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Cereals represent one of the most important food crops in the world. Rice (Oryza sativa) is one of the most commonly consumed cereal grains, and as a result, has considerable economic and agricultural importance, despite their potential as a source of genetic material. The phylogenetic relationships among rice and its wild species are not well understood. The objectives of this study are to evaluate the rate and type of molecular variation present in the gene that encodes the 10 kDa prolamin polypeptide in Oryza (Poaceae), and use this information in understanding the evolution of the Oryza genus. Our principle hypothesis is that genetic diversity exists at the molecular level in wild species of Oryza, and that this diversity can provide useful information regarding the phylogenetic relationships among rice species and permit a more theoretical examination of the evolutionary processes, such as concerted evolution, within Oryza and its nine genomes. A phylogeny of Oryza is presented, and modes of evolution are discussed. / Master of Science

BACKGROUND:Tef (Eragrostis tef), an indigenous cereal critical to food security in the Horn of Africa, is rich in minerals and protein, resistant to many biotic and abiotic stresses and safe for diabetics as well as sufferers of immune reactions to wheat gluten. We present the genome of tef, the first species in the grass subfamily Chloridoideae and the first allotetraploid assembled de novo. We sequenced the tef genome for marker-assisted breeding, to shed light on the molecular mechanisms conferring tef's desirable nutritional and agronomic properties, and to make its genome publicly available as a community resource.RESULTS:The draft genome contains 672 Mbp representing 87% of the genome size estimated from flow cytometry. We also sequenced two transcriptomes, one from a normalized RNA library and another from unnormalized RNASeq data. The normalized RNA library revealed around 38000 transcripts that were then annotated by the SwissProt group. The CoGe comparative genomics platform was used to compare the tef genome to other genomes, notably sorghum. Scaffolds comprising approximately half of the genome size were ordered by syntenic alignment to sorghum producing tef pseudo-chromosomes, which were sorted into A and B genomes as well as compared to the genetic map of tef. The draft genome was used to identify novel SSR markers, investigate target genes for abiotic stress resistance studies, and understand the evolution of the prolamin family of proteins that are responsible for the immune response to gluten.CONCLUSIONS:It is highly plausible that breeding targets previously identified in other cereal crops will also be valuable breeding targets in tef. The draft genome and transcriptome will be of great use for identifying these targets for genetic improvement of this orphan crop that is vital for feeding 50 million people in the Horn of Africa.

Microparticles (KEMs) made from the sorghum prolamin protein, kafirin, have internal vacuoles. Hence, they have potential as delivery vehicles for nutraceuticals. However, their physico-chemical properties need to be improved for this application. The influence of kafirin extracted from white tan-plant and red non-tannin sorghum types of 81% and 84% protein content respectively and the rate of water addition on the formation of KEMs from kafirin in acetic acid solution by coacervation on their morphology was investigated. A water flow rate of 1.4 and 0.7 ml/min during coacervation using 81% kafirin resulted in spherical-shaped KEMs between 1 and 10 μm in diameter and vacuoles up to 2 μm. KEMs made with 84% kafirin at a flow rate of 0.7 ml/min were large and oval-shaped with an average length and width of 43 and 21 μm respectively and numerous vacuoles up to 3 μm. At a flow rate of 1.4 ml/min, the KEMs were oval-shaped with larger vacuole sizes (5 μm), a length and width of 91 and 30 μm respectively. However, SDS-PAGE indicated that neither the source of kafirin, nor the conditions of microparticle preparation had an effect on KEMs protein molecular size.As the presence of phenolic compounds in the kafirins might have been responsible for the differences in KEMs morphology, the effect of sorghum-derived polyphenols (extracted from condensed-tannin and non-tannin black sorghum brans) on the physico-chemical properties of KEMs was then investigated using 81% kafirin. Aqueous condensed tannin (10.1 mg CE (catechin equivalent)/100 mg extract) and black non-tannin (4.6 mg