Previous research on grazing behavior has shown that ruminants will select a mixed diet. The use of adjacent monocultures is an essential tool for determining dietary preference of forages. Much of the work to date has been conducted with white clover (Trifolium repens L.) and perennial ryegrass (Lolium perenne L.). Partial preference for white clover over ryegrass has been reported consistently and partial preference for legumes is thought to occur regardless of the legume and grass species being evaluated. Two forage species, tall fescue (Festuca arundinacea Schreb. or Lolium arundinaceum (Schreb.) S.J. Darbyshire) and alfalfa (Medicago sativa subsp. sativa L.), which had not been evaluated together previously as adjacent monocultures were grazed by beef steers in the present set of experiments. Steers exhibited a partial preference for alfalfa of 61 to 65% when given a choice of grazing alfalfa or tall fescue as adjacent monocultures, regardless of the ground area proportion of the two forages offered. Steers grazing tall fescue monocultures spent more time ruminating (P = 0.02) and tended to graze less time (P = 0.06) than steers in adjacent monoculture treatments. Time spent idling, number of prehensions and mastications, and bite rate were similar (P > 0.05) among treatments. Steers grazing tall fescue monocultures spent less time standing, more time lying, were less active and took fewer steps (P ≤ 0.05) than steers in adjacent monoculture treatments. Grazing behavior was examined when alfalfa had not been in the previous diet of the steers. Cattle without previous experience grazing alfalfa spent 78% of the time grazing alfalfa, whereas after having experience grazing it they spent a lower (P = 0.04) proportion of their time grazing alfalfa (72%). Overall proportion of the day spent grazing both forages was lower (P = 0.0001) when alfalfa was novel (40%), compared to when steers were experienced grazing both forages (46%). Proportion of the day spent idling was greater (P < 0.0001) when alfalfa was novel (35%), compared to when both forages were familiar to the steers (26%). Previous research has reported that ruminants exhibit a diurnal pattern of preference by decreasing the proportion of white clover consumed from morning to late afternoon while increasing the proportion of perennial ryegrass in the diet. This is thought to be a strategy to increase fiber intake before nightfall or as a response to higher carbohydrate levels in grass in the afternoon. In the present study, proportion of grazing time in alfalfa was higher (P = 0.02) in the afternoon (76.8 %) than in the morning (72.1 %). While fiber concentration was higher in the tall fescue, carbohydrate concentrations were similar. Steers were not attempting to increase fiber intake in the afternoon in the present study. Dry matter intake of steers grazing adjacent monocultures of alfalfa and tall fescue was estimated with n-alkanes. Diet composition was estimated using n-alkanes and long chain alcohols (LCOH) in several different combinations. The use of LCOH added additional characterization of the forages, but diet composition estimates were not different (P ≥ 0.22) than when estimated using four different n-alkanes. Laboratory analysis costs may be reduced if n-alkanes alone can adequately characterize the forages being consumed, depending on the forage species in question. Meteorological conditions impacted DMI with intake being less in hotter conditions. Steers had similar partial preferences for alfalfa over tall fescue (P = 0.13, 79% and 70% alfalfa in yr 1 and 2, respectively) even though total DMI differed between years (P = 0.002, 9.4 kg d-1 and 4.5 kg d-1 in yr 1 and 2, respectively). Lower DMI in yr 2 was attributed to hotter air temperatures. When animals are consuming two different forages as adjacent monocultures such as in the current experiments, it is important to determine the proportion of each forage in the diet before calculating DMI using odd chain n-alkanes of the forage along with a dose even chained n-alkane. Dry matter intake can be overestimated if the proportion of the forages consumed is not estimated and accounted for in the equation. This would apply to other studies utilizing mixed swards or any diet containing multiple components that differ in concentration of the n-alkane being used for DMI estimation. Analysis of n-alkane concentration should be performed on each item in the diet and the proportion of each item in the diet estimated so that the right value can be used in the calculation. Differences in marker concentrations between years also indicate the importance of analyzing those concentrations in the feed or forage at the time of fecal collection and not using values reported from previous research. / Ph. D.

