quantidade de PBf, possui comportamento linear, foi então realizada a análise de stepwise para saber quais outras variávies poderiam explicar melhor o modelo junto com a PBf gerando uma equação CMO = -6724,30 + 39*PBf + 2,55*FDNf + 11591,44*DMO com R2 0,95. Determinou-se a relação da proteína bruta (PB) da dieta (g/kg MO) x PBfecal (g/kg MO), PB dieta = 1,346x - 47,63 R² = 0,931 (modelo linear). No capítulo II, foram testados dois modelos para todas as relações traçadas no experimento II, um modelo linear e um modelo quadrático, as relações foram consumo de matéria orgânica (CMO (g/UTM)) x digestibilidade da fibra em detergente neutro (DFDN), DMO x CMO (g/UTM), DMO x CMO (g/dia), consumo de folhas (g/UTM) x DMO e CMO (g/UTM) x relação proteína/energia. As relações que não foram estatisticamente significativas para nenhum modelo foram CMO (g/UTM) x relação proteína/energia e consumo de folhas (g/UTM) x DMO. Após essas relações, verificou-se que a PBf tem um bom potencial para a estimativa de consumo e a digestibilidade por bovinos alimentados com pastagens nativas ou associadas a forragem cultivada como o azevém anual, mas estes parâmetros também são afetados por diferentes variáveis. / In order to evaluate the fecal crude protein as intake and digestibility marker of cattle fed with natural pasture from Pampa Biome and annual ryegrass inclusions and evaluate the nutritional quality of these pastures it was conducted two experiments in metabolic cages. In the first experiment, the animals received different native pasture offer levels where treatments consisted of 1.5 and 2.25% of the live weight of dry matter and ad libitum with at least 20% of daily leftovers which were carried out six experimental periods. The second experiment consisted of annual ryegrass inclusion levels in the diet of cattle fed with natural pasture, the treatments were 33%, 66% and 100% of ryegrass to replace the native pasture in two experimental periods. The experiments were carried out in a completely randomized design with 3 treatments and 2 replicates per treatment in each period. The experimental period consisted of 10 days of adaptation and 5 days of collection during the period of the trough collects the forage offered have been sampled, the leftovers and also the total fecal production in each 24 hours. It was measured the fecal productions, concentration of faecal components, nutrient intake and digestibility of diet components. In the Chapter I were study the relationship between digestibility and fecal concentration of crude protein (CPf), being tested exponential and hyperbolic equations generating the digestibility of organic matter (OMD) = 0.709 - 9.506 * exp (- 0.041 * CPf) with R2 = 0.61 and OMD =0.942 - 38.619 / CPf (R2 0.62), respectively. The ratio of organic matter intake (OMI) with the amount of CPf, has a linear relation, it was then carried out stepwise analysis to find out what other variables could explain better the model along with the CPf generating a equation OMI = -6724.30 + 0,998 * CPf + 2.55 * NDFf + 11591.44 * OMD with R2= 0.95. It was determined the ratio of crude protein (CP) of the diet (g/kg of OM) x CPf (g/kg of OM), CPdiet = 1,346*CPf - 47.63 R² = 0.931 (linear model). In the Chapter II were tested two models for all relationships outlined in experiment II, a linear model and a quadratic model, relations were organic matter intake (OMI) x digestibility of neutral detergent fiber (DNDF), OMD x OMI, leaves intake x OMD and OMI x protein/energy ratio. The relationships that were not statistically significant for either model were OMI x protein/energy and leaves intake x OMD. After these relationships, it was found that the CPf has a good potential to estimate intake and digestibility in cattle fed native pastures or associated with annual ryegrass, but these parameters are also affected by different variables.