Charles Debouche

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.

FLOW RATE QUALITY OF NEW FLAT FAN NOZZLES

Manufacturers of spraying nozzles have established manufacturing tolerances to guarantee the quality of their products. They control, among other things, the new nozzles’ flow rate by comparison with the nominal flow rate. When the deviation exceeds a set limit, the nozzles are rejected. A survey carried out among three manufacturers made it possible to determine the manufacturing tolerances and limits that manufacturers impose upon themselves. The flow rates of 1565 new nozzles collected on the market from these manufacturers were measured on a device developed for this study. Different statistical tests assessed the performances and characteristics of the products. The quality standards announced by the manufacturers were not checked for every nozzle. On average, 20% of the new nozzles exceeded the manufacturing tolerances. The average flow rate of the nozzle sets equaled the nominal flow rate. In practice, the probability distribution of the flow rate of new nozzles should be normal. The dispersion of the new nozzle flow rates was slightly higher than the theoretical one. The quality of the products differed from one manufacturer to another.