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

摘要

The objective of this research was to assess the potential to reduce the integral ecological impact (i.e. impact along the egg production chain per kg egg) of Dutch organic egg production by replacing currently used imported diet ingredients with Dutch diet ingredients. We realized this objective by comparing the life cycle assessments (LCA) of current Dutch organic egg production, i.e. base situation (B) with different scenarios. In each scenario, one imported diet ingredient was replaced with a diet ingredient produced in the Netherlands. Finally, we formulated a scenario in which several ingredients, that individually resulted in the lowest mean change in ecological impact along the organic egg production chain, were replaced simultaneously. We included differences between production chains in cultivation (i.e. field operation, manure application and yield), transport, feed intake, egg production and N excretion. 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