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The forage intake was evaluated in beef heifers at grazing exclusive ryegrass (Lolium multiflorum Lam.) or receiving rice bran, with and without ionophore. We used the method of continuous grazing with variable number of animals. Rice bran in the proportion of 0.80% of body weight, was administered daily at 14 hours and showed levels of 13.80% crude protein (CP), 25.79% of neutral detergent fiber (NDF) and 12.45% ether extract (EE). The experimental design was completely randomized with repeated measures over time.Was used chromic oxide as a fecal production indicator. The dry matter intake was estimated using the technique of chromium oxide as an indicator of fecal output. The beef heifers grazing exclusively on pasture intake had a similar those receiving rice bran with or without monensin (2.63% of the BW in DM). The highest total dry matter intake was observed in heifers remained in ryegrass and received rice bran with addition of ionophore (3.42% of the BW in DM), intermediate in heifers that received rice bran (3.26% of the BW in DM) and remained lower in heifers grazing ryegrass (2.82% of the BW in DM). Average daily gain was higher for beef heifers receiving ionophore added to rice bran. The stocking rate was similar between food systems tested. / O consumo de forragem foi avaliado em novilhas de corte exclusivamente em pastagem de azevém (Lolium multiflorum Lam.) ou recebendo farelo de arroz integral, com e sem ionóforo. Foi utilizado o método de pastejo contínuo com número variável de animais. O farelo de arroz, na proporção de 0,80% do peso corporal,foi ministrado diariamente às 14 horas e apresentou teores de 13,80% de proteína bruta (PB), 25,79% de fibra em detergente neutro (FDN) e 12,45% de extrato etéreo (EE). O delineamento experimental foi o inteiramente casualizado, com medidas repetidas no tempo e foram estudadas variáveis do pasto e dos animais. O consumo de matéria seca foi estimado por meio de técnica do óxido de cromo como indicador da produção fecal. As novilhas exclusivamente em pastejo tiveram um consumo de pasto semelhante as que receberam farelo de arroz integral com ou sem monensina (2,63% do PC em MS). O maior consumo de matéria seca total foi observado nas novilhas que permaneceram em azevém e receberam farelo de arroz integral com adição de ionóforo (3,42% do PC em MS), intermediário nas novilhas que receberam farelo de arroz integral (3,26% do PC em MS) e inferior nas novilhas que permaneceram em pastagem de azevém (2,82% do PC em MS). O ganho médio diário foi superior para novilhas que receberam ionóforo adicionado ao farelo de arroz integral. A taxa de lotação foi semelhante entre os sistemas alimentares testados.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / New genotypes of ryegrass of other localities and with desirable characteristics are being commercialized as tool to reach better zoothenic performance indices. However, research must be carried through on its potentiality in the place to be implanted, searching to prevent problems in the growth and development of these fodder plants, compromising potential biomass yield. Thus, the objectives of this study for the cultivated genotypes of azevém at different times of sowings had been (1) was to estimate lower base temperature, it was also possible to investigate may have seasonal production; (2) to evaluate morphogenetic variables on three types of culms (main culm, first order tiller T1, and first order tiller T2) (3) productivity dry matter seed yield of the ryegrass of dual-purpose submitted. The experimental desing was a split-plot complete randomized block, with four block and treatments arranged in a three-factor (3x2x4) desing: three types of culms (main culm, first order tiller T1, and first order tiller T2), two genotypes (Comum and Advance) and four sowing dates (11/05, 07/06, 05/07 and 09/08/2007). The experimental desing was randomized block, and five ryegrass genotypes: three diploid (Comum, Fepagro São Gabriel, and LE 284 and two tetraploid (Avance and INIA Titán), the combination of number of cuts (from one at four), and five sowing dates (05/11, 06/07, 07/05, 08/09 and 09/01/2007). Values of Tb varied from 7.0 to 8.5ºC for the diploid genotypes and from 9.0 to 10.6ºC for the tetraploid genotypes, depending upon the method. Diploid ryegrass germoplasm have no risk of seasonal decrease in forage production, whereas tetraploids, mainly Avance, may have their growth and development decreased from June to August in Santa Maria because of minimum air temperature. The genotype Advance had the greatest accumulate leaf number and leaf appearance rate and the phyllochron were not different between the two genotypes. Main culm had the greatest leaf or final number and leaf appearance rate and the lowest phyllochron compared to tillers. Later sowing dates led to lower leaf blade elongation rate, final leaf number and leaf appearance rate and greater phyllochron. In all cuts and sowing dates, the leaves proportion was found to be higher in the tetraploids genotypes than in the diploids. The increase of cut number increased total dry matter yield and