Assessment of the potential of digestibility-improving enzymes to reduce greenhouse gas emissions from broiler production

The objective of this study was to examine the potential of digestibility-improving enzymes to reduce greenhouse gas (GHG) emissions from commercial broiler production. The enzyme product which was examined is a combination of xylanase (X), α-amylase (A), and protease (P) developed by Danisco Animal Nutrition (DuPont Industrial Biosciences). XAP facilitates higher inclusion rates in the diet of cheaper and possibly more environmentally friendly feed ingredients that have a lower nutritional value. XAP can be used for corn-soybean based diets comprising up to 12% by-products. Two scenarios were compared: one included XAP whereas the other scenario did not include XAP. The potential of XAP to reduce GHG emissions was documented through a GHG assessment based on Life Cycle Assessment principles. Consequential modelling was applied including indirect land use changes (ILUC) and direct land use (LU). The findings showed that XAP facilitated savings in GHG emissions from broiler production in the order of 90 g CO2 eq. per FU. It corresponded to a 5-9% reduction of GHG emissions from broiler production. The sensitivity analysis showed that the results varied substantially, but in all analyses the GHG emissions were reduced. The two most important parameters were: assumptions about the actual changes in the feed formulation and the modelling of ILUC. The two parameters can significantly influence the estimated improvement potential.