Determining intake of feeds in horses is an important factor in incorporating supplements in their diets. Fecal recoveries (R), fecal output (FO), dry matter digestibility (DMD) and dry matter intake (DMI) were estimated using alkanes as markers in 8 thoroughbred geldings. The experiment compared two diets in a 2 X 2 latin square experiment. The diets were mixed grass hay only (H) and the same hay plus a cereal by-product (H + CBP). The cereal by-product (CBP) was the high fat component added to feeds at Virginia Tech's Middleburg Agricultural Research and Extension Center. The apparent digestibility of ether extract (EE) and other nutrients in the H and H + CBP, as well as the partial digestibility of CBP were also determined. The periods were 21 d each with a dietary accommodation period followed by eight days of dosing the even chain alkanes dotriacontaine (C32) and hexatriacontane (C36) as external markers. Total collection (TC) was performed the last 4 d of dosing. The results show that mean recoveries of alkanes were close to 100%, but the range for individual alkanes was wide, and the pattern of recoveries for alkanes of different chain length was inconsistent from feed to feed. The results also indicate that mean estimates of the DMI, DMD and FO of a feed, such as H or H + CBP, are determined with reasonable accuracy by means of alkane markers. In contrast, alkane estimates of DMI and DMD in an individual horse fail to predict corresponding TC estimates. The alkane estimate of FO in an individual horse predicts a TC value with error of 16.4%. The CBP was found to be an excellent source of EE, CP and fiber but a poor source of Ca. / Master of Science

The aim of this thesis was to determine the effect of row spacing on sorghum yields and dry matter. The trial was established on 29 May 2015 on land belonging to the Agricultural Cooperative Milevsko, which is situated in the corn-growing area. The trial compared four varieties of sorghum, namely Aristos, Goliath, KWS Freya and KWS Sole. The varieties were sown in different row spacings, namely 75 cm, 60 cm, 45 cm a 30 cm. The samples taken on three dates were analysed for dry matter content. Each variety showed a gradual increase in the dry matter content. During the harvest on 5 October 2015 the varieties KWS Freya and KWS Sole reached an optimal value of the dry matter when planted in all spacings. All varieties produced the highest average yield of green matter when planted in rows spaced 60 cm apart. The variety Aristos produced the highest average yield of green matter. The KWS Sole variety reached the lowest average yield of green matter when planted in rows 76 cm apart. All varieties with 60 cm row spacings, except for KWS Sole, produced the highest average yield of dry matter. The highest average yield of dry matter was reached by Aristos and the lowest by KWS Sole. The results of the one-year trial did not prove a direct connection of the effect of row spacing on dry matter. The effect of row spacing on green and dry matter yield was proved. The optimum row spacing seems to be 60 cm.

Resumo: O experimento foi conduzido na UNESP - Campus de Botucatu, Faculdade de Medicina Veterinária e Zootecnia. O delineamento experimental foi em blocos ao acaso num arranjo fatorial com três cultivares de Brachiaria brizantha (Marandu, Xaraés e BRS Piatã) e duas alturas de resíduo (15 e 25 cm), no total de seis tratamentos com quatro repetições (parcelas de 20 m2). O período de avaliação foi de um ano (01/12/2007 a 10/12/2008), com a realização de oito cortes, sendo três na primavera, três no verão, um no outono e um no inverno. A produção de massa seca (MS) da Xaraés foi maior no verão e na primavera em relação à Marandu. No somatório do ano a produtividade de MS da Xaraés foi 27,07% superior à Marandu, alcançando valor elevado (20.023 kg/ha), o que demonstra o potencial de utilização deste genótipo, principalmente em sistemas de produção de bovinos de corte mais intensivos. A produção de MS da Piatã nas estações do ano foi semelhante à Marandu, totalizando 17.572 e 15.757 kg/ha, respectivamente. Os dados de produção indicam que a Piatã apresentou a melhor distribuição da forragem produzida ao longo do ano. A produção de forragem das cultivares foi maior na altura do resíduo de 15 cm no verão e inverno, e não diferiu nas alturas de manejo no outono e primavera, demonstrando exigências diferentes de manejo do capim ao longo do ano. Os resultados obtidos confirmam a recomendação e a importância da cultivar Piatã como alternativa de utilização e diversificação das pastagens nos sistemas produtivos. / Abstract: The experiment was conducted in the School of Veterinary Medicine and Animal Science of UNESP - Botucatu Campus. The experimental design was a complete randomized blocks in a factorial arrangement with three cultivars of Brachiaria brizantha (Marandu, Xaraés and BRS Piatã) and two stubble heights (15 and 25 cm), in the total six treatments with four replications (20 m² plots). The evaluation period was of one year (12/01/2007 to 12/10/2008) with eight cuts: three in the spring, three in the summer, one in the fall and one in the winter. The production of dry matter (DM) of Xaraés in summer and spring were higher than Marandu with a total of 27.07% higher DM than Marandu. The total DM production was 20,023 kg/ha, demonstrating the potential of use of the Xaraés cultivar, especially in more intensive systems of beef cattle production. DM production of Piatã in the seasons was similar to Marandu, totalizing 17,572 and 15,757 kg/ha, respectively. The production data indicate that Piatã cultivar had the best distribution of forage produced during the year. The forage production of cultivars was higher in the stubble height of 15 cm in summer and winter, and did not differ for two heights of management in the fall and spring, showing different requirements of grass management during the year. The results confirm the recommendation and the importance of Piatã cultivar as an alternative of use and diversification of pastures in the production systems. / Orientador: Ciniro Costa / Coorientador: Paulo Roberto de Lima Meirelles / Banca: Heraldo César Gonçalves / Banca: Roberto Antonio Rodella / Banca: Cacilda Borges do Valle / Banca: Valdo Rodrigues Hering / Doutor

