Evaluation of environmental sustainability of milk goat production with LCA approach

Although the contribution to greenhouse gas emissions of dairy goat breeding has a limited weight in respect to the whole livestock sector, it is yet paramount to reduce the carbon footprint in order to limit the impact on climate change. The objective of this study was to quantify the environmental impact of milk production in 8 dairy goat farms in Lombardy region (Northern Italy) by using a Life Cycle Assessment approach; the focus was set on critical points of the production process. Environmental impact results were very variable, ranging from 1.12 to 3.05 kg CO2 eq/kg fat and protein corrected milk. Farms with a different milk production level (946 and 1260 kg per goat/year) showed similar levels of kg CO2 eq emitted (1.46 vs 1.48). This suggests that the intensification of milk production alone is not enough to make the goat milk production system more efficient: in fact, appropriate feeding strategies, in particular the increase of feed self-sufficiency and a rational management of livestock effluents, can also help to reduce the emission load of goat milk production. Our study confirms that enteric methane emissions and purchased feed are the main drivers of environmental impact of goat milk production, although with a different weight of these hotspots, according to the production context. During goat cheese production, only 10% of greenhouse gas emissions depend on cheese making process per se, whereas the major impact (90%) is due to goat milk production. Farms that are characterized by extensive systems had worse environmental results expressed by kg fat and protein corrected milk; when 1 ha of usable agricultural area is considered as functional unit, these farms obtain better environmental results, because their impact is diluted on a higher soil availability. This study has highlighted that, although there are processes such as enteric methane emission in which the intervention of farmer is limited, there are management strategies that can contribute to reduce the environmental impact of goat milk production.