Trade And Environmental Impacts Of Animal Welfare: A Partial Equilibrium Approach

Published on 22 January 2010 in Food, health and wellbeing

Pig in straw


This research analyses the impacts of a scientific advance that improves animal welfare, upon the environment and trade in Scotland using partial equilibrium (PE) modelling. The CAP reform has consistently strengthened the role of environment and animal welfare issues in the European Union, however there are still concerns about their impact on trade under the WTO rules.

Any approach to assess animal welfare and the creation of strategies, policies and standards must involve a multidisciplinary approach dealing with aspects of production, livestock sciences, legislation, trade and environment. While there has been work done on modelling linkages between animal welfare and trade or between animal welfare and the environment, there has been nothing done yet to simultaneously model all three despite the increasing need to harmonise environmental and animal welfare standards for imports with those faced by domestic producers in ways compatible with WTO rules.

Key Points

Our model simulates the effects of animal welfare changes (i.e., improvement in the pig neonatal survival through improved (high fibre) sow diets used before mating) on the pig production systems (pig meat) and further on trade flows (trade in pig meat) and environment (water and air pollution).

We consider two animal welfare simulation scenarios, namely the status quo – no animal welfare change as regards pig neonatal mortality (baseline scenario) and the case of improving pig neonatal survival (alternative scenario) and compare the impacts on trade and environment between the two scenarios during the simulation horizon 2008-2015. The results show that the increase in animal welfare has a lower impact on the environment in the alternative scenario compared to the baseline scenario (by about 6% at the end of the simulation horizon) and a positive impact on net trade in the alternative scenario compared to the baseline scenario (by about 13% at the end of the simulation horizon) (Toma et al., 2008; Ashworth et al., 2009).

Research Undertaken

The PE approach models a baseline scenario (equilibrium between demand and supply for pig meat), adds shocks (changes in animal welfare) and sees how the system responds (shifts in prices, quantities, trade and environment). PE models are useful for understanding a particular response to changing policy scenarios and can capture the impacts of small changes that do not (seriously) affect sectors other than agriculture.

The model has three modules, 'production and trade', 'environment' and 'animal welfare'. As regards the 'production and trade' part of the model, we employ a similar approach to other commodity trade partial equilibrium models used for policy evaluation and adapted for the specific case of a pig farm. As regards the environmental module of the model, we associate the pollution to the use of production inputs, namely link the use of nitrogen inputs (e.g., nitrogenous fertilisers, manure) to nitrogen loss through leaching/runoff into groundwater (nitrates) and greenhouse gases (emissions of nitrous oxide and methane). We measure the impact of animal welfare changes on trade and environment indirectly through production. 

Model Diagram

Model diagram

Policy Implications

The research offers a means to address the externalities of animal welfare, that is, its impacts beyond the farm gate on trade and the environment. It provides policy relevant information and an improved understanding of the interactions between economic and environmental/climate change values and animal welfare in the context of CAP reform.

The Scottish Government Rural and Environmental Research and Analysis Directorate is gratefully acknowledged for supporting this work. Studies assessing the effects of a high fibre diet on litter size were funded by DEFRA, Meat and Livestock Commission and JSR Farms Ltd., as part of the LINK Sustainable Livestock Production Programme.


Luiza Toma (SAC), Cheryl J Ashworth (Roslin Institute), Alistair W. Stott (SAC)


Food, health and wellbeing

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