O experimento foi conduzido na FZEA/USP, Pirassununga, de julho de 1998 a junho de 2000, com objetivo de descrever os efeitos de intensidades de pastejo e de períodos de ocupação da pastagem na massa de forragem, perdas e valor nutritivo do capim-Mombaça. Foram estudados os efeitos de três intensidades de pastejo, representadas por três ofertas de forragem: baixa = (4%) - 4kg de matéria seca verde (MSV) para cada 100kg de peso animal em pastejo por dia; média = (8%) e alta = (12%) e dois períodos de ocupação dos piquetes, um e três dias. A área experimental constituía-se de 24 piquetes de 400 m2 cada (20 x 20 metros), divididos em quatro blocos de seis piquetes cada. Foram considerados dois períodos experimentais: época das águas (verão agrostológico), quando foram realizados quatro pastejos, com período de descanso de 35 dias e época da seca (inverno agrostológico), sendo realizados dois pastejos, com período de descanso de 70 dias. O delineamento experimental foi em blocos completos ao acaso, com um arranjo fatorial 3 X 2 para tratamentos (3 ofertas x 2 períodos de ocupação), em parcelas subdivididas no tempo (pastejos), com 4 repetições. No verão, a produção de matéria seca verde do capim-Mombaça foi maior quando se fez o manejo mais leniente da pastagem, porém utilizando-se de menor período de permanência dos animais em pastejo. No verão e inverno, a relação F/H foi maior para o pastejo mais intenso e período de ocupação, condicionada por pastejo não seletivo e de maior consumo, perdas ou menor produção de hastes. No decorrer dos pastejos, o menor tempo de permanência nos piquetes condicionou a menor participação de lâminas foliares. A quantidade de material senescente do pré-pastejo foi maior quando se utilizou o pastejo mais leniente em associação com o menor período de permanência na pastagem durante o verão. Mesmo assim, a produção líquida de material verde foi maior. No inverno, apesar do material senescente ter sido crescente nas ofertas, a permanência de 3 dias, em pastejo mais intenso (4%), condicionou uma menor quantidade de material senescente. As condições climáticas foram determinantes no processo produtivo da planta forrageira, condicionando o balanço entre produção e perdas por senescência. Quando o pastejo foi mais leniente, a quantidade de matéria seca verde residual foi alta, mas independe do tempo de permanência. No entanto, quando se realizou o pastejo drástico, o menor tempo de permanência condicionou maior resíduo, porém com maiores perdas de matéria seca no chão. No verão e no inverno, o menor tempo de permanência dos animais nos piquetes condicionou as maiores perdas de matéria seca na planta pós pastejo. No entanto, essa foi compensada pela maior quantidade de matéria seca verde residual. As ofertas de forragem de 4% e 8%, no verão, e de 8% e 12%, no inverno, favoreceram maior consumo aparente de matéria seca. O mesmo comportamento foi observado para 3 dias de ocupação nas duas estações. No pastejo mais leniente, apesar de favorecer a seletividade, a planta apresentou folhas de menor teor protéico, nas duas estações. No entanto, o menor tempo de permanência nos piquetes, no verão, e o maior tempo, no inverno, num pastejo mais intenso, permitiram aos animais consumir uma lâmina foliar mais protéica e com menor teor de parede celular. No final do verão, o período de ocupação de 1 dia ou as ofertas de 4% e 8% apresentaram maiores teores protéicos. Por outro lado, os teores de fibra em detergente neutro e ácido oscilaram, mas permaneceram menores na oferta de 4%, no verão e no inverno. A relação inversamente proporcional entre os teores protéicos e de parede celular, com a diminuição da intensidade de pastejo, nas duas estações, condicionou a degradabilidade da matéria seca. Os baixos teores protéicos e os altos teores de parede celular, do resíduo, condicionaram o momento de retirada dos animais da pastagem, sendo mais crítico no inverno, devido sua quantidade e valor nutritivo. / This trial was conducted between July 1998 and June 2000 aiming at evaluating the effects of grazing intensity and grazing periods on mass of herbage, losses and nutritional value of Mombaçagrass. Treatments were comprised of combinations between three grazing pressures, represented by three levels of herbage allowance: low (4%); medium (8%) and high (12%), equivalent to 4, 8 and 12 kg of green dry matter/100 kg of body weight/day, and two grazing periods: one or three days. The experimental area was divided up into 24 400m2 paddocks (20 x 20m2), splitted into 4 blocks with 6 paddocks each. Grazing during "summer" were performed according to a 35-day rest period (4 grazings); and during "winter" according to a 70-day rest period (2 grazings). The experimental design was a complete randomized block in a 3 x 2 factorial arrangement, replicated four times. In "summer", Mombaçagrass dry matter yield was higher with lower grazing intensity and fewer days of animal grazing. The leaf/stem ratio was higher for hard grazings with longer grazing periods, since animals were not selective or either loss or less stem production was observed. Leaf lamina proportion decreased with grazing duration of 1 day in relation to 3 days. During "summer", the association between lower grazing intensity and short grazing period resulted in higher quantity of senescent material for the next period. However, net dry matter production was higher under those circumstances. In "winter", a three-day grazing period associated with intensive grazing (4%) resulted in a lower proportion of senescent material. Climatic conditions were important in the forage production system, providing the equilibrium between production and senescence losses. When grazing intensity is lower, amount of residual dry matter is higher, however it is independent of grazing period. However under high grazing intensity, shorter time of grazing lead to higher residual dry matter, but with larger losses of material on soil. During both "summer" and "winter", the shorter period of grazing, the higher the losses of dry matter after grazing period, although plants still kept more residual green tissues after grazing. Herbage allowances of 4 and 8 % ("summer") and 8 and 12% ("winter"), resulted in a bigger apparent dry matter consumption. The same result was observed for the 3 – day grazing period for both seasons. Lenient grazing, although favoring animal selectivity, resulted in plants with lower leaf protein content during both seasons. However, short grazing period during "summer" and long grazing period during "winter", when associated with hard grazing (4%), resulted in leaf tissues containing more protein with lower cell wall content. By the end of "summer", paddocks grazed for 1 day or at 4 or 8% of herbage allowance, showed higher leaf protein content. On the other hand, although neutral and acid detergent fiber content was somewhat variable, they were lower at low herbage allowance (4%), both in "summer" and "winter". The negative relationship between protein and cell wall content, when grazing intensity was reduced increasing herbage allowances, in both seasons, resulted in lower herbage dry matter degradability, lower protein and higher cell wall content in the residual forage at the time animals were removed from the paddocks. This was particularly critical in "winter", when residual herbage exhibited the lowest nutritive value.