CE/100 mg extract) extracts in varying concentrations, were substituted for the water used for coacervation. KEMs made with condensed tannin extracts were oval-shaped and much larger, than control KEMs ranging from 20 to 400 μm, with rough surfaces and enlarged vacuoles. The enlarged vacuoles were probably due to more air being trapped within the particles during formation. However, KEMs made from non-tannin phenolic extracts were smaller and spherical with average diameters up to 18 μm. Tannins are known to bind strongly to kafirin through hydrogen and hydrophobic bonds, which probably resulted in the larger microparticles. The KEMs made from condensed tannins also had high antioxidant capacities compared to KEMs made from non-tannin phenolic extracts, attributed to tannins being more potent antioxidants. Thus, condensed tannin extracts are the most beneficial as they contributed towards the antioxidant activity of the KEMs, resulting in the development of innovative KEMs with added antioxidant benefits and enlarged size. / Dissertation (MSc)--University of Pretoria, 2013. / gm2014 / Food Science / unrestricted

Submitted by NAIARA CAIXETA DA SILVA null (naiaranoemi@bol.com.br) on 2016-12-21T12:13:24Z No. of bitstreams: 1 Tese_Naiara_Caixeta_da_Silva.pdf: 1682545 bytes, checksum: ca3b83a01f9c9a072da78273e4da0fca (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-12-21T12:43:25Z (GMT) No. of bitstreams: 1 silva_nc_dr_jabo.pdf: 1682545 bytes, checksum: ca3b83a01f9c9a072da78273e4da0fca (MD5) / Made available in DSpace on 2016-12-21T12:43:25Z (GMT). No. of bitstreams: 1 silva_nc_dr_jabo.pdf: 1682545 bytes, checksum: ca3b83a01f9c9a072da78273e4da0fca (MD5) Previous issue date: 2016-10-28 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Foram conduzidos três experimentos com os objetivos de determinar 1) a melhor dose e tipo de inoculante, homo ou heterofermentativo, para grão de milho reidratado; 2) os efeitos do tempo de estocagem e do uso de inoculante sobre o perfil fermentativo, estabilidade aeróbia e degradabilidade in situ de silagem de milho grão úmido e silagem de grão de milho reidratado; 3) as alterações nos parâmetros ruminais, digestibilidade e desempenho de bovinos Nelore, consumindo dietas contendo milho seco moído ou silagem de milho grão úmido ou silagem de grão de milho reidratado sem e com o uso de inoculante. No experimento 1 foi avaliado silagem de grão de milho reidratado sem inoculante (C), com L. plantarum + P. acidilactici (LPPA) e com L. buchneri (LB), ambos nas doses de 1 ×105, 5 ×105 e 1 ×106 ufc/g, estocadas por 124 dias. As silagens inoculadas com LB em relação ao C apresentaram maior (P < 0,01) contagem de bactérias ácido láticas (BAL), concentração de ácido acético, ácido propiônico e 1,2-propanodiol e menor (P < 0,01) pH, leveduras e fungos filamentosos nos 12 dias de exposição ao ar e maior (P < 0,01) estabilidade aeróbica, isso ocorreu já na primeira dose (1 ×105 ufc/g). O uso de LB também aumentou (P < 0,05) a quebra de prolamina e a degradabilidade in situ das silagens. Uso de LPPA não apresentou melhorias na fermentação e piorou a deterioração aeróbia em comparação ao controle. No experimento 2 foi avaliado um esquema fatorial 2 × 2, sendo o primeiro fator dois tipos de ensilagem, silagem de milho úmido (MU) e silagem de milho reidratado (MR); e o segundo fator o uso de inoculante, sem (Controle) e com L. buchneri (LB; 1 × 105 ufc/g), com aberturas aos 15, 30, 60, 90, 120, 180, 240 e 300 dias de estocagem. A MR apresentou maior concentração total de ácidos, enquanto as silagens com LB apresentaram maior concentração de ácido acético e 1,2-propanodiol e menor de ácido lático e ácido butírico. Ao longo dos tempos de estocagem, MU LB e MR LB apresentaram menor contagem de leveduras e maior contagem de BAL e estabilidade aeróbia. A MR com tamanho de partícula original apresentou maior degradabilidade in situ que a MU. O tempo mínimo para atingir ganhos altos de degradabilidade foi entre 30 e 70 dias de estocagem. No experimento 3 foram avaliadas cinco dietas contendo: silagem de milho grão úmido (MU), silagem de milho grão úmido com L. buchneri (MUB), silagem de grão de milho reidratado (MR; 1 × 105 ufc/g), silagem de grão de milho reidratado com L. buchneri (MRB; 1 × 105 ufc/g) e milho seco moído (MSC). No experimento de metabolismo foram utilizados 10 animais fistulados, agrupados em dois quadrados latinos (5 × 5), enquanto no experimento de desempenho foram utilizados 180 animais Nelore (310±17 kg), sendo 6 animais por baia e 6 baias por tratamento. Os animais que