How to solve the problem of scales to improve the efficiency in livestock production?
Résumé
It is essential to consider environmental and resource issues in livestock farming systems for the future of
animal production. However, research on farming systems and their relationship to the environment are
complex. Accounting for environmental and resource issues usually starts from improving the constituent
elementary processes (animal, culture), applying these to the farm system and then aggregating these at the
sector or territory level. Although this bottom-up approach may seem logical, the extrapolation of solutions
of lower levels does not guarantee their relevance at a more aggregated level. This report illustrates the
aggregation problem with examples concerning greenhouse gas mitigation in dairy production, but the
problem applies to other environmental topics, such as eutrophication. In cattle, milk and meat production are
inseparable issues to optimize the use of feed resources and reduce environmental impacts. Improving one
sector without considering the other can lead to inefficient aggregated solutions. This lack of conservation
of properties of solutions at different levels of aggregation comes from interactions among entities within
the aggregation. Optimizing efficiency by sector or industry promoting the use of the best resources to
improve efficiency could lead to increase competition on edible foods for humans. The proposed strategy
consists to study first the optimal allocation of resources and agricultural land use by various production
systems for the different territories with their agronomic potentials and environmental constraints. After
defining the optimal allocation, the search for a better efficiency within each sector becomes relevant.
Finally, it is necessary to ensure that improved systems fit with the objectives. The strategy of successively
combining a top-down strategy with a bottom-up approach between the levels of organization is probably
more consistent to identify the optimal solutions for the global food system than the up-scaling strategy.