A thematic review of life cycle assessment (LCA) applied to pig production

•An extensive review of LCA applied to pig production is provided chronologically over the past decade.•Individual studies have been categorised into feed, whole-system pig production and waste management themes.•We consider how LCAs have addressed state-of-the-art pig husbandry.•We offer a discussion on key findings, limitations and future research.

Commercial livestock production is known to have significant impacts on the environment. Pig production is a complex system which involves the production of animal feed, transportation, animal rearing and waste management. One tool for assessing the environmental performance of such complex systems is life cycle assessment (LCA). LCA has been applied to pig production considerably to date. This paper provides a chronological review of state-of-the-art pig production LCAs under three themes: feed production; entire-system livestock rearing; and waste management. The study considers how LCA applications have addressed technological improvements in animal husbandry, and highlights methodological limitations, particularly related to cross-study comparisons. Recent research demonstrates crude protein reduction in feed and anaerobic treatment of pig excreta resulting in bioenergy production are the key targets for environmental performance improvements related to pig production.