Life cycle environmental and economic impact assessment of pollution mitigation strategies implemented in European pig production systems

Abstract

Pig production systems are significant contributors to environmental impacts arising from livestock and with the increasing demand for pork meat, their environmental footprint cannot be neglected. Many emerging technologies and alternative farm management practices have the potential to improve their environmental performance. However, the implementation of such practices is not always economically viable. Furthermore, their pollution mitigation potential can be sensitive to climate change and geographic variability. The aim of this thesis was to develop a whole-farm environmental abatement cost framework, able to evaluate the environmental and economic performance of pollution mitigation strategies from a life cycle perspective, while accounting for interactions between system components, climate change and spatial variability. To fully understand and evaluate the environmental impacts associated with European pig production, a whole-farm, environmental Life Cycle Assessment (LCA) was developed on a typical Danish, integrated pig farming system. Through this model, potential environmental impact hotspots were identified related to pig housing and manure management. The abatement potential of a range of housing and manure management related pollution mitigation strategies was then evaluated. The results of this analysis showed that anaerobic digestion of slurry and in-house slurry acidification can significantly reduce the system environmental impact for a great range of impact categories. Farm profitability was then evaluated through scenarios that simulated the implementation of the proposed pollution mitigation strategies, to determine their cost-effectiveness as stand-alone investments and through their combined implementation. For this purpose, an environmental abatement cost framework was developed by integrating the environmental LCA with a whole-farm economic model that considered capital costs, operating costs and all potential revenue streams. Anaerobic digestion of slurry was the most cost-effective strategy overall, achieving great environmental impact reductions while generating revenue and therefore increasing farm profitability. The environmental abatement cost framework was then used to investigate the mitigation potential of two pig-cooling strategies that aim for ammonia emission reductions in a Swedish pig-fattening unit. Moreover, the framework was integrated with data on projected climate change for Sweden to evaluate the resilience and cost-effectiveness of these strategies against ambient temperature

increases. Both pig-cooling methods effectively mitigated heat stress related effects on animal performance, and significantly reduce system environmental impact, while improving farm profitability even under an intermediate climate change scenario. Finally, the effects of geographic variability on the assessment of potential environmental and economic implications associated with the implementation of alternative manure management strategies in Danish pig farming systems were investigated. To achieve this, Geographical Information System (GIS) data and methods were integrated along with the environmental abatement cost framework. In doing so, spatially explicit environmental impact characterisation factors, regional policies that concern pig farming near nature-sensitive areas and agglomeration effects on the economy of the farm were taken into account. The analysis revealed significant effects of location on the cost-effectiveness of several environmental abatement strategies considered. The methodologies developed and demonstrated in this thesis have the potential to guide decision making regarding farm investments that aim to improve system sustainability in a cost-effective manner.