Gustavo Dal Forno Gianluppi

Componentes morfológicos e produção de forragem de pastagem de aveia e azevém manejada em diferentes alturas

Forage growth dynamic in an Oat (Avena strigosa, Schreb) + Ryegrass (Lolium multiflorum, Lam) pasture managed at different grazing heights was evaluated in order to access the mixed-sward potential in a crop-livestock integrated system. Treatments were four sward grazing heights (10, 20, 30, and 40 cm), measured with a sward-stick. The experimental design was a random block with three replications. The grazing method utilized was continuous stocking with variable stocking rate. Beef steers weighting 210 kg with approximately 10 month old were used. The analyzed variables were herbage mass (HM), herbage growth rate (GR), dry matter production (DMP), and the morphological components (stem, leaf and senescent material). A linear increase was observed for herbage mass as herbage height increased. Results showed that for every centimeter in sward height above 10 cm means approximately 90 kg DM/ha. Treatments did not affect the GR and the DMP, and the average values were 66.8 kg DM/ha/day and 10,721 kg DM/ha, respectively. Ryegrass leaf presented greater proportion than oat leaf in the three evaluation periods, showing higher values for the treatment 10 cm in the last evaluation (about 20% of participation in the total biomass). Oat presented a fast initial development and decreased the production on the later periods.

Terminação de cordeiros em pastagens de azevém anual manejadas em diferentes intensidades e métodos de pastejo

This work measured lamb performance in a ryegrass pasture (Lolium multiflorum Lam.) under different grazing intensities and methods. The pasture was used from July 12th to November 1st of 2003 (total of 113 days). The treatments were two grazing intensities (moderate and low) in rotational and continuous stocking. The moderate and low grazing intensities were represented, respectively, by forage allowance of 2.5 and 5 fold the intake potential. It was used a factorial arrangement (2 intensities × 2 methods × 4 replicates) in a complete randomized block design. There was no interaction among grazing methods and grazing intensities and they were analyzed separately. The moderate grazing intensity provided the lower forage allowance, lower herbage mass and lower pasture height. This intensity affected positively the qualitative characteristics of pasture as well. Regarding the grazing methods, the height and the herbage mass were larger under rotational stocking, while the forage quality was higher under continuous stocking. There was no difference of forage allowance between methods, and the necessary conditions to compare all the variables measured were reached. There were significant differences between average daily gain and stocking rates on both, grazing methods and intensities. The gain/hectare was better under moderate grazing intensity, but no difference was identified under grazing methods for this intensity. The amount of forage available for the animal is the central key for the productivity, despite the grazing method used. Low grazing intensity was considered more appropriate for pasture management because it allows better gain per animal.