decreased seed yield, in all sowing dates and genotypes. Generally, the number of spike was small in tetraploids genotypes, bust the length of spike and seed, number and length of seed of spikelets and spacing between spikelets were larger. / Novos genótipos de azevém de outras localidades e com características desejáveis estão sendo comercializados como ferramenta para atingir melhores índices zootécnicos. Entretanto, devem ser realizadas pesquisas sobre sua potencialidade no local a ser implantado, buscando evitar problemas no crescimento e desenvolvimento dessas forragens, comprometendo produtividades. Assim, os objetivos deste estudo para os genótipos de azevém cultivados em diferentes épocas de semeaduras foram: (1) estimar a temperatura base e verificar se existe estacionalidade de produção; (2) estudar a morfogênese em três tipos de colmos (colmo principal e perfilhos de primeira ordem T1 e T2); (3) avaliar a produtividade da matéria seca da forragem e dos componentes do rendimento das sementes para o duplopropósito. O delineamento experimental adotado foi o blocos ao acaso. Foram utilizados cinco genótipos de azevém, três diplóides Comum, Fepagro São Gabriel e LE 284, e dois tetraplóides Avance e INIA Titán. Antes do diferimento para produção de sementes foram realizados cortes (variando de um até quatro cortes). Os genótipos foram cultivados em cinco épocas de semeadura (11/05, 07/06, 05/07, e 09/08 e 01/09/2007). A temperatura base inferior (Tb) para os genótipos diplóides de azevém foram menores, variam entre 7,0 a 8,5°C, que as dos tetraplóides, que variam de 9,0 a 10,6°C. As pastagens com genótipos diplóides de azevém não possuem riscos de estacionalidade de produção, mas com os tetraplóides, com destaque para o Avance, poderão ter seu crescimento e desenvolvimento reduzidos nos meses de junho a agosto em Santa Maria em função das temperaturas mínimas do ar. Os genótipos de azevém apresentaram taxa de surgimento de folhas e filocrono similares, mas o tetraplóide Avance em relação ao diplóide Comum possui maior número final de folhas e taxa de alongamento de folhas. O colmo principal de todos os genótipos possui maior número de final de folhas e menor filocrono em relação aos perfilhos. O avanço na época de semeadura determina menor taxa de alongamento de folhas, número final de folhas e taxa de surgimento de folhas e maior filocrono. Os genótipos tetraplóides de azevém apresentam maior proporção de folhas em todos os cortes e épocas de semeadura em relação aos diplóides. A realização de mais cortes nas pastagens dos genótipos diplóides e tetraplóides promovem maior matéria seca total e menor rendimento de sementes para todas as épocas de semeadura. De maneira geral, os genótipos tetraplóides caracterizam-se por apresentar menor número de espigas, e maior comprimento de espiga e sementes, número e comprimento de espigueta e espaçamento entre espigueta em relação aos diplóides.

Made available in DSpace on 2016-12-08T16:24:19Z (GMT). No. of bitstreams: 1 PGCA14MA143.pdf: 660934 bytes, checksum: 322caf24b166ea109317557fea920473 (MD5) Previous issue date: 2014-02-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The forage intake is determinant on animal performance and can be changed when more than one type of forage are used. The aim of this work was to assess the effects of corn silage supplementation + soybean meal (9:1 as DM basis) fed as a proportion of 10 g DM kg-1 LW, to wethers receiving ryegrass (Lolium multiflorum Lam.) haylage with two forage offers: ad libitum or restrict amount, (60% of ad libitum DM intake). Eight wethers (average 31.5±2.2 kg of body live weight, LW) were used in a replicated 4 × 4 Latin Square design. Each experimental period conducted over 19 d, with a 14 of adaptation and 5 of measurements. Animals were fed three times a day (08:00h, 11:30h and 16:30h). Supplemented animals received corn silage at 08:00h and ryegrass haylage at 11:30h and 16:30h. The substitution rate was 0.93 in supplemented group ad libitum and zero in animal receiving restricted amount of ryegrass haylage. The digestible OM intake and N retention were similar in animals receiving ryegrass haylage ad libitum, but increased when ryegrass haylage was restricted. However, even with the supplementation animals receiving restricted amount of ryegrass haylage showed lower OM digestible intake and N retention compared to animals average of receiving ryegrass ad libitum. The OM digestibility and efficiency of rumen microbial protein synthesis were not