Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-10-04T23:03:14Z No. of bitstreams: 1 JoelmaDaSilvaSouza_DISSERT.pdf: 871768 bytes, checksum: ea7d55c0815981862907bc0386df818b (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-10-16T19:24:00Z (GMT) No. of bitstreams: 1 JoelmaDaSilvaSouza_DISSERT.pdf: 871768 bytes, checksum: ea7d55c0815981862907bc0386df818b (MD5) / Made available in DSpace on 2017-10-16T19:24:00Z (GMT). No. of bitstreams: 1 JoelmaDaSilvaSouza_DISSERT.pdf: 871768 bytes, checksum: ea7d55c0815981862907bc0386df818b (MD5) Previous issue date: 2016-02-18 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Objetivou-se avaliar as caracter?sticas estruturais e o desempenho animal em pastos de capim-massai manejado com dois n?veis de intercepta??o de luz e duas alturas de p?s-pastejo, sob lota??o intermitente. Os tratamentos avaliados foram: 90/15; 95/15; 90/25; 95/25. Os animais foram manejados pelo m?todo de pastejo intermitente, com taxa de lota??o vari?vel. O in?cio do per?odo de ocupa??o dos piquetes foi determinado pelo n?vel de intercepta??o de luz pelo dossel, e o final pela altura p?s-pastejo. Foram avaliadas a massa de forragem total no pr? e p?s-pastejo, as porcentagens de participa??o dos constituintes morfol?gicos, as taxas de ac?mulo de forragem, o consumo total de mat?ria seca, o ganho de peso vivo m?dio di?rio e o ganho de peso vivo total. O comportamento ingestivo dos ovinos foi avaliado em intervalos de cinco minutos, determinando-se o tempo despendido em pastejo, rumina??o, ?cio (minuto) e taxa de bocado (bocado/minuto). N?o houve diferen?as significativas para o per?odo de ocupa??o dos piquetes com m?dia de 11 dias. Os pastos manejados com as combina??es 90/15, 90/25 e 95/25 apresentaram maiores porcentagens de folhas no pr?-pastejo. N?o houve diferen?a entre tratamentos e ciclos de pastejo para o ac?mulo e taxa de ac?mulo de forragem com m?dias de e 6344,9 kg/ha e 116,4 kg/ha.dia respectivamente. Houve efeito de ciclo para o peso final dos ovinos. Houve efeito das combina??es de frequ?ncias e intensidades de pastejo para o ganho m?dio di?rio, os maiores ganhos foram observados nos animais mantidos nos pastos com 90/15, 90/25 e 95/25 (137, 153 e 154 g dia-1, respectivamente). A taxa de lota??o n?o diferiu entre os manejos com m?dia de 49.7 cabe?as (30kg) ha-1. Houve efeito de comportamento dos ovinos para tempo de pastejo, rumina??o, ?cio e taxa de bocados. O manejo do pastejo do capim-massai para ovinos em sistema intermitente que promove melhor desempenho animal e maior efici?ncia de utiliza??o da forragem est? associado ao n?vel de intercepta??o de luz e altura de p?s-pastejo de 90/15, 90/25 e 95/25. / The objective of this study was to evaluate the structural characteristics and the animal performance on capim-massai grass pastures under two light interception levels and two post-grazing canopy heights under intermittent stocking. Treatments were: 90/15; 95/15; 90/25 and 95/25. Intermittent grazing method and variable stocking rate were used to manage the grazing animals. The animals start grazing the paddocks was determined by the canopy?s light interception level and the end of grazing by the post-grazing canopy height. Total forage mass before and post-grazing, percentages of morphological plant constituents, forage accumulation rates, total dry matter intake, average daily live weight gain and total live weight gain were evaluated. The ingestive behavior of the sheep was evaluated at five minutes intervals to measure the time spent in grazing, ruminating, idling (minute) and bite rate (bites / minute). There was no significant difference for rotation period of paddocks with 11 days in average. The pastures managed with the 90/15, 90/25 and 95/25 combinations showed higher leaf percentages in pre-grazing. There was no difference between treatments and grazing cycles for total and rate of forage accumulation with averages of 6,344.9 kg / ha and 116.4 kg / ha.day, respectively. There was a grazing cycle effect for the final weight of the sheep. There were effects of frequency combinations and grazing intensities for the average daily gain, the highest gains were observed in the animals grazing pastures with 90/15, 90/25 and 95/25 (137, 153 and 154 g day -1, respectively). The stocking rate did not differ between treatments with a mean of 49.7 head (30kg/head) ha -1. There was an effect of sheep behavior for grazing time, rumination, idling and bite rates. The grazing management of capim-massai for sheep on an intermittent stocking systems that promotes better animal performance and greater efficiency of forage utilization is associated to light interception level and post-grazing canopy height of 90/15, 90/25 and 95/25.

