Reduction of greenhouse gas emissions from feed supply chains by utilizing regionally produced protein sources: the case of Austrian dairy production.

Background: The aim of this study was to analyse the potential greenhouse gas emissions (GHGE) for regionally alternative produced protein-rich feedstuffs (APRFs) which are utilized for dairy cattle in Austria in comparison to solvent-extracted soybean meal (SBME). In addition to GHGE from agriculture and related upstream supply chains, the effects of land use change were calculated and were included in the results for GHGE. Furthermore, mixtures of APRFs were evaluated which provided energy and utilizable protein equivalent to SBME.

Results: Highest GHGE were estimated for SBME, mainly due to land use change-related emissions. Medium GHGE were found for distillers' dried grains with solubles, for seed cake and solvent-extracted meal from rapeseed and for lucerne cobs. Cake and solvent-extracted meal from sunflower seed as well as faba beans were loaded with lowest GHGE. Substituting SBME by nutritionally equivalent mixtures of APRFs, on average, resulted in a reduction of GHGE of 42% (22-62%).

Conclusion: Utilization of locally produced APRFs shows clear advantages in terms of GHGE. Balanced mixtures of APRFs may offer specific benefits, as they allow for a combination of desirable nutritional value and reduced GHGE.