affected by treatments, but the NDF and ADF digestibility were lower in supplemented animals compared to unsupplemented ones and in restricted compared to ad libitum diets. The corn silage supplementation could not be enough to avoid reductions on OM digestible intake and N retention to wethers receiving restrict amounts of ryegrass haylage / O consumo é determinante no processo produtivo, e pode ser modificado, quando é fornecido mais de um tipo de forragem na dieta. O objetivo deste trabalho foi avaliar os efeitos da suplementação com silagem de milho + farelo de soja (9:1 com base na MS) na proporção de 10 g de MS/kg PV, para cordeiros recebendo silagem pré-secada de azevém (Lolium multiflorum Lam) em duas ofertas de forragem: à vontade ou restrito (60% do consumo à vontade). Oito ovinos machos castrados cruza Texel × Crioula (média de 31,5 ± 2,2 kg de peso vivo, PV) foram usados em um delineamento experimental em Quadrado Latino 4 × 4. Cada período experimental foi realizado durante 19 dias, com 14 de adaptação e 5 de medidas. Os animais foram alimentados três vezes ao dia (08:00 h, 11:30 h e 16:30 h). Animais suplementados receberam silagem de milho às 08:00 h e silagem pré-secada de azevém às 11:30 h e às 16:30 h. As taxas de substituição foram 0,93 nos animais com oferta de azevém à vontade e zero nos que recebiam o mesmo em quantidade restrita. O consumo de MO digestível e a retenção nitrogenada não variaram com a suplementação nos animais que receberam o azevém à vontade, mas aumentaram nos animais com oferta restrita. Contudo, os animais com oferta restrita e suplementados tiveram menor consumo de MOD e retenção nitrogenada que a média dos que receberam azevém à vontade. A digestibilidade da MO e a eficiência de síntese de proteína microbiana não foram afetadas pelos tratamentos, mas a digestibilidade do FDN e FDA foi menor nos animais suplementados em comparação aos não suplementados e nos de oferta restrita em comparação a oferta à vontade. Mesmo com a suplementação, a restrição alimentar da forragem de base pode limitar a ingestão diária de MO digestível e a retenção diária de N em ovinos

Made available in DSpace on 2016-12-08T16:44:47Z (GMT). No. of bitstreams: 1 PGPV14MA144.pdf: 861442 bytes, checksum: c0bd112f70401acc3674e49bcc979cf3 (MD5) Previous issue date: 2014-07-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of the present work is to analyze the response of plants of ryegrass (Lolium multiflorum) and wavy-leaved fleabane (Conyza bonariensis) to increasing doses of glyphosate to detect herbicide susceptible and resistant biotypes and to evaluate the physiological quality of seeds of these biotypes to verify the relationship between the resistance and the physiological seed quality of these weeds. Ryegrass and wavy-leaved fleabane plants were exposed to increasing doses of glyphosate, ranging from 0 up to 1440 g ae ha-1, and the fresh weight were weighted 21 days after application, for dose-response tests. Seeds were subjected to tests of physiological quality (germination, cold test and accelerated aging). The experimental design was completely randomized, using ten replicates for ryegrass and six replicates for wavy-leaved fleabane in the dose-response tests, and four replicates for tests of physiological seed quality. All studied biotypes of ryegrass and wavy-leaved fleabane showed differential response due to increasing doses of glyphosate. Ryegrass resistant biotypes showed resistance factors (RF) of 3.0 (Passo Fundo) and 8.3 (Vacaria), while the susceptible ones showed FR of 1.5 (Ponte Serrada) and 1.0 (Lages). Wavy-leaved horseweed resistant biotypes showed FR 2.0 (Papanduva) and 15.5 (Campos Novos), and the susceptible biotype FR 1.0 (Lages). In the tests of physiological seed quality, ryegrass biotype of Lages showed the best performance for germination (64%) and accelerated aging (86%) tests compared to the other biotypes. For the cold test, the biotype of Vacaria showed the best result with 86% of germination, while the biotype of Passo Fundo showed the worst results in all tests. Biotypes of wavy-leaved fleabane did not differ in germination. For Lages and Papanduva wavy-leaved fleabane, itwas found the biotypes responded positively to cold stress (66 and 61%, respectively). The biotype of Campos Novos, with high resistance to the herbicide, did not withstand the stress exposure, presenting similar to germination (34%) compared to the cold test (28%) result. The seeds of the wavy-leaved fleabane biotypes responded negatively