Submitted by Marcos Anselmo (marcos.anselmo@unipampa.edu.br) on 2017-06-12T13:44:14Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) OTÁVIO BACKES MEOTTI.pdf: 806223 bytes, checksum: d35606330f21e0cb45f98cc7474c455a (MD5) / Approved for entry into archive by Marcos Anselmo (marcos.anselmo@unipampa.edu.br) on 2017-06-12T13:44:34Z (GMT) No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) OTÁVIO BACKES MEOTTI.pdf: 806223 bytes, checksum: d35606330f21e0cb45f98cc7474c455a (MD5) / Made available in DSpace on 2017-06-12T13:44:34Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) OTÁVIO BACKES MEOTTI.pdf: 806223 bytes, checksum: d35606330f21e0cb45f98cc7474c455a (MD5) Previous issue date: 2017-03 / O período de transição é uma fase crítica na vida produtiva das vacas leiteiras, devido ao aumento do seu requerimento nutricional, concomitante a uma redução fisiológica na ingestão de matéria seca, e comprometimento imune. Devido a estes fatores, este período se associa a um estado catabólico, com alta incidência de enfermidades metabólico-nutricionais e infecciosas, que levam a perdas econômicas e deterioro do bem-estar animal. Como muitas dessas enfermidades são antecedidas por uma diminuição na ingestão de matéria seca (IMS), a avaliação de indicadores relacionados ao consumo poderiam servir para predizer o risco de doenças, durante o período de transição. Como o escore de enchimento ruminal (EER) apresenta uma boa correlação com IMS a presente dissertação teve dois objetivos: 1- correlacionar e comparar os escores de enchimento ruminal (EER, 1 a 5) com indicadores sanguíneos do balanço energético e mineral. 2- validar o escore de enchimento ruminal como ferramenta de monitoramento de saúde e taxa de retorno a ciclicidade em vacas leiteiras no período pré-parto. Para responder aos objetivos realizou-se um estudo de coorte com 113 vacas multíparas Holstein, e os resultados de cada objetivo são apresentados em 2 artigos separados. Para responder ao objetivo 1 foram coletados semanalmente nas semanas -2,-1, parto, +1,+2,+3, uma amostra de sangue para analisar as concentrações de βOH-butirato (BHBA), ácidos graxos não esterificados (NEFA), colesterol e cálcio, e aferido simultaneamente o EER e escore de condição corporal (ECC) das vacas. Nesse estudo comprovou-se que o EER correlacionou-se principalmente com o ECC. Também, se observou que o EER associou-se com indicadores sanguíneos estudados tanto no período pré como pós-parto, sendo que vacas com maiores EER (EER3) apresentaram maiores concentrações de cálcio, BHBA e colesterol no pré-parto. Já, no pós-parto vacas com EER1 tiveram valores maiores de NEFA e menores de colesterol que vacas com EER3. Para responder ao objetivo 2 mensurou-se o EER nas semanas -2, -1 e parto, diagnosticou-se a ocorrência de doenças clínicas e avaliou-se o regresso a ciclicidade entre a 4º e 8º semana pós-parto. Determinou-se o EER como preditor das doenças mais prevalentes (metrite, mastite, retenção placentária, deslocamento de abomaso e afecções podais). Observou-se que o EER≤2 duas semanas antes do parto foi um bom preditor de todas as doenças acima descritas, com sensibilidade variando de 53% a 75% e especificidade de 80%. Por outro lado, vacas com EER1 durante o pré-parto e parto voltaram mais tardiamente a ciclicidade e em menor porcentagem quando comparadas com vaca com EER3. Portanto o escore de enchimento ruminal correlacionou-se com os indicadores sanguíneos durante período de transição, bem como serviu como preditor para as doenças do período de transição e regresso a ciclicidade, podendo ser utilizado como ferramenta de monitoramento da saúde de vacas leiterias multíparas. / The transition period is a critical phase in the productive lives of dairy cows, due to the increase in their nutritional requirement, concomitant with a physiological reduction in dry matter intake, and immune compromise. Due to these factors, this period is associated with a catabolic state, with a high incidence of metabolic-nutritional and infectious diseases, leading to economic losses and deterioration of animal welfare. Since many of these diseases are preceded by a decrease in dry matter intake (DMI), the evaluation of consumption indicators could serve to predict disease risk during the transitional period. As the rumen fill score (RFS) presents a good correlation with DMI, the present dissertation had two objectives: 1 – To correlate and compare rumen fill (RFS, 1 to 5) with blood indicators of negative energy balance. 2 – To validate the rumen fill score as a health monitoring tool and rate of return to cyclicality when it comes to dairy cows’ pre-calving. In order to answer the objectives, a cohort study was carried out with 113 Holstein multiparous cows, and the results of each objective are presented in 2 separate articles. To respond to objective 1 blood samples were collected to analyze the concentrations of βOH-butyrate (BHBA), non-esterified fatty acids (NEFA), cholesterol and calcium at week -2, -1, calving, + 1, + 2, +3, and simultaneously, RFS and cow’s body condition score (BCS) were measured. It was verified in this study that the RFS is correlated mainly with the BCS. Also, it was observed that the RFS was associated with blood indicators studied in pre and post partum periods, and cows with higher RFS (RFS 3) had higher concentrations of calcium, BHBA and cholesterol in prepartum. In the postpartum period, cows with RFS 1 had higher NEFA values and lower cholesterol than cows with RFS 3. To respond to objective 2, the RFS was measured at week -2, -1 