consumiam silagens apresentaram maior (P < 0,05) digestibilidade da MS, MO e PB; maior concentração de propionato e ácidos graxos de cadeia curta totais; menor (P < 0,01) CMS e pH ruminal; e maior (P < 0,01) eficiência alimentar, ELm e ELg da dieta em relação aos animais consumindo MSC. O uso de L. buchneri aumentou a estabilidade aeróbia, e o tempo de estocagem aumentou a degradabilidade das silagens. Recomenda-se o uso de silagens de grãos de milho por propiciar melhor digestibilidade e eficiência alimentar. A silagem de grão de milho reidratado é uma alternativa à silagem de milho grão úmido. / Three trials were conducted with the objective to determine 1) the best dose and type of inoculant, homo or hetero fermentative, for reconstituted corn grain silages; 2) the effects of storage time and the use of inoculant on the fermentation profile, aerobic stability and in situ degradability of high moisture and reconstituted corn grain silages; 3) changes in ruminal fermentation, digestibility and performance of Nellore steers fed diets containing dry ground corn or high moisture or reconstituted corn grain silages without and with inoculant. In trial 1, treatments were: reconstituted corn grain silages without inoculant (C), L. plantarum + P. acidilactici (LPPA) and L. buchneri (LB), both at doses of 1 × 105, 5 × 105 or 1 × 106 cfu/g, stored for 124 days. Silages inoculated with LB compared to C had greater (P < 0.01) count or lactic acid bacterial (LAB), acetic acid, proprionic acid and 1,2-propanediol concentrations and lower (P < 0.01) pH, yeasts and molds for 12 days of exposure to air and higher (P < 0.01) aerobic stability, this occurs already at the first dose (1 x 105 cfu/g). The use of LB also increased (P < 0.05) proteolysis and in situ degradability of silages. The LPPA showed no improvements in fermentation and increased mold counts during the aerobic stability. The trial 2 was designed in a 2 × 2 factorial arrangement: two types of silage, high moisture corn (HMC) or reconstituted corn grain silages (RCS); and without (control) or with L. buchneri (LB; 1 × 105). Silos were opened after 15, 30, 60, 90, 120, 180, 240 and 300 days of storage. The RCS showed higher overall concentration of acids, while silages inoculated with LB had greater concentrations of acetic acid and 1,2-propanediol and lower content of lactic and butyric acids. Along the storage time, HMC LB and RCS LB showed lower yeast count and higher BAL count and aerobic stability. The RCS with original particle size showed higher in situ degradability than HMC. The minimum length of storage to reach high degradability of gains is between 30 and 70 days of storage. In trial 3 were evaluated five diets: high moisture corn (HMC), HMC with L. buchneri (HMCLB), reconstituted corn grain silages (RCS), RCS with L. buchneri (RCSLB) and dry ground corn (DGC). We used 10 cannulated bulls in a metabolism experiment, assigned in two latin squares (5 × 5), and 180 Nellore bullocks (310±17 kg) in the performance experiment, with 6 animals per pen and 6 pens per treatment. Animals fed silages had higher (P < 0.05) DM, OM and CP digestibility, greater concentrations of propionato and total short-chain fatty acids, and lower (P < 0.01) DMI, rumen pH and higher (P < 0.01) feed efficiency, NEm and NEg for the diet for the animals consuming DGC. The use of L. buchneri increases aerobic stability and storage time increases the degradability of silages. It is recommended the use of corn grain silages by providing better digestibility and utilization of diet. Reconstituted corn grain silages is an alternative to the high moisture corn silage. / FAPESP: 2013/16720-2

The only treatment for coeliac disease, a common autoimmune disorder, is life-long adherence to a gluten-free diet. However, the replacement of wheat gluten, a key structural and functional component in bread, poses a major technological challenge for food scientists. The use of non-wheat cereal proteins, as alternatives to gluten, shows much promise in gluten-free bread making. Literature has shown that when zein, the maize prolamin protein, is subjected to wet heat above its glass transition temperature (Tg), the protein becomes viscoelastic, rubbery and dough-like. Gluten-like fibrils are visible, which form complex protein networks similar to those found in wheat dough. The resulting zein dough has viscoelastic characteristics and can be successfully used with hydrocolloids to produce gluten-free bread. This project examined the influence of wet heat treatment and dilute organic acids (lactic acid and acetic acid) on the dough-making quality of non-wheat cereal proteins, such as kafirin and zein. Zein was the only non-wheat cereal protein to show any physical change when it was subjected to wet heat treatments, forming a dough-like substance. Acidification of the zein dough prepared at 40°C with concentrations of 0.7, 1.3 and 5.4% (v/v) organic acid in distilled water solutions, showed that the higher the concentration of acid used, the greater its effect on the dough's rheological properties. Tensile tests using a Keifer rig on zein dough showed that as the concentration of organic acid was increased from 0.7 to 1.3 and to 5.4% (v/v) the dough become softer and increasingly more extensible. The dough also exhibited less resistance to extension and reduced elasticity. CLSM revealed that the zein doughs contained a protein network, made up of fine protein fibrils, which became smoother and more homogenous as the concentration of acid was increased. Although SDS-PAGE revealed that no oligomerization took place with acid addition, iv FTIR showed that zein dough prepared with distilled water at 40°C had elevated levels of β-sheets. When organic acids were added in increasing levels, corresponding increases in the quantities of α-helices in the protein were observed. Alveography showed that zein-based doughs prepared with dilute organic acids retained gases well and that the concentration of dilute organic acids influenced dough distensibility (biaxial extensibility) and stability (the ability of the dough to retain gas). Low concentration of acids (0.7 and 1.3%) increased dough stability to levels similar to that of strong wheat flour, 103 mm H2O, but higher concentrations of acids (5.4%) led to a marked reduction in dough stability. Thus, by increasing zein dough functionality to such an extent, the apparent usefulness of the doughs and their ability to retain gases produced during fermentation is reduced. Simple distensibility tests on zein doughs showed that added organic acids promoted ‘clumping’ of the fine protein fibrils in the dough network into pronounced fibres. This would account for the decreased dough stability when high levels (5.4%) of organic acids were used. Baking trials with zein doughs were not successful as adequate leavening was impossible without an acid-tolerant leavening agent. It is believed that dilute organic acids influence the rheological properties of zein dough by creating a positively charged environment, in which the protein is partially solubilized. The higher the level of organic acid used, the greater the positive net charge and the more pronounced the effect on the protein network structure. Organic acids could also improve fluidity of the zein dough by acting as plasticizers. From this work it can be seen that although a protein network is present in all zein-based doughs, the ability of this network to retain gases is dependant on the level of organic acids present. The functional properties of zein-doughs made with low levels of organic acids (0.7 and 1.3%) shows potential in the production of gluten-free bread for individuals suffering from coeliac disease. / Dissertation (MSc)--University of Pretoria, 2013. / gm2014 / Food Science / unrestricted

No experimento I, objetivou-se avaliar os efeitos de aditivos microbianos e tempo de armazenamento na qualidade de silagens de milho. A cultura do milho foi ensilada sem aditivos (Controle) ou com inoculantes contendo bactérias láticas homofermentativas (Lactobacillus plantarum + Enterococcus faecium + Pediococcus acidilactici) + enzimas celulolíticas e hemiceluloliticas ou heterofermentativas (Lactobacillus buchneri) aplicados na dose 1 × 105 ufc/g. As silagens foram armazenadas em silos experimentais durante 3, 7, 15, 30, 60, 210, 390, 480 ou 570 dias. Foram avaliados: composição químico-bromatológica, produtos de fermentação, perfil microbiológico, perdas fermentativas, estabilidade aeróbia e degradabilidade ruminal in situ. Os inoculantes não afetaram a maior parte das variáveis estudadas. Entretanto, L. buchneri aumentou a concentração de ácido acético das silagens e diminuiu a deterioração aeróbia, confirmada pelo menor acúmulo térmico durante o ensaio de estabilidade aeróbia. O teor de carboidratos solúveis diminuiu ao longo do tempo de armazenamento, reflexo do metabolismo dos açúcares em produtos de fermentação. As concentrações da prolamina como esperado diminuíram e as concentrações de nitrogênio amoniacal e proteína solúvel aumentaram com os tempos de armazenagem prolongados, reflexo da ocorrência