to accelerated aging, in that the biotype of Lages showed the best result (12%), while biotypes of Papanduva and Campos Novos showed 4.0 and 2.0%, respectively. Biotypes of ryegrass with differential response to glyphosate present distinct percentage of germination and vigor of seeds, although it is not directly dependent on herbicide resistance. Susceptible biotypes of wavy-leaved fleabane and the biotype with low degree of resistance to glyphosate are more vigorous than the resistant biotype. The physiological seed quality of ryegrass and wavy-leaved fleabane is not directly related to the resistance to glyphosate, and the influence of environment is probably more significant than the resistance / Objetivou-se com o presente trabalho analisar a resposta de plantas de azevém (Lolium multiflorum) e buva (Conyza bonariensis) a doses crescentes do glyphosate para detecção de biótipos suscetíveis e resistentes ao herbicida e avaliar a qualidade fisiológica de sementes desses biótipos para verificar a relação entre a resistência e a qualidade fisiológica de sementes dessas plantas daninhas. Plantas de azevém e buva foram expostas a doses crescentes de glyphosate, variando de 0 a 1.440 g e.a. ha-1, com avaliação da massa fresca após 21 dias da aplicação. As sementes foram submetidas a testes de qualidade fisiológica (germinação, teste de frio e envelhecimento acelerado). O delineamento experimental utilizado foi o inteiramente casualizado, com dez repetições para o azevém e seis repetições para a buva no teste de dose-resposta e com quatro repetições para os testes de qualidade fisiológica de sementes. Todos os biótipos estudados de azevém e buva apresentaram resposta diferencial ao aumento de dose do herbicida glyphosate. Os biótipos de azevém resistentes apresentaram fatores de resistência (FR) igual a 3,0 (Passo Fundo) e 8,3 (Vacaria) enquanto os susceptíveis 1,5 (Ponte Serrada) e 1,0 (Lages). Os biótipos de buva resistentes apresentaram FR de 2,0 (Papanduva) e 15,5 (Campos Novos) e o biótipo susceptível FR de 1,0 (Lages). Nos testes de qualidade fisiológica o biótipo de azevém de Lages apresentou melhor desempenho para os testes de germinação (64%) e envelhecimento acelerado (86%) em relação aos demais biótipos. Para o teste de frio, o biótipo de Vacaria apresentou o melhor resultado com 86%. Enquanto que o biótipo de Passo Fundo apresentou os piores resultados em todos os testes realizados. Os biótipos de buva não se diferenciaram no teste de germinação. Para os biótipos Lages e Papanduva foi verificado que o vigor desses biótipos responderam positivamente ao estresse pelo frio (66 e 61% respectivamente). O biótipo de Campos Novos, com elevada resistência ao herbicida, não suportou a exposição ao estresse, apresentando resultado semelhante ao teste de germinação (34%) em relação ao teste de frio (28%). As sementes dos biótipos de buva responderam negativamente ao teste de envelhecimento acelerado, em que o biótipo de Lages apresentou o melhor resultado com 12%, enquanto os biótipos de Papanduva e Campos Novos apresentaram 4,0 e 2,0% respectivamente. Os biótipos de azevém com resposta diferencial ao glyphosate apresentam porcentagem de germinação e vigor de sementes distintos, porém não diretamente dependentes da resistência ao herbicida. Os biótipos de buva suscetível e com baixo grau de resistência ao herbicida glyphosate são mais vigorosos que o biótipo resistente. A qualidade fisiológica de sementes de azevém e buva não está diretamente relacionada com a resistência ao herbicida glyphosate, sendo a influência do ambiente, provavelmente, mais significativa do que a resistência

Made available in DSpace on 2014-08-20T14:06:13Z (GMT). No. of bitstreams: 1 Dissertacao_Adriana_Bresolin.pdf: 2384605 bytes, checksum: 22ab5737435e4daf2df75c2d58721a14 (MD5) Previous issue date: 2007-04-05 / Italian ryegrass (Lolium multiflorum Lam.) is the most important forage grass in Rio Grande do Sul, as well as in most part of temperate and subtropical regions of the world. Due to its importance, in 1999 Embrapa Temperate Agriculture initiated activities to develop an Italian ryegrass breeding program, which started with collecting germplasm in Southern Brazil. However, collecting and conservation of germplasm, without its characterization, results in genebanks as simple repositories of genetic materials, without use. To established correct strategies of efficient management and use of genebanks, is extremely important to know the amount and quality of genetic resources