Effect of origin and composition of diet on ecological impact of the organic egg production chain

Replacement of Ukrainian wheat with Dutch triticale, and of Brazilian soybeans, Italian sunflower seed expeller and German peas with Dutch rapeseed expeller reduced the integral ecological impact compared with current organic egg production. Simultaneous replacement of these ingredients (scenario MU) resulted in an overall lower and more balanced reduction of the different ecological impacts (41-101%) than single replacement of these ingredients (41-215%). Compared with B ecological impact of scenario MU decreased for global warming potential (91%), energy use (79%), land occupation (68%), acidification potential (99%), N deficit (85%), P deficit (41%) and P surplus (81%), but slightly increased for N surplus (101%). The low ecological impact of MU was explained by (1) a relative small increase in feed conversion ratio (from 2.32 for B to 2.37 for MU), (2) a reduction of the transport distance of 44.4% of the diet ingredients, (3) replacement of the currently used crops with crops that have a higher yield in combination with a balanced applied amount of N and P in manure, and (4) use of expeller instead of whole ingredients.