Transition among different production systems in a Sardinian dairy sheep farm: Environmental implications

Sardinia (Italy) plays a relevant role on EU sheep milk production. In Sardinia, as well as in other Mediterranean regions, there is a range of different dairy sheep farming systems and an effective renovation process is needed to tackle the deep structural crisis of the sector. The eco-innovation of production processes and the valorisation of pasture-based livestock systems can be a key strategy to improve the farms competitiveness and to promote the environmental sustainability of the typical Mediterranean dairy sheep products. For these reasons, research studies based on holistic and site-specific approaches are needed to assess the environmental implications of Mediterranean sheep systems. The main objective of this study was to compare the environmental performances of two contrasting sheep milk production systems through a Life Cycle Assessment (LCA) approach. The LCA was carried out on a farm where changes in land use (from arable and irrigated crops to native and artificial pastures) occurred over a 10-year period, in conjunction with a reduction of total supply of mineral fertilizers. The analysis was performed using IPCC and ReCiPe methodologies, and a functional unit of 1 kg of Fat and Protein Corrected Milk (FPCM). The LCA analysis showed that the change from semi-intensive to semi-extensive production system had only a slight effect on the overall environmental performances of 1 kg FPCM, due to the dominant impact of enteric fermentation in both systems. The Carbon Footprint was on average 3.12 kg CO2-eq per kg FPCM and the average score of the ReCiPe Endpoint was 461 mPt per kg FPCM. Methane enteric emissions and the use of imported soybean meal were identified as the main environmental hotspots.