Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-10-25T16:19:22Z No. of bitstreams: 1 2012 - Danilo Antonio Morenz.pdf: 638093 bytes, checksum: 3b4f1d143b088953006c8246815bb7b1 (MD5) / Made available in DSpace on 2017-10-25T16:19:25Z (GMT). No. of bitstreams: 1 2012 - Danilo Antonio Morenz.pdf: 638093 bytes, checksum: 3b4f1d143b088953006c8246815bb7b1 (MD5) Previous issue date: 2011-11-20 / CNPq / The objective of this study was to evaluate the variables related to the heights in the pre and post grazing sward, the production of dry biomass of green forage, morphological composition, leaf:stem ratio and nutritive value of two clones of elephant grass managed under rotational stocking. Was adopted a completely randomized design with repeated measures in time (grazing cycles) and three replications (paddocks). The sward heights, in pre and post grazing were influenced by the clones and grazing cycles, being the highest values observed for clone CNPGL 03-01-00. The production of dry mass of green forage was influenced by clone and grazing cycle, with higher mean value observed for CNPGL 03-01- 00, which was 17% higher than that observed for CNPGL 92-198-7, and there was decreased of dry mass of green forage with the advance of grazing cycles. The production of dry matter of leaves was influenced only by grazing cycle, with gradual reduction from the first to the third cycle. However, in fourth cycle was increase in biomass of leaves, which did not differ from that observed in the second cycle. There was interaction clone x cycle for the production of dry matter of stem, being observed differences in the first and third cycles for the clones. There was no effect of the factors studied for the production of senescent material. The leaf: stem ratio was influenced by grazing cycles, with interaction of the factors. The clone CNPGL 91-198-7 kept the leaf:stem ratio stable over the cycles, while clone CNPGL 1-3-00 presented a decrease in leaf:stem ratio from first until to third cycle. The number of aerial tillers was influenced by grazing cycles, increasing from the first until to third cycle, while the fourth cycle was observed decreased in the number of these tillers. The basal tillers were only effect of clones, where CNPGL 91-198-7 showed a higher number of these tillers. Crude protein (CP) and lignin (LIG) content were not affected by clones or by grazing cycles. Neutral detergent fiber (NDF) and the in vitro dry matter digestibility (IVDMD) were affected only by grazing cycles. The highest values of NDF were observed at the firsts three grazing cycles and, in the fourth grazing cycle the NDF was reduced. The IVDMD decreased until the third cycle; however, in the fourth cycle the values obtained were similar to those of the first cycle. According to results obtained the clone CNPGL 92-198-7 showed higher production of dry matter of the leaves, lower production of dry matter of stem and higher density of basal tillers, which may indicate its greatest potential for use under grazing, when compared to CNPGL 01-03-00. / Objetivou-se estudar as alturas no pr? e p?s-pastejo do dossel forrageiro, a produ??o de biomassa seca de forragem verde, a composi??o morfol?gica, a rela??o folha:colmo, a densidade de perfilhos e o valor nutritivo de dois clones de capim-elefante manejados sob lota??o rotacionada. Foi utilizado delineamento inteiramente casualizado com medidas repetidas no tempo (quatro ciclos de pastejo) e tr?s repeti??es (piquetes). As alturas do dossel pr? e p?s pastejo foram influenciadas pelos clones e pelos ciclos de pastejo. Os valores mais elevados foram observados para o clone CNPGL 00-1-3. Para massa seca de forragem verde houve apenas efeito do clone e do ciclo de pastejo. O valor m?dio da massa seca de forragem verde do CNPGL 00-1-3 foi 17% maior do que a do CNPGL 92-198-7. Com o avan?ar dos ciclos de pastejo houve redu??o da massa seca de forragem verde. A produ??o de biomassa seca de folha foi influenciada apenas pelo ciclo de pastejo, com redu??o gradual do primeiro at? o terceiro ciclo. No quarto ciclo houve aumento na massa seca de folha, que n?o diferenciou daquela obtida no segundo ciclo. Houve intera??o clone x ciclo para a massa de colmo, sendo observadas diferen?as entre clones apenas no primeiro e terceiro ciclos. N?o foi observado efeito dos fatores estudados ou intera??o para a massa seca de material morto. A rela??o folha:colmo foi influenciada pelos ciclos de pastejo, havendo intera??o dos fatores estudados. O CNPGL 92-198-7 manteve a rela??o folha:colmo est?vel ao longo dos ciclos, enquanto que o CNPGL 00-1-3 apresentou decr?scimo na rela??o folha:colmo do primeiro at? o terceiro ciclo, com maior valor obtido no quarto ciclo. Quanto ao n?mero de perfilhos a?reos foi observado efeito dos ciclos de pastejo, com aumento do primeiro ao terceiro ciclo, enquanto que no quarto ciclo houve redu??o do n?mero desses perfilhos. Para os perfilhos basais houve efeito dos clones, onde o CNPGL 92-198-7 apresentou maior n?mero de perfilhos que o CNPGL 00-1-3. Os teores de prote?na bruta (PB) n?o foram influenciados pelos clones ou pelos ciclos de pastejo. Os teores de fibra em detergente neutro (FDN) e o coeficiente da digestibilidade in vitro da mat?ria seca (DIVMS) foram influenciados apenas pelos ciclos de pastejo. Os maiores valores de FDN foram observados nos tr?s primeiros ciclos de pastejo, j? no quarto ciclo de pastejo o teor de FDN reduziu. Quanto ? DIVMS houve queda at? o terceiro ciclo, enquanto que no quarto ciclo os valores obtidos foram semelhantes aos do primeiro ciclo. Para lignina n?o foi observada diferen?a dos fatores estudados. De acordo com os resultados obtidos, o clone CNPGL 92-198-7 apresentou maior produ??o de biomassa seca de folhas, menor produ??o de biomassa seca de colmo e maior densidade populacional de perfilhos basais, o que pode indicar seu maior potencial para uso sob pastejo, quando comparado ao CNPGL 00-1-3.