ABSTRACT:The economic viability of feedlot Aberdeen Angus steers fed with diets composed of different concentrate levels (CL) in dry matter (25, 40, 55 or 70%) was estimated using Monte Carlo simulation combined with Spearman rank correlation, considering nine random input variables, as well as stochastic dominance (DOM) and sensitivity (SENS) analyses. For the financial indicator simulation, net present value (NPV), cash flow with indicators of performance, and the probability distribution of all cost and income items (from 2003 to 2014) were used. Latin hypercube sampling and a Mersenne Twister random number generator was employed for the simulation, which included 2000 interactions. The expected mean values ± standard deviation for NPV (USD/animal) were 44.94 ± 68.01, 44.50 ± 69.25, 15.39 ± 69.22 and 54.20 ± 71.58 for the diets containing 25, 40, 55 and 70% CL, respectively. The probability of NPV ≥ 0 was 76.8, 76.0, 57.9 and 78.1%, respectively, from the smallest to largest CL. The DOM analysis showed that 25 and 40% CL have similar probability curves, the 70% level dominated the remaining and all CL dominated 55%. According to SENS analysis, the items that most influenced the NPV were, in decreasing order, finished and feeder cattle price, initial and final weights, concentrate and roughage price, concentrate intake, minimum rate of attractiveness and roughage intake. Based on the simulation results, the 70% CL showed a higher NPV and greater likelihood of economic viability. The probabilistic simulation technique is an interesting tool for decision-making in investment projects with beef cattle feedlot, therefore, further studies in this line of research is recommended.

ABSTRACT:The economic viability of feedlot zebu bulls, slaughtered at 450 kg after 90 days of feeding with diets consisting of different proportions of concentrate in dry matter (40, 60 or 80%), was estimated using Monte Carlo simulations, with or without the inclusion of Spearman rank correlations among random input variables, stochastic dominance (DOM) and sensitivity analysis (SENS). The roughage used was chopped sugar cane. Cash flow with indicators of performance, and probability distributions of all items of cost and revenue (from 2003 to 2014), were used to stimulate net present value (NPV), the financial indicator. Latin hypercube sampling and a Mersenne Twister random number generator were employed for the simulation with 2000 interactions. The risk was found to be more accurately estimated when correlations between random input variables were included (probability of NPV ≥ 0 ± standard deviation was 35 ± 166.05% and 31 ± 139.75% for the simulation without and with correlation, respectively). Considering this result, DOM and SENS were only carried out including these correlations. The expected value for NPV was similar between the different levels of concentrate (average USD -62/animal and NPV ≥ 0 of 33%) according to DOM analysis of simulations including correlations. From the SENS analysis, the final weight, finished cattle price, feeder cattle price and initial weight were the items with the greatest influence on NPV, regardless of the level of concentrate used, followed by intake and the cost-related items of diet and minimum rate of attractiveness. Based on the results obtained by simulation, the direct benefit of feedlot could be classified as high risk, suggesting the increased use of Monte Carlo simulation for decision-making.

ABSTRACT:The objective of this study was to evaluate the use of stochastic simulations in decision-making regarding the economic viability of feedlot finishing Charolais steers slaughtered at different weights (420, 460 or 500 kg live weight). Monte Carlo simulation was used, with or without Spearman correlation, to evaluate the risk associated with random input variables, and to compare the curves of pairs of slaughter weights by stochastic dominance. The financial indicator net present value (NPV) was the output variable. The expected means and standard deviations for the slaughter weights of 420, 460 and 500 kg were USD 28.77 ± 53.90; USD 36.27 ± 57.22 and USD 54.60 ± 66.74 for simulation with correlation, and USD 28.75 ± 96.15; USD 36.17 ± 103.11 and USD 54.53 ± 111.96 for simulation without correlation. The simulations without correlation were found to overestimate the standard deviation by 75% compared to simulations performed in addition to correlation analysis. The correlation between random input variables should be prioritized, as this resulted in better estimates of risk associated with investment. For all simulated situations, the lowest slaughter weights dominated the largest, according to the first-and second-order stochastic dominance criteria. For the simulation with correlation, the probability of NPV ≥ 0 was 29.4, 24.4 and 19.4% for slaughter weights of 420, 460 and 500 kg, respectively. Interpretation of these simulations allowed classification of feedlot technology as high risk, with a high probability of economic loss.

The objective of this study was to evaluate various financial indicators, estimated deterministically (considering historical quotes twelve consecutive years - 2003 to 2014), on the economic feasibility of finishing steers commercialized with different weights, using the simulation technique. Performance data steers were simulated with average initial weight of 350kg, fed in feedlot and slaughtered with 410, 440, 470, 500, 530, 560 and 590kg. The feeding period varies from 46 to 185 days, respectively. Based in various economic indicators, the viability of the investment decreased linearly according to the increase in slaughter weight. The coefficient of simple linear regression and means from lowest to highest slaughter weight were, respectively: net present value (-0.538 and R$ 67.37, R$ 65.28, R$ 32.14, R$ -7.34, R$ 8.01, R$ -12.38, R$ -23.41); index benefit: cost (-0.0003 and R$ 1.042, R$ 1.039, R$ 1.014, R$ 1.006, R$ 1.003, R$ 0.995, R$ 0.991); additional return on investment (-0.009 and 1.38, 1.29, 0.35, 0.11, 0.05, -0.08, -0.13% per month); internal rate of return (-0.009 and 2.21, 2.10, 1.28, 0.80, 0.93, 0.78, 0.73% per month). Feedlot use as termination option to obtain the direct benefits of this technology is an alternative investment with low economic return.

This work aimed to compare the competitive ability of canola hybrids susceptible (conventional) or resistant to triazine or imidazolinone group herbicides, with turnip. The experiments were conducted in greenhouse, in a completely randomized design, with four replicates. The hybrids Hyola 571CL (resistant to imidazolinone), Hyola 555TT (resistant to triazine), and Hyola 61 (conventional) were used. The treatments consisted of ratios (100:0; 75:25; 50:50; 25:75; 0:100%) of canola and turnip plants. The evaluation was performed 44 days after emergence, determining the leaf área (AF), dry matter of aerial part (MSPA), and stature (EST) of the plants. The competitiveness analysis was performed through diagrams and interpretation of the competitiveness indexes. For the canola hybrids, the competition occurred by the same mean resources. There was damage to the crop growth in competition with the turnip. The turnip was not benefited only when in competition with Hyola 571CL hybrid, for the EST variable, and with the conventional canola, for the variable AF. There was significance for the competitiveness indexes, demonstrating that turnip is more competitive then the crop. Greater AF, MSPA, and EST occurred for canola plants in the smallest proportions of turnip and, for turnip plants, in the largest proportions of canola. The ability to compete with turnip is similar among hybrids, with injury to the crop and benefit to the weed, when competing. Interspecific competition is more damaging to canola hybrids; and intraspecific competition is more damaging to turnip.