On-farm quantification of sustainability indicators: an application to egg production systems.

1. On-farm quantification of sustainability indicators (SI) is an effective way to make sustainable development measurable. The egg production sector was used as a case study to illustrate this approach. 2. The objective was to select SI for economic, ecological and societal issues, and to analyse the performance on selected SI of different production systems. 3. For the case study, we compared 4 egg production systems, characterised by differences in the housing systems which are most common in the Netherlands: the battery-cage system, the deep-litter system with and without outdoor run, and the aviary system with outdoor run. 4. Based on a clear set of criteria, we selected SI for animal welfare, economics, environmental impact, ergonomics and product quality. 5. We showed that on-farm quantification of SI was an appropriate method to identify the strengths and weaknesses of different systems. 6. From this analysis it appears that the aviary system with outdoor run is a good alternative for the battery-cage system, with better scores for the aviary system on animal welfare and economics, but with worse scores on environmental impact.