Energy Assessment of Pastoral Dairy Goat Husbandry from an Agroecological Economics Perspective. A Case Study in Andalusia (Spain)

Abstract

This paper presents a methodological proposal of new energy sustainability indicators according to a novel accounting that follows agroecological and ecological economics criteria. Energy output is reformulated to include manure and thus consider the contribution to fertilization made by pastoral livestock farming to agroecosystems. Energy inputs calculations include the grazing resources. These new definitions and calculations allow for new formulations of the energy return on investment (EROI) as measures of the energy efficiency of livestock farming systems (final EROI and food/feed EROI). The environmental benefit of manure is estimated from the avoided energy cost of using this alternative to inorganic fertilizers (AEC_M). The environmental benefit of grazing is measured through the energy cost of avoiding cultivated animal feed (AEC_P) and its impact in terms of non-utilized agricultural area (ALC_P). The comparative analysis of different livestock breeding systems in three pastoral dairy goat farms in the Sierra de Cádiz in Andalusia, southern Spain, reveals the analytical potential of the new energy sustainability indicators proposed, as well as the potential environmental benefits derived from territorial-based stockbreeding and, more specifically, grazing activities. Those benefits include gains in energy efficiency, a reduction of the dependence on non-renewable energy, and environmental costs avoided in terms of energy in extensive pastoral systems.