Different economic viability of pasture production systems to heifers grazing elephantgrass pasture in North Fluminense region wa analyzed. The economical analysis of three systems of growing fedlot dairy heifers grazing elephantgrass pasture was performed. In order to study the hazard that each system can present due to the oscillations of prices in the market, Monte Carlo simulation was used. The systems studied were: without supplementation (PS1), offer of 0.5% of the alive weight of concentrate (PS2), and alternate pasture of elephantgrass and Stylosanthes (PS3). The analysis was based on the economical indicators Net Present Value (NPV) and Internal Rates of Return (IRR). The NPV calculated at an annual rate of discount of 10%, were R$ 6,091.86, R$ 6,364.54 and R$ 215.43, while the invested capital showed yearly IRR of 29.58, 30.10 and 10.46%, respectively for three systems studies. The sensitivity analysis was used to identify the items of larger economical impact and that presented great effect on the profitability of the systems. In order of importance, the sale price of heifers, the purchase price of heifers and the labor cost were the items with greater impact on the economical results. It was concluded that the PS3 showed the highest economical stroke.
elephantgrass; internal rates of return; Monte Carlo simulations; net present value; sensibility analysis; supplementation