de proteólise na silagem de milho. O pH da silagem diminuiu rapidamente nos primeiros sete dias de armazenamentos mantendo-se estável para os demais tempos de estocagem, diferente do ocorrido para a concentração de ácido acético, que aumentou com o tempo de armazenamento. Verificou-se diminuição na contagem de bactérias láticas e leveduras ao longo do armazenamento. A produção de gás e a perda de matéria seca aumentaram com o tempo de armazenamento. O tempo de armazenamento aumentou todas as variáveis de EA. Os ganhos mais significativos para a EA se deram até aproximadamente 60 dias de armazenamento. A degradação ruminal de amido e, consequentemente de MS, foi incrementada ao longo do armazenamento. No experimento II, objetivou-se avaliar o desempenho de vacas leiteiras em função da estratégia de descarregamento da silagem de milho em silo do tipo trincheira: silagem de milho oriunda da metade superior do silo (topo) ou silagem de milho oriunda da metade inferior do silo (base). Foram utilizadas 24 vacas alocadas em 12 blocos casualisados, com arranjo de reversão simples com períodos de 21 dias. Os animais foram alojados em confinamento tie-stall. As dietas foram iso-protéicas (16,5%) e iso-amiláceas (17,0%), com 60% de silagem de milho (% MS). O consumo de matéria seca, produção e composição do leite foram determinados entre os dias 15 e 21 de cada período experimental. Apesar da silagem oriunda da base do silo levar à maior digestibilidade da dieta e menor concentração de nitrogênio ureico do leite (8,95 e 11,35 mg/dL) não houve efeito da dieta no consumo de matéria seca nem na produção de leite. Sob condições ótimas de manejo, a estratégia de descarregamento da silagem de milho não afeta o desempenho de vacas leiteiras. / In the experiment I, the aim was to evaluate the effects of microbial additives and length of storage on the quality of corn silage. Whole-corn plants were ensiled without or with inoculants containing homofermentative (Lactobacillus plantarum + Enterococcus faecium + Pediococcus acidilactici + cellulolytic and hemicellulolytic enzymes) or heterofermentative lactic acid bacteria (Lactobacillus buchneri) applied at 1 × 105 cfu/g. Treated forages were packed and stored in experimental silos for 3, 7, 15, 30, 60, 210, 390, 480, and 570 days. Samples were evaluated for chemical composition, fermentation end-products, microbial counts, fermentation losses, aerobic stability, and ruminal degradability in situ. Inoculants did not affect most of the variables studied. However, L. buchneri increased acetic acid concentration and decreased aerobic deterioration of silages, as indicated by the lower heat accumulation during the exposure to air. Soluble carbohydrates decreased across the storage period, reflecting the conversion of soluble sugars to fermentation end-products. Concentrations of prolamin decreased, whereas ammonia and soluble protein concentrations increased over the storage period, indicating the proteolysis. The silage pH declined rapidly in the first seven days of storage and remained stable for the remaining storage period, unlike for acetic acid concentration that increased with storage period. On the other hand, counts of lactic acid bacteria and yeasts decreased during the storage. Gas production and dry matter loss increased with the length of storage. The storage period increased all variables stability aerobic. Most of significant improvements in stability aerobic were observed during the first 60 days of storage. Ruminal degradability of starch and, consequently, dry matter increased along the storage. In the experiment II, the aim was to evaluate the influence of strategy of silage unload on the performance of dairy cows. Corn silage from a bunker silo was separated at unloading as silage from the upper half of the silo (top) or from the lower half of the silo (bottom) and used to compose total mixed rations fed to 24 lactating cows allocated in 12 randomized blocks, arranged in a cross-over design with 21 periods. Cows were housed in a tie-stall barn. All diets contained 60% of corn silage and were iso-nitrogen (16.5% CP) and iso-starch (17.0% of starch). Dry matter intake, milk yield and composition were determined from day 15 to 21 in each period. Although silage from bottom led to higher total tract DM digestibility and lower milk urea nitrogen concentration (8.95 vs. 11.35 mg/dL), most of evaluated variables were not affected by treatments. Under optimal silo management, the strategy used to unload corn silage does not affect the performance of dairy cows.

