Integrated Environmental and Energetic Benchmarking of Iranian Dairy Farms Using Emergy Analysis and Robust DEA: Toward Resilient and Eco-Efficient Milk Production

Dairy production in semi-arid regions is characterized by high resource intensity and substantial environmental pressure, necessitating rigorous sustainability assessments. This research evaluates the energy, emergy, and environmental performance of dairy systems by integrating Classical and Robust Data Envelopment Analysis (CDEA and RDEA) for multi-criteria efficiency optimization. The total energy input was estimated at 248,027 MJ·cow⁻¹·yr⁻¹, with a corresponding emergy demand of 4.12E+18 solar emergy joules (sej)·cow −1 ·yr −1 , dominated by non-renewable inputs, specifically machinery, infrastructure, and electricity. Results indicated low energy use efficiency (EUE = 0.197) and a negative net energy gain (NEG). Sustainability indices further reflected ecological vulnerability, with a Renewability Percentage (%R) of 0.32, an Environmental Loading Ratio (ELR) of 3.12E+02, and an Emergy Sustainability Index (ESI) of 4.42E–06. Environmental burdens were significant, notably a global warming potential (GWP) of 12,500 kg CO₂ eq., alongside substantial acidification (AP) and eutrophication (EP) potentials. The application of the RDEA framework provided a more stable and conservative benchmark compared to the deterministic CDEA model, identifying potential pathways to reduce total emergy use and environmental burdens by up to 28%. These findings demonstrate that the integration of biophysical accounting with robust efficiency modeling offers a scalable framework for enhancing eco-efficiency and informing sustainable policy formulation in livestock production.