available in genebanks. This study was developed aiming to evaluate Italian ryegrass populations to aluminum tolerance and to establish the optimum bulk size to estimate genetic diversity among populations with AFLP markers. Two experiments were undertaken; the first one evaluated six Italian ryegrass populations in hydroponic solution to aluminum (Al3+) tolerance. The results showed that the nutrition solution combined with the different aluminum doses (0; 7 and 21 mg.L-1) were efficient to discriminate the populations evaluated, showing the presence of genetic variability among populations. Tolerance to Al3+ was higher in populations CNPGL 136 and CNPGL 178, which also showed stability in both periods of evaluation. The second experiment was developed aiming to establish the optimum bulk size to estimate genetic diversity among Italian ryegrass populations with AFLP markers. Two populations were evaluated; from each population were characterized 30 individuals and the respective bulk samples sizes: six bulks of 5 individuals each; three bulks of 10 individuals; two bulks of 15 individuals; one bulk of 20 individuals and one bulk of 30 individuals. Six AFLP primer combinations were employed. All numbers and sizes of bulks evaluated were able to discriminate the two populations characterized. However, considering time, cost and discriminatory power, the bulk of 20 individuals is more indicated to be employed in genetic diversity analysis studies among Italian ryegrass populations. Although alleles that occur in low frequency in the populations are lost when bulks are analyzed, the evaluation of bulks, instead of individual genotypes, saves processing time of samples allows that a larger number of populations to be analyzed without identity losses. / O azevém (Lolium multiflorum Lam.) é a espécie forrageira de maior utilização no Rio Grande do Sul, assim como na maior parte das regiões temperadas e subtropicais do mundo, destacando-se entre as mais difundidas no mundo. Devido à grande importância desta forrageira no Brasil, no ano de 1999, iniciaram-se na Embrapa Clima Temperado atividades voltadas ao melhoramento do azevém anual, inicialmente com a realização de coletas de germoplasma. No entanto, a simples coleta e a conservação de recursos genéticos, sem as informações sobre suas características, torna os bancos de germoplasma simples depósitos de materiais. É de fundamental importância que se conheçam os recursos genéticos disponíveis, tanto em termos da variabilidade presente, como em termos de qualidade destes materiais, para que uma apropriada definição das estratégias de conservação e uso seja empregada. A pesquisa teve como principais objetivos avaliar populações de azevém anual quanto à tolerância ao alumínio tóxico e definir o tamanho de amostras de bulks de DNA mais apropriado para estudos de diversidade genética entre populações de azevém anual com marcadores AFLP. Foram desenvolvidos dois trabalhos: o primeiro avaliou populações de azevém sob condições de hidroponia quanto à sensibilidade e tolerância ao alumínio. Os resultados encontrados mostram que o emprego de solução nutritiva combinada com as diferentes doses de Al3+ (0; 7 e 21 mg.L-1) foi eficiente na discriminação dos genótipos em estudo, indicando a existência de variabilidade genética e destacando as populações CNPGL 178 e CNPGL 136 como constituições genotípicas com maior tolerância ao alumínio e estabilidade nos dois períodos de avaliação. O segundo tratou de definir o tamanho de bulk mais apropriado para estimar a diversidade genética entre populações de azevém com uso de marcadores AFLP. Foram avaliadas duas populações de azevém, sendo analisados 30 indivíduos de cada população e seus respectivos bulks: seis bulks constituídos por 5 indivíduos cada; três bulks de 10 indivíduos; dois bulks de 15 indivíduos; um bulk de 20 indivíduos e um bulk de 30 indivíduos. Seis combinações de primers AFLP foram empregadas. Todos os tamanhos e número de bulks avaliados foram eficientes em discriminar as duas populações analisadas. Entretanto, considerando a rapidez, custo e poder discriminatório, o bulk formado por 20 indivíduos foi o mais apropriado para estimar a divergência genética entre populações de azevém. Foi evidenciado que embora ocorra uma perda dos alelos que estão presentes em baixa freqüência nas populações, a avaliação de bulks acarreta na redução de amostras a serem processadas, permitindo que um grande número de populações sejam caracterizadas sem perder a identidade de cada população.