Using environmental constraints to formulate low-impact poultry feeds

With the aim of reducing the environmental impacts of poultry feed, a database of the impacts of feed components destined for formulation was constructed using the Life Cycle Assessment (LCA) method. We used linear programming to create least cost feed formulas for fast-growing broiler (FGB), slow-growing broiler (SGB, i.e. quality label), laying hen and for three contrasting feed-cost situations (January 2006, December 2007 and March 2009). We focused on Eutrophication Potential (EP, a regional impact) and Climate Change (CC, a global impact) which were constraints to formulate low-impact poultry feed. The effects of using these constraints on feed cost and the use of feed components were investigated for a feed production plant in Bretagne (western France). Environmental impacts of poultry feed increased with the energy and protein content of the formula and were affected by the relative costs of feed components. FGB formulas had the highest impacts, followed by formulas for SGB and laying hens. The search for a minimum level of EP and CC of the formula decreased its impacts by 1–8% and by 1–12% respectively, and increased its cost by 2–8%, depending on the type of feed and the feed-cost situation. Impact reduction was obtained by partial substitution of soybean meal and cereals by rapeseed meal, grain legumes and co-products (wheat bran, gluten). Furthermore, 70% of the potential reduction of the EP and CC impacts could be obtained at a modest (0.5–4%) increase in the cost of the formulas. Some other ways to reduce feed impacts were explored, such as taking into account the geographic origin of maize crops and adopting a modified regulatory constraint for SGB formulas. It is important to continue this study by taking into account the whole life cycle of poultry production.