and calving, clinical diseases were diagnosed and the return to cyclicity between the 4th and 8th week postpartum was evaluated. RFS was determined as a predictor of the most prevalent diseases (metritis, mastitis, placental retention, displaced abomasum and lameness). It was observed that EER≤2 two weeks before calving was a good predictor of all diseases described above, with sensitivity varying from 53% to 75% and specificity of 80%. On the other hand, cows with EER1 during prepartum and calving returned to cyclicity later and in a lower percentage when compared to cows with EER3. Therefore, the ruminal filling score correlated with the blood indicators during the transitional period, and served as a predictor for the diseases of the transition period and return to cyclicity. It can be used as a monitoring tool for the health of multiparous dairy cows.

O pastejo é considerado um fator determinante para a manutenção e conservação da vegetação campestre (campos) no sul do Brasil, sendo considerado o responsável por construir a heterogeneidade estrutural, a composição de espécies e a diversidade dos campos. Porém o manejo do pastejo é fundamental para sucesso da atividade pecuária, uma vez que longos períodos de pastejo excessivo e intenso ao invés de manter áreas campestres pode degradá-las, diminuindo a diversidade e produtividade, tornando os campos suscetíveis a invasão por espécies exóticas. Para o sucesso da relação construída entre o manejador, os animais e a vegetação, as estratégias de manejo que possibilitem uma pecuária rentável, mas que busque conservar a vegetação campestre, são fundamentais. O objetivo desta tese foi verificar os efeitos do pastejo sobre a vegetação campestre, tendo como ferramenta principal para isso, diferentes manejos. Os efeitos do pastejo foram avaliados através de índices de diversidade taxonômica e funcional, e da variação de atributos funcionais de gramíneas, analisando especificamente: (1) como estratégias de manejo contínuo e rotativo influenciam a dinâmica da vegetação campestre (biomassa, diversidade, riqueza e equitabilidade); (2) a influência do manejo do pastejo na composição e diversidade funcional de comunidades campestres descritas por gramíneas, e os efeitos sobre a variação intra- e interespecífica de atributos foliares (SLA e LDMC) das espécies de gramíneas; (3) o efeito de diferentes intensidades de pastejo (ofertas de forragem) nas diversidades alfa e beta das comunidades de plantas. Foram verificadas mudanças na diversidade, equitabilidade, riqueza de espécies, biomassa condicionadas pelo pastejo rotativo, que se mostrou benéfico para vegetação campestre. O pastejo rotativo proporcionou também um incremento na diversidade funcional, condicionado pela variação intra- e interespecífica nos atributos das gramíneas. Diferentes intensidades de pastejo promoveram diferenças de alfa e beta diversidade sob diferentes intensidades de pastejo. O pastejo demonstrou exercer papel determinante em toda a dinâmica campestre, tendo efeitos consideráveis em todos os níveis de avaliação, desde a riqueza de espécies até na diversidade funcional, ficando evidente que a decisão do manejo é fundamental tanto para a produtividade quanto para a manutenção da vegetação campestre. / Grazing is considered a determining factor for the maintenance and conservation of grasslands in southern Brazil and is considered one of the main driver of the structural heterogeneity, species composition and diversity of the grasslands. But the management of grazing is key to the success of livestock farming, since long periods of excessive and intense grazing instead of maintaining grassland, can degrade them, reducing the diversity and productivity, leading the grassland susceptible to invasion of exotic species. For the success of the relationship built between managers, animals and vegetation, a strategic management that allows an efficient farming together with the conservation of grassland vegetation is essential. The objective of this thesis was to investigate the effects of grazing on the grassland, based on different managements of grazing. The effects of grazing were evaluated by taxonomic and functional diversity indices, and the variation of functional traits of grasses, analyzing specifically: (1) how continuous and rotational grazing management influence the dynamics of grassland vegetation (biomass, diversity, richness and evenness); (2) the influence of grazing management on the functional composition and functional diversity in grassland communities described by grasses, and its effects on the intra- and interspecific variation of leaf traits (SLA and LDMC) of grass species; (3) the effect of different grazing intensities (forage dry matter offer) in the alpha and beta diversity of plant communities. Changes in diversity, evenness, species richness, and biomass were verified, which were conditioned by the rotational grazing that proved beneficial to grassland. The rotational grazing provided also an increase in functional diversity, due to intra and interspecific variation of the grasses traits. Different grazing intensities promoted differences in alpha and beta diversity under different grazing intensities. Grazing demonstrated to have a decisive role in the whole dynamics of grassland communities, with considerable effects on all levels here assessed, from the species richness to the functional diversity, becoming apparent that the management decision is very important for both the productivity and the maintenance of grassland structure and diversity.

