Morfogênese, estrutura e dinâmica de perfilhamento de capim-tanzânia manejado com diferentes IAF residual, sob pastejo de cabras Anglonubiano

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Características morfogênicas do dossel de Brachiaria brizantha (Hochst ex. A. Rich.) cv. Marandu manejada com diferentes ofertas de forragem sob lotação intermitente

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Alturas de pastos de capim-marandu na interface solo-planta

Pós-graduação em Zootecnia - FCAV

Características estruturais do dossel, produção de forragem e desempenho de cordeiros em pastos de tifton 85 sob lotação intermitente

Pós-graduação em Zootecnia - FCAV

Comportamento ingestivo de bovinos mantidos em pastos de Brachiaria brizantha cv. Xaraés manejado em diferentes alturas de pastejo

This experiment was conducted to evaluate the effect of grazing heights on daytime behavioral activities of Nellore beef cattle in the rainy season. The experimental area was 12 hectares divided into paddocks of one hectare each. The treatments consisted of four defoliation heights (15, 30, 45 and 60 cm) in pastures of Brachiaria brizantha cv. Xaraes with three replicates each. It was used the continuos grazing method, with variable stocking rate. Forage samples collected on the plots were sent to the laboratory for separation of the botanical components, weighing and determination of dry matter, with the material collected by simulated grazing. The variables: grazing time, idle time and ruminating time were evaluated for 12 consecutive hours on days 15 and 16 February 2011, considering the morning and afternoon periods. It was used a completely randomized design. The height of the canopy significantly influenced the daily grazing time and ruminating time, with a quadratic response as a function of time of defoliation. The bite rate decreased as a function of heights studied. However the chemical composition of the material collected by simulated grazing did not differ between treatments. Xaraes grass swards grazed at around 45 cm height provide greater ease of apprehension by grazing cattle.

Produção de forragem e composição estrutural de pastos de Brachiaria brizantha cv. Xaraés manejados em diferentes alturas de pastejo

The objective of this study was to analyze the production of dry mass, forage accumulation rate and the structural composition of Brachiaria brizantha cv. Xaraes pastures, managed under different grazing heights in continuous stocking. The experimental area was 12 hectares, divided in paddocks of one hectare each. The treatments were 15, 30, 45 and 60 cm of defoliation heights. Nellore steers were used to reach the desired heights. Every 28 days four cut samples and eight visual samples were collected for comparative performance in the experimental plots. Two grazing exclusion cages were used per treatment to estimate accumulation rates kg.ha(-1) DM. The cut material was taken to the laboratory for separation of the botanical components (green leaf, stem and senescent material), weighing and determination of dry matter. The experimental design was the completely randomized with three replicates. There were treatments effects at all seasons for the production of total mass, except in the spring. In summer and spring seasons it was observed the highest values for leaf blades (1.100 kg DM.ha(-1)). In the winter, the highest values of senescent material was observed, as expected. The average accumulation showed no significant difference among the treatments, except for stem and total mass in the summer and stem in the fall. The tillers were heavier and higher values for number of green leaves per tiller occurred in the fall, but for senescent leaves per tiller ocurred in the winter. Swards grazed at heights between 45 and 60 cm of defoliation, had good production of forage mass and leaf constituent.

Virginiamycin via mineral supplementation and sward height in growing Nelore young bulls

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)