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

PARALLEL SESSION 3C: SHEEP AND DAIRY PRODUCTION SYSTEMS 8 th Int. Conference on LCA in the
Agri-Food Sector, 1-4 Oct 2012
Table 1. Technical description of the lamb production systems studied.
Technical parameters
France “In-shed” France “Grass” New Zealand “Grass”
Number of survey farms 85 19 151
Main characteristics Significant use of hous- Significant use of peren- Significant use of pereningnial
grasslands
nial grasslands
Mixed (M) or specialised (S) S S M
Average effective area (ha) 102 114 430
% of grassland in the area (%) 63% 88% 100%
Number of ewes / farm (head) 555 670 2000
Ewe productivity (lambs weaned /
ewe/year)
1.35 1.19 1.21
Kg concentrate fed / ewe / year 210 145 0
Time of grazing (days / year) 205 280 365
2.2. Environmental assessment
The system boundary of the study covered the production of lamb from cradle-to-farm-gate. The functional
unit is one kg of total sheep live weight exiting the farm gate. Capital, medicines and cleaning products
were not included.
Each system was analysed using a methodology developed to fit its own country. Those methodologies
are described respectively in the GES’TIM guidebook (Gac et al., 2010) for France and by Ledgard et al.,
(2010) for New Zealand. Table 2 lists the models used for each source of emissions, occurring on-farm and
off-farm, as well as the atmospheric carbon stored by soil under pastures and hedges for France (as an assumption
of the compensation of emissions). The impact on climate change was assessed by using the 100year
global warming potentials proposed by IPCC (2007).
To ensure comparability of the results, a common mass allocation was firstly used to allocate impacts between
meat and wool, the two co-products of the sheep production systems.
Table 2. Sources of emissions and models used in France and New Zealand
Sources of emissions Gas France New-Zealand
Enteric fermentation CH4 Vermorel et al., 2008 Clark et al., 2007 (Tier 2)
Manure in buildings CH4, N2O GES’TIM -
Manure storage CH4, N2O GES’TIM -
Grazing CH4, N2O GES’TIM Overseer®
Nitrogen inputs - direct (fertilisers, crop residues)
and indirect (volatilisation, leaching)
N2O IPCC 2006 Overseer®
Energy use on farm (fuel combustion) CO2 GES’TIM
Inputs (e.g., feed, fertilisers, pesticides, energy CO2eq GES’TIM Ecoinvent, Ledgard et al.,
purchased)
2010, 2011
Carbon storage (pasture, hedges)
Overseer® (Wheeler et al., 2007)
CO2 Arrouays et al., 2002 -
A sensitivity analysis was performed by comparing the same methodologies across both countries, i.e.,
the New Zealand data set was analysed with the French methodology and vice versa. Effects of allocation
method were also tested, i.e., economic vs mass allocation.
3. Results
The average carbon footprint of French lamb was 12.9 kg CO2 eq/kg live weight (LW) sold (Table 3).
There was no significant difference between the average values for the two French systems (Grass 12.74 –
19 farms surveyed; In-shed 12.94 – 85 farms surveyed), but there was a high variability between farms
within each system (standard deviations of 2.9 and 2.8, respectively). The carbon footprint of the main New
Zealand system was 8.52 kg CO2 eq/kg LW.
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