Made available in DSpace on 2014-07-29T15:16:28Z (GMT). No. of bitstreams: 1 Dissertacao SantosKFD.pdf: 3452223 bytes, checksum: 425b2eff60093d958263e376587dc3c7 (MD5) Previous issue date: 2010-03-31 / The objective of this dissertation was to analyze quantitative and qualitatively the total storage protein content and its fractions albumin, globulin, prolamin and glutelin from the grain of 29 genotypes of the wild rice Oryza glumaepatula and 70 interspecific lines backcross 2 obtained from the cross O. sativa x O. glumaepatula. From these lines, 34 BC2F8 were obtained from the cross O. sativa BG 90-2 x O. glumaepatula RS-16 and 36 BC2F10 were obtained from the cross O. sativa CICA-8 x O. glumaepatula RS-16. From the analysis of variance for the total protein content and its fractions, it were found highly significant differences (P<0.01) between the wild genotypes and the interspecific lines. The average of total protein content of wild genotypes was 12.17%, whereas the lines of BG 90-2 x RS-16 showed an average of 7.05% and the lines of CICA-8 x RS-16 showed an average of 8.40%. The wild genotype BGA14280 showed the highest total protein content (14.94%). In the comparative analysis of interspecific lines and their parents, it were found five lines with higher total protein content (average of 10.95%), which was significantly superior to the cultivated parent BG 90-2 (10.0%) and CICA-8 (9.61%). However, these lines showed lower content in relation to the wild parent RS-16 (14.06%). In relation to the protein fractions, 40 interspecific lines showed higher values in relation to their parents, excepting in one occasion, where the wild parent RS-16 showed higher value to the glutelin fraction. Considering the 29 wild genotypes, it were found the highest contents of albumin, prolamin and glutelin, excepting to the globulin fraction, where the wild genotype was not significantly different from the cultivar BRS Bonança. The SDS-PAGE analyses of the total protein and the glutelin fraction showed a differential profile of &#945;-glutelins for the wild genotypes, emphasizing the BGA14232 genotype, which did not showed the &#945;-polypeptides commonly identified in the remaining genotypes. Considering the interspecific lines and their parents, it was found similar profile of total protein and &#945;-globulins, with differences in relation to the 40 kDa &#945;-glutelin, which was found just in the wild parent RS-16, indicating a differential expression in O. glumaepatula, since the O. sativa showed a 39 kDa &#945;-glutelin. In relation to albumin, globulin and prolamin fractions, the wild genotypes showed a different protein profile in comparison to the interspecific lines and the cultivated rice, probably due to the two crosses in direction to BG 90-2 and CICA-8, which were the recurrent parents during the interspecific lines development. The highest protein content found to the O. glumaepatula, the different protein profile and the finding of interspecific lines with higher protein content in relation to their cultivated parents clearly show the positive contribution of this species to the genetic breeding aiming the increase of the nutritional value for the grain of the cultivated rice in Brazil. / O objetivo desta dissertação foi analisar quantitativa e qualitativamente proteínas de reserva totais e as frações albumina, globulina, prolamina e glutelina presentes no grão de 29 genótipos de arroz silvestre Oryza glumaepatula e de 70 linhagens interespecíficas Retrocruzamento 2 desenvolvidas a partir do cruzamento O. sativa x O. glumaepatula. Destas linhagens, 34 (RC2F8) foram obtidas do cruzamento O. sativa BG90-2 x O. glumaepatula RS-16, e 36 (RC2F10) foram desenvolvidas a partir do cruzamento O. sativa CICA-8 x O. glumaepatula RS-16. Através da análise de variância para o teor de proteína total e frações protéicas, foram encontradas diferenças altamente significativas (P<0,01) entre os genótipos silvestres e entre as linhagens interespecíficas. O teor médio de proteína total dos genótipos silvestres foi de 12,17%, enquanto as linhagens do cruzamento BG90-2 x RS-16 