Conventional versus alternative pig production assessed by multicriteria decision analysis

Differentiated quality and respect for the environment seem to be linked implicitly, but there is no demonstration of this concept for pig production. Pig production takes on different forms. Conventional pig production occurs side by side with some productions of " differentiated qualities" that are encouraged by the European Union as well as by nations. At the same time, the EU and nations are imposing environmental limitations concerning, for instance, the management of nitrogen and respect for neighbours. Here, we compared environmental impacts of 3 types of production: conventional production, organic production and free- range production. We took into account the process performances of 21 farms in the Walloon Region, Belgium. We compared the global process performances by multicriteria analysis. A jury of 16 experts was questioned to assign a relative importance to the emissions of ammonia, greenhouse gases, molecular nitrogen, odour and nitrogen to effluents. We found that the highest weighting was assigned to the N content of effluents, then to odour diffusion, the emission of ammonia, the emissions of greenhouse gas and finally, the emission of molecular nitrogen got a weak weighting. Our results showed that the relative ordering obtained was: ( 1) free- range production, ( 2) organic production and ( 3) conventional production. Nevertheless, within every sample a significant variability in the performances was observed. The same method applied within every sample enabled the creation of sub- groups. After reordering, we found that the most effective farms of every system of production were classified as top of the class. Thus, our original approach showed that on average the production of differentiated qualities was more environmentally effective than the conventional production. However, the variability of the performances within a system of production was high and it was quite possible for the conventional farms to reach results comparable with those of the best organic and free- range operations.