Sustainability assessment of chicken meat production

Abstract

As the global appetite for chicken meat grows, the competition for scarce land, water and other natural resources intensifies, whilst virtually all aspects of the environment are adversely affected. There is also increasing public concern over the standards of farm animal welfare. Hence, the aim of this thesis was to assess the sustainability of the poultry industry, identify its future challenges and evaluate potential solutions. Artificial selection of chickens for commercial objectives has been employed at an unprecedented magnitude over recent decades. In terms of sustainability, feed provision represents the poultry industry's biggest challenge. Thus, understanding the interactions between genetic change and energy use efficiency was necessary to quantifying the industry’s future impacts. Modern chickens reach slaughter weight more quickly than in the past and therefore less energy overall is used in metabolic processes. However, continuing artificial selection for efficiency will be subject to both biological limits and animal welfare concerns. Using an analytical energy flow modelling approach, the potential genetic improvement in energy use efficiency was shown to be small relative to past progress. To understand fully the environmental impacts of the poultry industry, a holistic diet formulation methodology was developed, which employed both Life Cycle Assessment (LCA) and linear programming to account for environmental burdens and bird nutritional requirements. Europe presented much opportunity to reduce the environmental impacts associated with the poultry industry via changing the formulation of the feed. Both conventional and novel ingredients were considered; the latter presented enormous potential for use as alternatives to conventional feed protein sources, mitigating the increased environmental burdens inherent in transitioning towards a high welfare chicken meat production system in the future. Finally, an innovative methodology that can account for bird welfare within a social LCA framework was developed. By applying this methodology, an association was found between the number of birds reared together in a building and the negative welfare impacts related to chicken meat production in Europe. The methodologies developed in this thesis facilitate the development of sustainable feeding strategies and animal management choices for future livestock production systems.