<p>Prinos zrna predstavlja jednu od najznačajnijih i najsloženijih osobina u oplemenjivanju biljaka. Poznavanje razvića, rastenja i akumulacije suve materije, omogućava pravilan odabir genotipova i odgovarajuće tehnologije gajenja. Cilj istraživanja je bio da se izvr&scaron;i ispitivanje filohrona, akumulacije i translokacije suve materije nadzemnog dela biljaka, prinosa zrna i komponenti prinosa, različitih genotipova ozime p&scaron;enice i ječma sejanih u vi&scaron;e rokova setve i vegetacionih sezona. Zatim da se utvrdi odgovarajuća jednačina koja opisuje akumulaciju suve materije i pojavu listova na glavnom stablu ječma i p&scaron;enice u funkciji sume temperatura tokom različitih rokova setve i vegetacionih sezona. U ogled je bilo uključeno po &scaron;est genotipova ozimog dvoredog ječma i ozime p&scaron;enice različitog porekla, pedigrea i agronomskih osobina, sejanih dve sezone u četiri roka setve. Sredinom cvetanja i u punoj zrelosti, uzeto je 10 slučajno odabranih biljaka. Na uzetim biljkama određena je masa pojedinačnih organa i komponente prinosa, kao i translokacija suve materije i doprinos asimilata akumuliranih pre cvetanja u masi zrna. Za utvrđivanje filohrona i ukupnog broja listova, dva puta nedeljno se očitavao broj listova na obeleženim biljkama tokom čitave sezone. Istovremeno se uzimao i uzorak od pet biljaka u cilju praćenja akumulacije suve materije. Sezona, rok setve i sorta su imali značajan uticaj na variranje ukupnog broja listova i filohrona kod ječma i p&scaron;enice. U proseku, sorte ječma su formirale vi&scaron;e listova u odnosu na p&scaron;enicu, dok se p&scaron;enica karakteri&scaron;e dužim filohronom. Kasnija setva dovela je do značajnog smanjenja broja listova i skraćenja filohrona kod obe vrste. U zavisnosti od sezone, roka setve, sorte i njihove interakcije menjala se i biomasa biljaka u cvetanju i prinos zrna. Translokacija suve materije je bila u pozitivnoj korelaciji sa biomasom biljaka u cvetanju. Akumulacija biomase nadzemnog dela biljaka tokom sezone, pratila je tipičan sigmoidni obrazac u svim kombinacijama rokova setve i sorti. Od tri posmatrane nelinearne jednačine, Logistička jednačina se pokazala najprikladnijom za opisivanje akumulacije suve<br />materije tokom sezone kod ječma i p&scaron;enice. Rezultati istraživanja ukazuju na značaj vegetativne mase biljaka u cvetanju, koja predstavlja bitan izvor asimilata za translokaciju u zrno. Ovi rezultati ukazuju da je tokom oplemenjivanja strnih žita, neophodno stvarati genotipove sa većim brojem listova koji bolje nakupljaju biomasu, odnosno genotipove koji će u optimalnom roku setve, imati usklađen fenolo&scaron;ki razvoj sa agroekolo&scaron;kim uslovima u području Panonske nizije.</p> / <p>Grain yield is one of the most important and complex traits in plant breeding. Knowledge about crop development, growth and dry matter accumulation enables the appropriate selection of genotypes and field technology. The aims of this study were to investigate the variability of phyllochron, dry matter accumulation and translocation, grain yield and yield components of various wheat and barley genotypes, in relation to the sowing date and growing season. Furthermore, the goal was to find the equation that would appropriately describe dry matter accumulation and leaf appearance of wheat and barley. Six winter barley and six winter wheat genotypes, characterized by different origin, pedigree and agronomic traits, were sown in two growing seasons across four sowing dates. At the anthesis and physiological maturity, 10 randomly selected plants were manually cut at ground level. Dry mass of different plant organs, yield components, dry matter translocation and contribution of pre-heading dry matter to grain yield were determined. To determine the leaf number and phyllochron, measuring was done according to the Haun scale on three tagged plants per replication three times per week. Also, samples consisting of five plants were collected to determine dry matter accumulation. Growing season, sowing date and variety had significant influence on the final leaf number and phyllochron of wheat and barley. At average, barley varieties had more leaf compared to wheat, while wheat had higher phyllochron values. Late sowing reduced the final leaf number and phyllochron in both barley and wheat. Furthermore, growing season, sowing date, variety and sowing date &times; variety interaction had significant influence on crop biomass at anthesis and grain yield. Dry matter translocation was in positive correlation with dry matter content at anthesis. Dry matter accumulation across growing seasons had a typical sigmoid pattern in every combination of sowing date and variety. Among studied models, the logistic equation was the most appropriate for description of dry matter accumulation in wheat and barley. Results from this study highlight the importance of dry matter content at anthesis, which represent a significant source of assimilates for translocation into the grain. These results indicated that during the selection of small grain cereals, it is necessary to develop genotypes characterized by higher leaf number and increased biomass, i.e. genotypes that in optimal sowing dates, have an adjusted phenological development to the agro-ecological conditions of the Panonian plane.</p>