apresentaram média de 7,05% e as linhagens do cruzamento CICA-8 x RS-16 apresentaram média de 8,40%. O genótipo silvestre BGA14280 destacou-se por apresentar o maior teor de proteína total (14,94%). Na análise comparativa envolvendo as linhagens interespecíficas e seus parentais, foram encontradas cinco linhagens com maior conteúdo de proteína total (teor médio de 10,95%), sendo significativamente superiores aos parentais cultivados BG 90-2 (10,0%) e CICA-8 (9,61%). No entanto, essas linhagens apresentaram teor inferior ao parental silvestre RS-16 (14,06%). Em relação às frações protéicas, 40 linhagens interespecíficas apresentaram valores mais elevados em relação aos seus parentais, exceto em uma ocasião, onde o parental silvestre RS-16 apresentou alto teor de glutelina. Entre os 29 genótipos silvestres, foram encontrados os maiores teores de albumina, prolamina e glutelina, exceto para a fração globulina, onde o genótipo silvestre BGA14162 não diferiu significativamente da cultivar BRS Bonança. A análise de SDS-PAGE da proteína total e da fração glutelina foi encontrada um perfil diferencial de &#945;-glutelinas entre os genótipos silvestres, com destaque para o genótipo BGA14232 que não apresentou &#945;-polipeptídeos comuns aos demais genótipos. Entre as linhagens interespecíficas e os seus parentais, foram encontrados perfis de proteína total e &#945;-glutelinas bastante similares, havendo diferença em relação a &#945;-glutelina de 40 kDa presentes apenas no parental silvestre RS-16, o que pode indicar uma constituição protéica diferencial em O. glumaepatula, já que a O. sativa apresentou &#945;-glutelinas de 39 kDa. Em relação às frações albumina, globulina e prolamina os genótipos silvestres apresentaram um perfil protéico diferenciado comparado às linhagens interespecíficas e o arroz cultivado, e a provável causa foram os dois cruzamentos em direção à BG90-2 e CICA-8, que foram os parentais recorrentes durante o desenvolvimento das linhagens interespecíficas. Os maiores teores de proteína encontrados para a espécie O. glumaepatula, os diferentes perfis protéicos e a identificação de linhagens interespecíficas com maior conteúdo protéico em relação aos parentais cultivados, deixam claro a contribuição favorável desta espécie para o melhoramento visando o aumento do valor nutricional do grão do arroz cultivado no Brasil.

No experimento I, objetivou-se avaliar os efeitos de aditivos microbianos e tempo de armazenamento na qualidade de silagens de milho. A cultura do milho foi ensilada sem aditivos (Controle) ou com inoculantes contendo bactérias láticas homofermentativas (Lactobacillus plantarum + Enterococcus faecium + Pediococcus acidilactici) + enzimas celulolíticas e hemiceluloliticas ou heterofermentativas (Lactobacillus buchneri) aplicados na dose 1 × 105 ufc/g. As silagens foram armazenadas em silos experimentais durante 3, 7, 15, 30, 60, 210, 390, 480 ou 570 dias. Foram avaliados: composição químico-bromatológica, produtos de fermentação, perfil microbiológico, perdas fermentativas, estabilidade aeróbia e degradabilidade ruminal in situ. Os inoculantes não afetaram a maior parte das variáveis estudadas. Entretanto, L. buchneri aumentou a concentração de ácido acético das silagens e diminuiu a deterioração aeróbia, confirmada pelo menor acúmulo térmico durante o ensaio de estabilidade aeróbia. O teor de carboidratos solúveis diminuiu ao longo do tempo de armazenamento, reflexo do metabolismo dos açúcares em produtos de fermentação. As concentrações da prolamina como esperado diminuíram e as concentrações de nitrogênio amoniacal e proteína solúvel aumentaram com os tempos de armazenagem prolongados, reflexo da ocorrência de proteólise na silagem de milho. O pH da silagem diminuiu rapidamente nos primeiros sete dias de armazenamentos mantendo-se estável para os demais tempos de estocagem, diferente do ocorrido para a concentração de ácido acético, que aumentou com o tempo de armazenamento. Verificou-se diminuição na contagem de bactérias láticas e leveduras ao longo do armazenamento. A produção de gás e a perda de matéria seca aumentaram com o tempo de