Made available in DSpace on 2016-04-28T14:59:45Z (GMT). No. of bitstreams: 1 2008 - Ana Paula Pessim de Oliveira.pdf: 1134139 bytes, checksum: e35252b70432f1b09c9e114425df2810 (MD5) Previous issue date: 2008-07-11 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The effects of nitrogen (N) application on several structural and nutritional attributes of the plant canopy were evaluated. The studies were carried out at the Experimental Campus of the Rio de Janeiro Federal Rural University, Serop?dica-RJ, in area of Planosol Haplic occurrence, during the period of October 2006 to July 2007. Treatments consisted of five doses of N (0; 150; 300; 450 and 600 kg N-urea/ha) disposed in experimental units of 4 x 4 m using a entirely randomized block design. After a standardization cut, made 82 days after planting, it proceeded to the application of nitrogen fertilizer levels, half of which at 94 days, and the remaining at 139 days after the planting. Four studies had been carried through, which the results are presented in distinct chapters. In the first chapter the results of nitrogen fertilization were discussed in terms of soil covering, leaf area index (LAI) and solar radiation interception, during the four sequential cuts, between the months of February and July of 2007. Weekly evaluations were accomplished, between 10 and 40 days after cut. The LAI frequency of occurrence, plant height, green cover index and level of photosynthetically active radiation intercepted showed significant responses to N fertilization, according to a logistic pattern and also varied seasonally within each cut, evidencing different sensibility as indicators for structure and growth of the Tifton 85 sward. In the second study were evaluated the effect of N fertilization on biomass production and the efficiency in the use of N absorbed. For statistical analysis purposes, sampling data were clustered in two seasons: rainy season (February to April) and dry season (April to July). It was quantified in each cut date the production of green and dry mass, leaves and stem fraction, as well as the N content in each one of the vegetative fractions. This study showed that N fertilization icreased the dry matter production and stimulated the production of leaves and stems in both the seasons (rainy and dry). However, the nitrogen fertilization, per se, does not modify the partition of the dry mass produced by leaves and stems, and had no influence on efficiency of the pasture to produce dry matter per unit of N absorbed. The third study, of methodological character, aimed the validation of indirect procedures for estimate the functional relation between the green and dry mass and the LAI. The occurrence frequency and the index of green covering were tested as substitutes of IAF using simple correlation procedure. Although in this study has been observed the existence of a significant association among the the canopy attributes estimates associated to the leaf area and the forage production leaf area and forage production, additional studies are necessary to improve the reliability and accuracy of this estimates. Finally, in the last study, the influence of the nitrogen fertilization on nutritional value of the forage was evaluated. The crude protein, neutral detergent fiber, acid detergent fiber, lignin, cellulose and hemicelulose cotents were determined. The results showed that the addition of N improved the forage quality, increasing crude protein contents and decreasing fibrous fraction. / Foram avaliados os efeitos da aplica??o de nitrog?nio (N) sobre uma s?rie de atributos estruturais e nutricionais do dossel. Os estudos foram desenvolvidos no campo experimental da Universidade Federal Rural do Rio de Janeiro, munic?pio de Serop?dica- RJ, em ?rea de ocorr?ncia de Planossolo. O experimento foi conduzido sob regime de cortes, durante o per?odo de outubro de 2006 a julho de 2007. Foram estudadas cinco doses de N (0; 150; 300; 450 e 600 kg/ha) em diferentes ?pocas do ano. O experimento foi conduzido em blocos inteiramente casualizados. Foram feitos quatro estudos, cujos resultados s?o apresentados em cap?tulos distintos. No primeiro cap?tulo, os efeitos da aduba??o nitrogenada s?o discutidos em termos de cobertura do solo, ?ndice de ?rea foliar e intercepta??o da radia??o solar, no curso de quatro cortes seq?enciais, entre os meses de fevereiro e julho. As avalia??es foram realizadas, semanalmente, entre o 10o e o 40o dia ap?s o corte. Em cada corte, o ?ndice de ?rea foliar (IAF), a freq??ncia de ocorr?ncia, altura de planta, ?ndice de cobertura verde e o n?vel de radia??o fotossinteticamente ativa interceptada, responderam ? aduba??o nitrogenada, conforme um padr?o log?stico e variaram sazonalmente, evidenciando uma sensibilidade diversa como indicadores da estrutura e do crescimento da pastagem de Tifton 85. No segundo estudo foram abordadas as respostas relativas ? produ??o de biomassa sob aduba??o nitrogenada e a efici?ncia na utiliza??o do N absorvido. Para efeito de an?lise estat?stica, os dados das coletas foram agrupados em ?poca das chuvas (fevereiro a abril) e ?poca seca (abril a julho). Em cada data de corte foi quantificada a produ??o de massa verde e seca, a sua parti??o entre folhas e colmos + bainhas, assim como o teor de N em cada uma das partes vegetativas. Este estudo evidenciou que a aduba??o nitrogenada aumentou a produ??o de forragem, estimulando a produ??o de folhas e colmos tanto na ?poca chuvosa quanto na seca. Por outro lado, a aduba??o nitrogenada, per se, n?o modificou a parti??o da massa seca produzida por folhas e colmos, nem influenciou a efici?ncia com a qual a pastagem produz massa seca por unidade de nitrog?nio absorvido. O terceiro estudo, de cunho metodol?gico, objetivou a valida??o de procedimentos indiretos para a estimativa da rela??o funcional entre a massa verde e seca e o ?ndice de ?rea foliar da pastagem. Foram estudados a freq??ncia de ocorr?ncia e o ?ndice de cobertura verde como suced?neos do IAF, utilizando-se correla??o simples. Embora tenha sido observada a exist?ncia de um grau de associa??o significativo entre as estimativas de atributos ligados ? ?rea foliar e a produ??o de forragem, s?o necess?rios estudos adicionais para melhorar a confiabilidade e a acur?cia de tais estimativas. No quarto estudo foi estudada a influencia da aduba??o nitrogenada sobre o valor nutricional da forragem, sendo avaliados os teores de prote?na bruta, fibra em detergente neutro, fibra em detergente ?cido, lignina, celulose e hemicelulose. Os resultados obtidos mostraram que a adi??o de N melhorou a qualidade da forragem, aumentando os teores de prote?na bruta e reduzindo a fra??o fibrosa.

