This collection features five peer-reviewed literature reviews on the environmental impact of livestock production.The first chapter discusses life cycle assessment (LCA) and its role in evaluating the environmental footprint of farming systems. The chapter also explores how the practical trade-off between feasibility and scientific rigour should be addressed in the field of ruminant production systems. The second chapter explores some of the many facets of livestock's contributions to climate change and the difficulties involved in quantifying them, with a closer look into the contribution of livestock methane emissions to changing atmospheric methane concentrations over the last few decades.The third chapter presents a review of the environmental sustainability impacts of swine production, focused at the farm level because the majority of environmental impacts occur by this stage of the supply chain.The fourth chapter considers the potential strategies that can be implemented to improve the environmental performance of intensive poultry systems.The final chapter examines how LCA can be used as a tool to quantify multiple resource use and environmental impacts. The chapter details how potentially harmful emissions can be assessed and measured at each stage in the life cycle of sheep products.

Chapter 1 - Assessing the environmental impact of ruminant production systems: Taro Takahashi, Rothamsted Research and University of Bristol, UK; Graham A. McAuliffe, Rothamsted Research, UK; and Michael R. F. Lee, Rothamsted Research and University of Bristol, UK; 1 Introduction 2 LCA applied to ruminant production systems 3 Case study: materials and methods 4 Case study: results and discussion 5 Conclusion 6 Acknowledgements 7 Where to look for further information 8 References Chapter 2 - Quantifying the role of livestock in climate change: Julie Wolf, USDA-ARS, USA; 1 Introduction 2 Changes in the extent, management, and efficiency of the livestock sector 3 Livestock methane, global atmospheric concentrations, and the global methane cycle 4 Quantifying enteric fermentation and manure management methane emissions 5 Broader assessments and considerations 6 Case study: evaluating livestock's contributions to global methane concentrations 7 Conclusions 8 Where to look for further information 9 References Chapter 3 - Assessing the environmental impact of swine production: G. J. Thoma, University of Arkansas, USA; 1 Introduction 2 Environmental emissions and impacts at farm level: GHG emissions 3 Environmental emissions and impacts at farm level: emissions to water and air 4 Environmental emissions and impacts at farm level: pathogenic microbes, antibiotic resistance and pharmaceuticals 5 Environmental emissions throughout the life cycle 6 Case studies 7 Summary and future trends 8 Where to look for further information 9 References Chapter 4 - Life cycle assessment (LCA) of intensive poultry production systems: Ilkka Leinonen, Newcastle University, UK; 1 Introduction 2 Life cycle assessment (LCA) of poultry production: general principles 3 The main environmental impacts of intensive poultry production 4 Reducing environmental impacts: feed consumption and composition 5 Reducing environmental impacts: breeding, housing and manure management 6 Summary 7 Future trends 8 Where to look for further information 9 References Chapter 5 - Assessing the environmental impact of sheep production: S. F. Ledgard, AgResearch Ruakura Research Centre, New Zealand; 1 Introduction 2 Environmental emissions and impacts at farm level 3 Environmental emissions throughout the life cycle 4 Case study: sheep production in France and NZ 5 Summary and future trends 6 Where to look for further information 7 References