The declining profitability of agriculture and livestock production, increasing climatic variations, and growing concern over the environmental impact of farming challenge farm management. In this context, we propose a generalized mathematical bioeconomic macro model for livestock production systems. This model resulted from a multidisciplinary effort to integrate major databases of climate, soil, plants, animals, and their economic aspects, searching for representing a livestock production similar to Brazilian systems of pasture-based beef cattle production. This work is divided into four submodels: (i) herd structure and animal characteristics; (ii) animal nutrient requirements; (iii) meteorological–soil–pasture–animal integration; and (iv) economic. We adopted the system dynamics modelling methodology, composed of differential and integral equations in structured iThink 9.1.4 software. The equations herein proposed were adapted from pre-existing studies, and we intend to include them into a macro model in the future and use them to build different scenarios based on real data. Copyright © 2014 John Wiley & Sons, Ltd.