Submitted by Cláudia Bueno (claudiamoura18@gmail.com) on 2016-03-10T18:09:47Z No. of bitstreams: 2 Dissertação - Diogo Silva Santos - 2015.pdf: 1506630 bytes, checksum: ad4d5cea1bf639548aa84a33111e32a7 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-03-14T14:20:43Z (GMT) No. of bitstreams: 2 Dissertação - Diogo Silva Santos - 2015.pdf: 1506630 bytes, checksum: ad4d5cea1bf639548aa84a33111e32a7 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-03-14T14:20:43Z (GMT). No. of bitstreams: 2 Dissertação - Diogo Silva Santos - 2015.pdf: 1506630 bytes, checksum: ad4d5cea1bf639548aa84a33111e32a7 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-10-20 / We evaluated the effects of adding soybean meal (SM) as an additive sequestrant of moisture and nutrient source in mombasa grass silage, compared to standard fermentation and in situ degradability of silage with different levels of inclusion of soybean meal. The experiment was conducted at Fazenda AJR, in the municipality of Goiás, Goiás.The treatments used were composed of four levels of inclusion of SM 0%, 10%, 15% and 20%.The experimental design was completely randomized, with four treatments and four replicates.The mombasa grass featured 24.8% DM cutting time and was silage in silos, PVC minis closed during 65 days.After the opening of the minis silos were performed to determine the losses weighing through the quantification of effluent production and losses by gas.Samples were collected for further analysis of ammoniacal nitrogen, pH and soluble carbohydrates, as well as the chemical composition-mycotoxin (s), degradability in situ.The addition of the additive has increased the level of DM and was efficient in the control of effluents and gaseous losses.The additive allowed great recovery rates of DM.The addition of SM favored the increase of lactic, acetic acid and butyric acid and propionic concentrations, reflecting the improvement of the fermentation of silage profile.The addition of the SM has provided greater total carbohydrates content in all levels of inclusion.Silages containing SM had highercrude protein (CP) content, as well as lower fiber content in a neutral detergent (NDF) and acid detergent fiber (ADF).The degradability of the DM, NDF and CP improved linearly according to the addition of SM, reaching degradabilities potential and specific degradabilities best, with the inclusion of 20% of SM.The addition of soybean meal provided silage well preserved, with minimal loss of DM and still contributed significantly to the improvement of the nutritional value of silage. / Foram avaliados os efeitos da adição de farelo de soja (FS) como aditivo sequestrante de umidade e fonte de nutrientes na ensilagem de capim-mombaça, em relação ao padrão fermentativo e a degradabilidade in situ das silagens com diferentes níveis de inclusão de farelo de soja.. O experimento foi conduzido na Fazenda AJR, no município de Goiás, GO. Os tratamentos utilizados foram constituídos por quatro níveis de inclusão de FS 0%, 10%, 15% e 20%. Utilizou-se o delineamento experimental inteiramente ao acaso, com quatro tratamentos e quatro repetições. O capim-mombaça apresentava 24,8% de MSno momento do corte e foi ensilado em mini silos de PVC, permanecendo fechados durante 65 dias. Após a abertura dos mini silos foram realizadas pesagens para a determinação das perdas através da quantificação da produção por efluentes e das perdas por gases. Amostras foram coletadas para posteriores análises de nitrogênio amoniacal, pH e carboidratos solúveis, bem como a composição químicobromatológica, degradabilidade in situ. A adição do aditivo aumentou o teor de MS e foi eficiente no controle de perdas por efluentes e gases. O aditivo permitiu ótimos índices de recuperação de MS. A adição de FS favoreceu o aumentodas concentrações de ácido lático, acético e butírico e diminuindo as concentrações de propiônico, refletindo na melhoria do perfil fermentativo das silagens. A adição do FS proporcionou maior teor de carboidratos totais, em todos os níveis de inclusão. As silagens contendo FS apresentaram maior teor de proteína bruta (PB), além de menor teor de fibra em detergente neutro (FDN) e fibra em detergente ácido (FDA). A degradabilidade da MS, FDN e PB melhorou linearmente de acordo com a adição de FS, atingindo melhores degradabilidades potenciais e degradabilidades especificas, com a inclusão de 20% de FS. A adição de farelo de soja proporcionou silagens bem conservadas, com mínimas perdas de MS e ainda contribuiu de forma significativa para a melhoria do valor nutritivo das silagens.

