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
Given data availability limitations on agricultural land uses and growing seasons in the same year, no allocation
among different types of agricultural production (crop rotations) was established. Allocation between
milk and meat was done based on the quantity of feed required to make milk and meat, as feeds have
different available energies for growth and lactation. Other co-products allocations include soybean and soybean
meal, corn grain and dried distillers grains with solubles (DDGS).
To perform land use impact assessment related to feed production, feed mix in the rations and crop production
data were collected. Average rations (in kg dry matter / kg FPCM) that were identified in the Milk
carbon footprint study (Thoma et al., 2010) and calculated for each of all five major dairy productions regions
were considered. In addition, annual data on crop production and area harvested were collected at the
state level for each feed component from the United States Department of Agriculture (USDA) and National
Agricultural Statistics Service (NASS) (USDA NASS, 2010). These parameters were also used to calculate
the corresponding annual yields of production.
Eleven main feed components were considered in the ration, including:
commodity crops that are traded and shipped on national scale markets are assumed to be produced
in any state
domestic crops such as light forage and haylage are assumed to be produced within a region (out
of the five defined regions) where the farm is located
pasture and local crops that are heavy or not transportable feed are assumed to be grown locally
on-farm
Table 1 shows the different feed supply mix models that were assumed for a spatial impact assessment related
to feed production.
Table 1. Supply mix models for each feed components
Supply mix models Feed components
National, based on inter stated transport data DDGS dry
DDGS wet
Corn grain
Soybean
Soybean meal
State Alfalfa silage
Corn silage
Grass pasture
Grass silage
Regional Alfalfa hay
Grass hay
2.2. Life Cycle Impact Assessment
From a life cycle impact assessment (LCIA) perspective, the method used is built upon recommendations
of previously published works as well as the framework and the principles established by the UNEP/SETAC
Life Cycle Initiative Task Force on Land Use LCIA phase 1 (Milà i Canals et al., 2007) and phase 2 (LUL-
CIA, 2008-2012). Unlike traditional categories that assess impacts of emissions, land use impact characterisation
is not structured according to the conventional steps of fate, exposure and effect, nor is it based on
mass and energy balance. Rather, the assessment stems from the change in environmental quality (EQ) induced
by land use over time (Fig. 1).
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Figure 1. Environmental quality curve (adapted from Milà i Canals et al., (2007), Saad et al., (2011))