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
2.1. Goal and Scope
Axtra XAP increases the digestibility of the feed thereby increasing the broiler’s utilisation of the nutrients
in the feed. When Axtra XAP is used in the feed formulation it is possible to include a higher amount of
cheaper feed ingredients that have a lower nutritional value without compromising the growth of the broiler.
The study strived to assess the changes in GHG emissions when a broiler was reared using a feed formulation
without Axtra XAP compared to when a broiler was reared using a feed formulation with Axtra XAP.
The functional unit applied in the study was the production of one kg live broiler, assuming that the production
of one kg live broiler meat required 1.8 kg feed. The two feed formulations represented US commercial
examples in 2011. In terms of life cycle impact assessment, the study addresses GHG emissions based on the
IPPC 2007 GWP 100a impact method. As the nature of the LCA was comparative (comparing two scenarios),
identical life cycle stages and processes in the two scenarios were omitted. Axtra XAP facilitated an
increase in the digestibility of the feed, resulting in changes in the feed formulation and the manure emitted
by the broiler. Changes in the manure resulted in changed methane and nitrogen oxide emissions from the
manure and therefore changes in the end use of the manure.
2.2. Feed formulations
The effect of using Axtra XAP was analysed in eight feed trials made in collaboration with research institutions
in different parts of the world (Danisco, no data). Between 144 and 1800 broilers were included in
each feed trial. The results showed a reduction in the feed used to rear the same amount of broiler meat of
3.8% to 8.7%, depending on the feed formulation. The results of the feed trials were incorporated into the
computer software used to formulate the two feed formulations. The feed formulations used in scenario one
and scenario two are presented in table 1 and follow Dupont, Danisco Animal Nutrition’s recommendations
for using the Axtra XAP product.
Table 1. Feed formulations provided by DuPont, Danisco Animal Nutrition
Raw materials Scenario one feed composition Scenario two feed composition
without Axtra XAP (g)
with Axtra XAP (g)
Corn 1,171.8 1,162.9
DDGS 180.0 216.0
Phyzyme XP 0.4 0.4
Soya bean meal 347.2 334.3
Meat and bone meal 52.9 35.4
L-Lysine (HCL) 5.7 6.3
DL-Methionine 4.2 4.2
NaCL 6.0 7.0
Limestone 15.2 19.9
Dicalcium phosphate 1.4 5.1
Vitamins/ Minerals 1.8 1.8
Axtra XAP 102 TPT 0 0.9
Pig and poultry fats 11.9 4.5
L-threonine 1.5 1.3
Total 1,800 1,800
The improvement in digestibility and performance obtained by applying Axtra XAP was used to reduce
the amount of corn, soybean meal, meat and bone meal, and pig and poultry fats in the diet and to increase
the amount of dried distillers grains with solubles (DDGS) in the feed. This provided an economic benefit of
4.04 $ per ton of feed in scenario two compared to scenario one. A minimum level of fat is required in the
feed formulation to ensure pellet quality, therefore, it was not possible to apply the full Axtra XAP recommendations
for energy reduction in the feed formulation. Hence, in scenario two there is an excess amount of
energy provided by the enzyme (48 kcal per kg feed) compared to scenario one. The excess energy is not
accounted for in the study and the LCA therefore represents a conservative estimate of Axtra XAP’s potential.
3. Results
3.1 Life Cycle Inventory
Figure 1 provides an overview of the system boundary including marginal mechanisms. Corn was not
considered a constraint product and it was modelled as corn produced in the US, based on data from Dal-
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