A beef production model for the savannas of Colombia : Model description and user notes

A fully interactive beef production model is described. The beef component is based on the Kahn model built at Reading University, which itself originally shared a limited number of features with the Texas A and M model of the late 1970s. Herds of up to 30 animals may be handled for up to 20 years of simulated time. The model is flexible, and the structure allows sub grazing, rotational grazing, and grazing among multiple forage species. Animals may be bought, sold, culled or weaned as required. Cash flows are produced, along with net present values and internal rates of return, and for any particular run, economic re-analysis may be carried out to investigate changes in economic parameters. Provision also exists to investigate dual-purpose beef-milk systems. The major relationships within the model are documented, its use illustrated, and output files are described. (RA)