Bio-economic evaluation of dairy farm management scenarios using integrated simulation and multiple-criteria models

Appropriate selection of holistic management strategies for livestock farmi ng systems requires: (1) under-standing of the behaviour of, and interrelat ions between, the different parts of the system; (2) knowledge of the basic objectives of the decision maker managing such enterprise; and (3) underst anding of the system as a whole in its agro-ecoregional context. A decision -support system based on simulation and mathematical programming techniques has been built to represent pastoral dairy production systems. The biologi cal aspects (grass growth, grazing, digestion and metabolism, animal perfor mance) are represented by simulation studies under a variety of management regimes. The outputs from the simulation runs (such as pasture utilisation, stocking rates, milk yields, fertilizer use, etc.) are used as data input to the multi-criteria decision-making models, and the latter have been used to select the management strategies which make the most efficient use of t he farm's resources (i.e, land, animals, pastures). The paper discusses the effects and implications of different management scenarios and policies on the bio-economic performance of highland dairy farms in Costa Rica. Nevert heless, the model frameworks are generic and can be adapted to different fa rming systems or ruminant species. The effect of model formulation and sens itivity, different decision-maker objectives, and/or activity or constraint definitions on management strategy selection are also analysed. (C) 2000 E lsevier Science Ltd. All rights reserved.