armazenamento. O tempo de armazenamento aumentou todas as variáveis de EA. Os ganhos mais significativos para a EA se deram até aproximadamente 60 dias de armazenamento. A degradação ruminal de amido e, consequentemente de MS, foi incrementada ao longo do armazenamento. No experimento II, objetivou-se avaliar o desempenho de vacas leiteiras em função da estratégia de descarregamento da silagem de milho em silo do tipo trincheira: silagem de milho oriunda da metade superior do silo (topo) ou silagem de milho oriunda da metade inferior do silo (base). Foram utilizadas 24 vacas alocadas em 12 blocos casualisados, com arranjo de reversão simples com períodos de 21 dias. Os animais foram alojados em confinamento tie-stall. As dietas foram iso-protéicas (16,5%) e iso-amiláceas (17,0%), com 60% de silagem de milho (% MS). O consumo de matéria seca, produção e composição do leite foram determinados entre os dias 15 e 21 de cada período experimental. Apesar da silagem oriunda da base do silo levar à maior digestibilidade da dieta e menor concentração de nitrogênio ureico do leite (8,95 e 11,35 mg/dL) não houve efeito da dieta no consumo de matéria seca nem na produção de leite. Sob condições ótimas de manejo, a estratégia de descarregamento da silagem de milho não afeta o desempenho de vacas leiteiras. / In the experiment I, the aim was to evaluate the effects of microbial additives and length of storage on the quality of corn silage. Whole-corn plants were ensiled without or with inoculants containing homofermentative (Lactobacillus plantarum + Enterococcus faecium + Pediococcus acidilactici + cellulolytic and hemicellulolytic enzymes) or heterofermentative lactic acid bacteria (Lactobacillus buchneri) applied at 1 × 105 cfu/g. Treated forages were packed and stored in experimental silos for 3, 7, 15, 30, 60, 210, 390, 480, and 570 days. Samples were evaluated for chemical composition, fermentation end-products, microbial counts, fermentation losses, aerobic stability, and ruminal degradability in situ. Inoculants did not affect most of the variables studied. However, L. buchneri increased acetic acid concentration and decreased aerobic deterioration of silages, as indicated by the lower heat accumulation during the exposure to air. Soluble carbohydrates decreased across the storage period, reflecting the conversion of soluble sugars to fermentation end-products. Concentrations of prolamin decreased, whereas ammonia and soluble protein concentrations increased over the storage period, indicating the proteolysis. The silage pH declined rapidly in the first seven days of storage and remained stable for the remaining storage period, unlike for acetic acid concentration that increased with storage period. On the other hand, counts of lactic acid bacteria and yeasts decreased during the storage. Gas production and dry matter loss increased with the length of storage. The storage period increased all variables stability aerobic. Most of significant improvements in stability aerobic were observed during the first 60 days of storage. Ruminal degradability of starch and, consequently, dry matter increased along the storage. In the experiment II, the aim was to evaluate the influence of strategy of silage unload on the performance of dairy cows. Corn silage from a bunker silo was separated at unloading as silage from the upper half of the silo (top) or from the lower half of the silo (bottom) and used to compose total mixed rations fed to 24 lactating cows allocated in 12 randomized blocks, arranged in a cross-over design with 21 periods. Cows were housed in a tie-stall barn. All diets contained 60% of corn silage and were iso-nitrogen (16.5% CP) and iso-starch (17.0% of starch). Dry matter intake, milk yield and composition were determined from day 15 to 21 in each period. Although silage from bottom led to higher total tract DM digestibility and lower milk urea nitrogen concentration (8.95 vs. 11.35 mg/dL), most of evaluated variables were not affected by treatments. Under optimal silo management, the strategy used to unload corn silage does not affect the performance of dairy cows.