The animal science systems group at Texas A & M University (TAMU) has developed a computer based beef cattle production model for use in tropical countries. This model can be used to predict animal and herd productivity under a variety of management regions in diverse environments. Economic analyses can then be made, based on these predictions.

The important position and role of mixed farming systems in land use intensification in subSaharan Africa is reviewed. This is done by examining the current situation that is followed with a justification for mixed farming. Further sections follow on changing patterns of land use, including the effects of tsetse flies and trypanosomiasis, and on constraints to further crop-livestock integration.