We used simulation to study how three French sheep production systems could adapt to a new context created by a surge in cereal prices associated with changes in common agricultural policy support. The evaluation criteria were economic performance, energy efficiency, emissions of greenhouse gases, and sensitivity to technical and economic fluctuations. We found the most intensive system was the most strongly affected, while the small size system with lower animal productivity was less sensitive to unforeseen events. The farm production of part of the grain needed for the flock, with a concomitant decrease in sheep numbers, significantly improved feed self–sufficiency. This mitigated fall in income and reduced the sensitivity of income to unforeseen events. The most self–sufficient system displayed greater energy efficiency, although lowered flock productivity could cause an increase in greenhouse gas emissions per unit carcass weight.
Keywords: sheep for meat, sheep production, farming systems, agricultural economics, energy prices, adaptation, agricultural policy, simulation, modelling, self–sufficiency, sensitivity, hazards, sustainable development, sustainability, France, semi–upland areas, economic performance, energy efficiency, GHG emissions, greenhouse gases, technical fluctuations, economic fluctuations