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

PARALLEL SESSION 2C: QUANTIFICATION AND REDUCTION OF UNCERTAINTY 8 th Int. Conference on LCA in the
Agri-Food Sector, 1-4 Oct 2012
198
Quantifying environmental impacts and their uncertainties for UK
broiler and egg production systems
Ilkka Leinonen 1,* , Adrian Williams 2 , Ilias Kyriazakis 1
1 School of Agriculture, Food and Rural Development, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
2 School of Applied Sciences, Cranfield University, Bedford, MK43 0AL, UK
Corresponding author. E-mail: ilkka.leinonen@newcastle.ac.uk
ABSTRACT
The environmental burdens of the main UK broiler and egg production systems were quantified using a systems modelling approach
with Monte Carlo simulations for statistical analyses. Feed was the main component of the global warming potential in all broiler and
egg systems. Manure was a major source of acidification and eutrophication potentials. The length of the production cycle was lowest
in the standard indoor broiler system, and therefore the feed consumption and manure production were also lowest. This caused
statistically significant differences in most of the impact categories between the broiler systems. The number of birds required to
produce equal amount of eggs, and the amount of feed consumed per bird were highest in organic and lowest in the cage system.
These general differences in productivity affected the environmental impacts of the different egg systems, although in some impact
categories the differences were not always significant.
Keywords: broiler, egg, uncertainty analysis, global warming potential, energy use
1. Introduction
UK poultry production, including broilers and eggs, has been identified as being relatively environmentally-efficient,
per unit weight, compared to the production of other animal commodities (Williams et al.,
2006). However, like all agricultural systems, any current poultry system has scope to improve, and thus has
the potential to reduce its environmental impacts. For example, with an annual production of 8862 million
eggs (about 0.4 billion kg) produced in the UK (Defra, 2009) and 61 billion kg produced worldwide annually
(FAO, 2011), the egg laying systems are likely to be significant contributors to both resource use and environmental
burdens, and therefore have also potential for large scale reduction of impacts such as greenhouse
gas emissions.
The aim of the current study was to apply the LCA method “from cradle to farm gate”, to quantify the environmental
burdens of the main broiler and egg production systems in the UK, and hence to identify the
main opportunities to reduce these impacts within each system. The broiler systems included in the study
were 1) standard indoor, 2) free range and 3) organic production. According to the Defra (2007) statistics,
the total broiler chicken populations in these systems in the UK were 101, 4.4 and 1.8 million, respectively.
The egg production systems considered in this study were 1) conventional cage, 2) barn, 3) free range and 4)
organic laying. Although the egg production in conventional cages has been banned by the EU and is not
used in the UK anymore, it is still in use in some other European countries, and therefore the results for the
cage laying system are also presented in this study. Results for enriched cages now used in the UK are expected
to be broadly similar.
2. Methods
2.1. Systems approach and data
The general approach taken in the current study was with systems modelling of production. This included
structural models of the industry, process models and simulation models that were unified in the systems
approach so that changes in one area caused consistent interactions elsewhere. This approach was applied to
both feed crop and animal production. The systems modelled in this study included crop production, noncrop
nutrient production, feed processing, breeding, broiler production, pullet rearing, egg laying and manure
and general waste management, as described by Williams et al., (2006) and Leinonen et al., (2012a;b). All
modelled animal production systems included farm energy, feed and water use and gaseous emissions from
housing.
The production systems in this study were considered to represent typical UK egg and broiler production
(Table 1, Table 2) as described by Leinonen et al., (2012a;b). The farm energy consumption for heating,
lighting, ventilation, feeding and incineration of dead birds was based on average data from typical farms as
provided by the industry. Information about the type and amount of bedding was also obtained from the industry.
Additional data, such as LCI of agricultural buildings and machinery, came from Williams et al.,
(2006).