Multicriteria performance and sustainability in livestock farming systems: Functional diversity matters

Agricultural intensification drastically reduces diversity at different scales of livestock farming systems (LFS). This homogenization process leads to environmental degradation and ignores the fact that multiple performance criterions often come in conflict. Taking advantage of diversity at different scales of LFS is a new challenge to improve sustainability. The diversity is considered here on a functional viewpoint, i.e. a variety of functions played by individual production entities involved in overall performance. The objective of this study was to examine how the diversity of individual production entities shapes the relationship between different performance criterions at the upper scale. We used two types of dynamic models representing contrasting LFS: extensive grassland suckling farms and intensive dairy herds. Both models include a certain level of functional diversity with production entities corresponding to different types of management practices (grassland farm model) or different types of females (herd model). With the grassland farm model, we studied how the biodiversity/production relationship was influenced by the functional diversity of management practices. With the herd model, we explored how production/efficiency relationship was influenced by the functional diversity of females. At the farm scale, we showed that interactions between the diverse management practices shaped the relationship between ecological and productive performance from a convex to a concave trade-off. Complementary effects resulting from the diversity of management practices thus improved the trade-off. Trade-off shape also depended on the level of farm intensity and it was less costly for the extensive farms to achieve viable levels of ecological performance. Increasing the complementary effect through increased diversity in management practices is likely to improve the conciliation between productive and ecological performance. At the herd scale, we observed a win–win situation between production and efficiency. However, at the highest levels of production, there was a production/efficiency trade-off; increases in either production or efficiency corresponded to distinct functional groups of females. Managing the functional groups of females with targeted practices is likely to improve the production/efficiency trade-off. We concluded from both case studies that functional diversity plays a key role in the relationship between multiple performance criterions. The next steps on the research agenda include exploring new spatial and temporal scales and accounting for environmental variability. A better understanding of the role of functional diversity can benefit from multi-criterions and multi-scale modelling approaches.