Impacts productive, environmental and economic of the supplementation strategies of the diet of beef cattle under grazing heights and termination strategies

Abstract

The growing concern over the environmental impacts caused by livestock generates the demand for information that can address the questions of the world population, and address this important economic activity in the efficient management of production resources. Grazing management, combined with techniques of food supplementation can increase the efficiency of nutrient utilization and available resources in livestock systems, thereby reducing environmental impacts and increasing the financial return. The objective of this study is to evaluate the effects of production, environmental and economical rearing of beef steers on pasture supplemented, and strategies for finishing in the dry season. Will be used 18 paddocks of Brachiaria brizantha cv. Marandu grazed to 15, 25 and 35 cm for steers in the growing phase under continuous stocking with variable stocking rate during the rainy season, water and transition / dry. Will be used supplementation strategies, and mineral supplement in the amount of 0.3% BW (body weight) in the pasture of 25 and 35 cm, 0.3 and 0.6% of PC in pastures of 15 cm. The design is completely randomized design with repeated measures on time, in periods of 28 days. Will be measured structural characteristics and nutritional value of pasture, forage intake and supplement, weight gain and methane emissions by animals per unit of product in each system. In the dry period, half of the animals of each treatment will be finished in confinement, and the other half in the pastures, receiving 1.0% of PC supplements. Methane emissions from animals will be measured, in order to determine the best strategy for management of grazing, supplemental feeding, and finishing system on reducing emissions of greenhouse gases by beef cattle.