Submitted by Cesar Gonçalves (ciacmdo12rm@gmail.com) on 2018-10-26T16:05:44Z No. of bitstreams: 3 Dissertação Final.pdf: 650833 bytes, checksum: c039259c30bfaf2e20c7885572ec4ec6 (MD5) CartaEncaminhamentoAutodepósito.doc: 173056 bytes, checksum: 9de5d089494c995b9a6da3b71bf48fa1 (MD5) IMG_20181026_115234694.jpg: 3530000 bytes, checksum: 25800ea2f43f0350fa14e734c2a8af5b (MD5) / Rejected by PPGCAN Ciência Animal (ppgcan.ufam@gmail.com), reason: Arquivo da dissertação incorreta. on 2018-11-06T20:21:00Z (GMT) / Submitted by Cesar Gonçalves (ciacmdo12rm@gmail.com) on 2018-11-06T20:48:07Z No. of bitstreams: 4 CartaEncaminhamentoAutodepósito.doc: 173056 bytes, checksum: 9de5d089494c995b9a6da3b71bf48fa1 (MD5) IMG_20181026_115234694.jpg: 3530000 bytes, checksum: 25800ea2f43f0350fa14e734c2a8af5b (MD5) Dissertação Cesar Gonçalves (PPGCAN).pdf: 787143 bytes, checksum: 72fd2ab6ff5755336d1f5f7843426426 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by PPGCAN Ciência Animal (ppgcan.ufam@gmail.com) on 2018-11-06T20:49:12Z (GMT) No. of bitstreams: 4 CartaEncaminhamentoAutodepósito.doc: 173056 bytes, checksum: 9de5d089494c995b9a6da3b71bf48fa1 (MD5) IMG_20181026_115234694.jpg: 3530000 bytes, checksum: 25800ea2f43f0350fa14e734c2a8af5b (MD5) Dissertação Cesar Gonçalves (PPGCAN).pdf: 787143 bytes, checksum: 72fd2ab6ff5755336d1f5f7843426426 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2018-11-07T12:34:45Z (GMT) No. of bitstreams: 4 CartaEncaminhamentoAutodepósito.doc: 173056 bytes, checksum: 9de5d089494c995b9a6da3b71bf48fa1 (MD5) IMG_20181026_115234694.jpg: 3530000 bytes, checksum: 25800ea2f43f0350fa14e734c2a8af5b (MD5) Dissertação Cesar Gonçalves (PPGCAN).pdf: 787143 bytes, checksum: 72fd2ab6ff5755336d1f5f7843426426 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-11-07T12:34:45Z (GMT). No. of bitstreams: 4 CartaEncaminhamentoAutodepósito.doc: 173056 bytes, checksum: 9de5d089494c995b9a6da3b71bf48fa1 (MD5) IMG_20181026_115234694.jpg: 3530000 bytes, checksum: 25800ea2f43f0350fa14e734c2a8af5b (MD5) Dissertação Cesar Gonçalves (PPGCAN).pdf: 787143 bytes, checksum: 72fd2ab6ff5755336d1f5f7843426426 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-09-14 / The objective of this study was to characterize the apparent digestibility of feeds containing increasing levels of crude protein in the feed of matrinxã. The experimental units consisted of groups with 10 matrinxã juveniles, totaling 120 fish, with three replicates per treatment. The collected data were submitted to polynomial regression analysis at 5% significance. They were observed in the dry matter digestibility, with an increase in nutrient utilization from the increase of the protein level in the rations. This behavior was directly reflected in the digestibility of the other nutrients by matrinxã juveniles, such as ash, crude protein, apparent digestible energy, apparent digestible energy digestibility and energy: protein ratio. However, this behavior was not observed in the digestibility of the ethereal extract. The digestibility of nitrogen, phosphorus, calcium, magnesium, copper and zinc showed positive linear behavior, increasing its utilization from the increase of the protein level in the rations. However, the digestibility of potassium, iron and manganese reduced from the increase of the level of protein in the rations. The present study indicated that the increase of the protein level in feeds for juveniles of matrinxã improved nutrient digestibility. Our results indicated that 40% crude protein in the diets presented better results. However, the exacerbated increase in protein levels, and consequently nitrogen, in rations can cause metabolic imbalances, weakening the absorption and utilization of some nutrients, such as microminerals. / O objetivo deste estudo foi caracterizar a digestibilidade aparente de rações contento níveis crescentes de proteína bruta na alimentação de matrinxã. As unidades experimentais consistiam de grupos com 10 juvenis de matrinxã, totalizando 120 peixes, com três repetições por tratamento. Os dados coletados foram submetidos à análise de regressão polinomial a 5% de significância. Foram observadas na digestibilidade da matéria seca, com aumento no aproveitamento de nutrientes a partir do aumento do nível de proteína nas rações. Esse comportamento refletiu-se diretamente na digestibilidade dos demais nutrientes pelos juvenis de matrinxã, tais como cinzas, proteína bruta, energia aparente digestível, digestibilidade da energia digestível aparente e relação energia:proteína. Entretanto, este comportamento não foi observado na digestibilidade do extrato etéreo. A digestibilidade do nitrogênio, fósforo, cálcio, magnésio, cobre e zinco mostrou comportamento linear positivo, aumentando seu aproveitamento a partir do aumento do nível de proteína nas rações. Contudo, a digestibilidade de potássio, ferro e manganês reduziu a partir do aumento do nível de proteína nas rações. O presente estudo indicou que o aumento do nível de proteína em rações para juvenis de matrinxã melhorou a digestibilidade dos nutrientes. Nossos resultados indicaram que 40% de proteína bruta nas dietas apresentaram melhores resultados. No entanto, o aumento exacerbado dos níveis de proteína e, consequentemente nitrogênio, nas rações pode causar desequilíbrios metabólicos, enfraquecendo a absorção e aproveitamento de alguns nutrientes, como os microminerais.