The study aimed to evaluate milk production under grazing system in the North Region of Rio de Janeiro State. The net present worth (NPWs of 6 and 10%) and internal rate of return (IRR) were calculated from the cash flow chart on a 20-year basis. Sensitivity analyses were performed to evaluate the effect of the income or expense factors on the net present worth (6 and 10%) and the internal rate of return. A Monte Carlo Method was carried out to evaluate the probabilities of occurrence for certain financial values associated to the risk of deviation in the project itens. The results showed financial feasibility for the proposed system (NPWs of 6% and 10% R$197,880.00 and R$8,067.00, respectively; IRR 10.2%). The profitability was affected in decreasing order by the following factors: price of milk, purchase of cows in the first years of the project, price of culled cows, labor and the price of the concentrate for adult animals. The results of the Monte Carlo simulation indicated high probabilities (39%) of the profitability to be smaller than the interest of the saving account, showing high economic risk of the production system.
milk production; grazing system; sensitivity analysis; Monte Carlo method; internal rate of return; net present worth
