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
552
Effect of ethics on integral ecological impact of organic eggs
S.E.M. Dekker 1 , I.J.M. de Boer 2 , A.J.A. Aarnink 3 , P.W.G., Groot Koerkamp 1
1 Farm Technology Group, Wageningen University, P.O. box 17, 6700 AA, Wageningen, the Netherlands
2 Animal Production Systems Group, Wageningen University, P.O. box 338, 6700 AH, Wageningen, the Netherlands
3 Wageningen UR Livestock Research, P.O. box 65, 8200 AB, Lelystad, the Netherlands
Corresponding author. E-mail: sanne.dekker@wur.nl
ABSTRACT
Organic agriculture has a specific perspective on sustainability, captured in their goal, definition and four principles of organic agriculture
and resulting certification (IFOAM, 2012). We refer to this perspective as the organic-ethical framework. For organic egg
production, this framework implies three main requirements: (1) loose hen housing, (2) outdoor access, and (3) limited use of external
resources, i.e. artificial fertilisers, pesticides, herbicides, genetically modified organisms, and medication. Our research objective
was to assess the effect of these three requirements on the integral ecological impact of Dutch organic egg production. We approached
this objective in three steps. In step 1 we compared life cycle assessment (LCA) results of egg production with and without
an organic ethical framework. In step 2 we identified main ecological issues of current Dutch organic egg production by means of
LCA. In step 3 we explored options to reduce integral ecological impact of Dutch organic egg production within the boundaries of
the organic ethical framework, i.e. replace single-tiered with multi-tiered loose hen housing and replace imported with regional diet
ingredients.
Comparison of battery cage with barn egg production shows that the requirement of loose hen housing results in a 12% to 176%
higher impact for the ecological issues studied, except for phosphorus (P) deficit which was equal (Table 1). This higher impact is
mainly explained by a higher conversion of feed to eggs of loose housed hens (2.33 kg feed kg -1 egg) compared with hens in battery
cages (1.99 kg feed kg -1 egg) (Dekker et al., 2011b). A second reason for the higher acidification potential of loose hen housing was
that reduction of ammonia emission by drying and removal of manure in loose laying hen houses is problematic. Comparison of barn
with free range egg production shows that the requirement of access to an outdoor run results in a relative small, i.e. 0% to 10%,
increase of the ecological impact (Table 1). Comparison of free range and organic egg production shows that the requirement of
limited use of external resources results in a 10% lower global warming potential, a 15% lower energy use, a 93% lower fossil P use,
a 108% lower nitrogen (N) surplus and a 114% lower P surplus, but a 82% higher land occupation, a 68% higher acidification potential,
a 1767% higher N surplus and a 900% higher P deficit (Table 1). We found that differences in the ecological impact of egg
production systems with and without limited use of external resources resulted mainly from differences in type and amount of fertilisation
and conversion of feed to eggs. Multi-tiered housing to dry and remove manure (mitigation housing in Table 1; Dekker et al.,
2011a) and production of diet ingredients and eggs in the same region to assure availability of manure and increase yields (mitigation
diet in Table 1; Dekker et al., 2012b), have potential to reduce the ecological impact of organic egg production within the ethical
boundaries of organic egg production. If these mitigation options are applied we predict a lower energy use, fossil P use, N surplus
and P surplus, but a higher global warming potential, land occupation, acidification potential, N deficit and P deficit for organic
compared with battery cage egg production.
We conclude that increases of the ecological impact caused by the organic ethical framework mainly result from inefficient N and P
management and inefficient conversion of feed to eggs. Issues in the current egg production chain regarding manure management
are: (1) a lack of regionally available manure (Dekker et al., 2011b), (2) unbalanced application and N-P ratios of manure fertiliser,
(3) high N-emissions from faeces in loose housing systems, and (4) loss of N and P from manure in the outdoor run (Dekker et al.,
2011b; Dekker et al., 2012a). The higher conversion of feed to eggs may be caused by: (1) a higher body mass of loose housed hens,
(2) increased freedom of movement, (3) prohibited use of external resources, caused by a worse amino acid profile of the diet, (4)
limited use of medication, and (5) a smaller number of hens per m 2 in the hen house, which generally results in a lower indoor temperature
(Van Knegsel and van Krimpen, 2008; Dekker et al., 2012b; Dekker et al., 2011a). Research is required to determine
whether inefficient N and P management and inefficient conversion of feed to eggs in organic egg production must be accepted as an
implication of the organic ethical framework or can be further reduced within the boundaries of the organic ethical framework.