Made available in DSpace on 2016-04-28T14:59:45Z (GMT). No. of bitstreams: 1 2008 - Leandro Galzerano.pdf: 1398173 bytes, checksum: 3b9bc8540a1e5f744b54fffefe6a7828 (MD5) Previous issue date: 2008-08-05 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This work was carried out in order to obtain subsidies under the definition of strategies for nitrogen fertilization of pastures of tifton 85, based on monitoring the dynamics changes in the structure of swards. The underlying assumption was that the application of increasing levels of N is a powerful tool for that purpose. The experiment was developed over a Planosol of occurrence in the experimental field of the Universidade Federal Rural Rio de Janeiro, city of Serop?dica, Brazil, during the establishment of the pasture, between the months of October, 2006 to January 2007. Treatments consisted of four levels of N (0, 50, 100 and 150 kg N-urea. ha-1), in single application, in plots of 4 x 4 m, arranged in blocks fully randomized, with four repetitions. Together with nitrogen fertilization, the plots received 80 kg P.ha-1 and 150 kg K.ha-1, and Ca as calcareo (1.0 tn.ha-1). The variables were: frequency of occurrence of plants; height of the canopy, leaf growth and leaf area index (LAI), the interception of photosynthetically active radiation (PAR) and the production and partition of dry matter. The results showed that the frequency of occurrence, height and interception of PAR varied according to a standard logistic, whose parameters have been modified to a greater or lesser degree, by the levels of N added. Similarly, at the 87 days after planting, the LAI and the total dry matter produced, but not its partition between leaves and stems, responded to changes in N mineral available in the soil. It was concluded that the application of increasing levels of Nurea, during the establishment of grass tifton 85 was an efficient experimental strategy for the induction of quantitative changes during the development time of swards structure. / O presente trabalho foi realizado com o prop?sito de definir estrat?gias de aduba??o nitrogenada em pastagens de tifton 85, baseadas no monitoramento de mudan?as din?micas na estrutura dos doss?is forrageiros. O experimento foi desenvolvido numa ?rea de Planossolo no campo experimental da Universidade Federal Rural do Rio de Janeiro, munic?pio de Serop?dica, RJ, durante a fase de estabelecimento da pastagem, entre os meses de outubro de 2006 a janeiro de 2007. Os tratamentos consistiram de quatro n?veis de N (0; 50; 100 e 150 kg N-ur?ia.ha-1), em aplica??o ?nica, dispostos em parcelas de 4 x 4 m, arranjadas em blocos inteiramente casualizados, com quatro repeti??es. Em conjunto com a aduba??o nitrogenada, as parcelas receberam 80 kg P.ha-1 e 150 kg K.ha-1. O solo foi corrigido com 1,0 tn.ha-1 de calc?reo. As vari?veis estudadas foram: freq??ncia de ocorr?ncia de plantas; altura do dossel, crescimento foliar e ?ndice de ?rea foliar (IAF), intercepta??o de radia??o fotossinteticamente ativa (RFA) e produ??o e parti??o da mat?ria seca. Os resultados obtidos mostraram que a freq??ncia de ocorr?ncia; altura e a intercepta??o de RFA variaram temporalmente de acordo com um padr?o log?stico, cujos par?metros foram modificados, em maior ou menor grau, pelos n?veis de N adicionados. De forma similar, aos 87 dias p?s- plantio, o IAF e a mat?ria seca total produzida, mas n?o a sua parti??o entre folhas e colmos, responderam ?s varia??es do N mineral dispon?vel no solo. Foi conclu?do que a aplica??o de n?veis crescentes de Nur?ia, durante a fase de estabelecimento do capim tifton 85 foi uma estrat?gia experimental eficiente para a indu??o de varia??es quantitativas durante o desenvolvimento temporal da estrutura dos doss?is.