Productivity, quality and nitrogen nutrition of Urochloa brizantha in pastures under continuous stocking in integrated crop-livestock-forest systems
Brachiaria, buffalo, crude protein, leaf / stem ratio, agrosilvipastoral system
Seasoning and grazing can change grazing responses, even in innovative crop-livestock-forest integration systems. The objective of this work was to evaluate the dynamics of Urochloa brizantha cv. Piatã under continuous stocking grazing in open pasture (PA), African mahogany (Khaya ivorensis) (ILPF-M) and ILPF with teak (Tectona grandis) (ILPF-T) over time and seasons . The total mass of forage, leaf, stem and mass + stem and the leaf / stem ratio, as well as the total mass crude protein, the nitrogen concentration and the accumulated nitrogen of the leaf, stem and leaf + stem fractions, were evaluated every 28 days for 252 days. Buffalo daily weight gain and stocking rate were evaluated on five occasions within this period. The total forage mass was lower in the ILPF systems than in the dry season PA system. The same was observed for leaf, stem and leaf + stem mass. In contrast, the ILPF-T system provided forage with higher crude protein content and nitrogen concentration in this season. In the rainy season no difference was observed between the systems. Forage mass decreased in all systems over time, during the dry and rainy seasons due to grazing; however the leaf / stem ratio was higher in the rainy season than in the dry season. Crude protein and nitrogen concentration also declined in each season, but both were higher in the rainy season. Both daily weight gain and stocking rate were higher in the rainy season. The season modified forage yield and quality, as well as animal performance, while grazing determined pasture dynamics in ILPF systems.