LCA Food 2012 in Saint Malo, France! - Manifestations et colloques ...

PARALLEL SESSION 6C: POULTRY AND PORK PRODUCTION SYSTEMS 8 th Int. Conference on LCA in the
Agri-Food Sector, 1-4 Oct 2012
fertiliser then less inorganic nitrogen fertiliser was displaced, resulting in an increase in GHG emissions of
9.1 g CO2 eq. per FU.
3.3 Sensitivity analysis
In the sensitivity analysis the effects from changes in the feed formulation, the exclusion of ILUC,
changes in the marginal use of rendered fats and greases and the impact from the production of soybean meal
were examined. The most significant parameters proved to be changes in the feed formulations and the exclusion
of ILUC. As mentioned earlier, it was not possible to apply the full benefits of Axtra XAP in scenario
two. Therefore, two additional feed formulations were made, one without Axtra XAP and one with
Axtra XAP, where no restrictions were made on the fat content, allowing for the full benefits of Axtra XAP
to be applied. Changes in the feed formulations resulted in almost a tripling (281%) of the savings in GHG
emissions indicating that either the feed formulations were too conservative or there is a large unutilised
potential for further improvement. The exclusion of ILUC resulted in a reduction in the savings in GHG
emissions of 93% compared to the reference scenario. It must be concluded that there are considerable uncertainties
connected with both the methodological choices made and the data collection.
4. Discussion
To evaluate the savings facilitated by Axtra XAP it was compared to the total GHG emissions from the
production of broiler meat. In total four studies were examined: LCA food (2003), Cederberg (2009), Williams
et al., (2009) and Nielsen et al., (2011). The results from these studies varied considerably from approximately
1.9 kg CO2 per kg bone free meat in Cederberg (2009) to approximately 3.4 kg CO2 per kg bone
free meat in Williams et al., (2009), assessing that the carcass weight made up 70% of live weight and bone
free meat made up 77% of the carcass weight. To make a conservative estimate of Axtra XAP’s improvement
potential the highest GHG emissions from the studies reviewed was used. The calculations showed that
savings in GHG emissions facilitated by Axtra XAP amounted to 4.9% per kg bone free broiler meat. In
2010, the total production of chicken meat was 86,064 million ton (FAO, 2011), thus Axtra XAP could potentially
facilitate savings in GHG emissions of roughly 14 million ton CO2 eq. This assumed that all producers
used the same feed formulation, applied Axtra XAP to their diets and that digestibility improving
enzymes were not already used in the diets. The results should however be applied on a global scale with
caution, as consequential modelling accounts for marginal changes, and does not represent what will happen
on the market if all broiler producers changed their feed formulation. Additionally, the savings in GHG
emissions will depend on the prices of the raw ingredients, as the feed formulations are made including only
consideration to the price and the nutritional value of the feed. As documented in the sensitivity analysis, the
feed formulation was one of the most important parameters when determining Axtra XAP’s potential. Thus,
the savings facilitated by Axtra XAP could potentially change considerably depending on the feed prices.
Furthermore, Axtra XAP will reduce production cost and most likely reduce the price of broiler meat, potentially
resulting in an increasing consumption of broiler meat (rebound effect).
5. Conclusion
Axtra XAP facilitated savings in GHG emissions of 90.5 g CO2 eq. per FU. Comparing the potential savings
in GHG emission documented in the present LCA, with the total greenhouse gas emissions from the
production of one kg bone free broiler meat documented in Williams et al., (2009), showed that Axtra XAP
had the potential to reduce the impact from broiler rearing by 5% resulting in a global potential saving of 14
million ton CO2 eq. each year. The results of the sensitivity analysis showed that the most significant parameters
were the inclusion or exclusion of ILUC and changes in the feed formulation. However, all sensitivity
analysis resulted in a reduction in the GHG emissions when Axtra XAP was included in the feed formulation
compared to when it was not.
6. References
Barletta, A., 2011. Introduction: Current market and expected developments, in Bedford, M.R., Partridge G.G. (Eds), Enzymes in
Farm Animal Nutrition, 2nd Edition, pp. 1-11, CAB International, Bodmin, UK
Cederberg, C., Sonesson, U., Henriksson, M., Sund, V., Davis J., 2009. Greenhouse gas emissions from Swedish production of milk
and eggs 1990 and 2005. http://www.sik.se/archive/pdf-filer-katalog/sr793.pdf. (accessed 29.12.11)
Dalgaard, R., Schmidt, J., Halberg, N., Christensen, P., Thrane, M. and Pengue, W.A., 2008. LCA of Soybean Meals. Int J LCA 13
(3) 240-254.
Dalgaard, R., 2011. Inventory of key feedstock. Developed by Randi Dalgaard, 2.0 LCA consultant, Denmark. Available on request
(mthr@danisco.com)
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