Abstract: Given the large-scale and intensive development of the livestock industry, attention has become focused on centralized disposal of livestock waste and efficient utilization of biomass resources. To assess the environmental impact of large-scale multi-floor pig farming systems (LMPFSs), the life cycle assessment method was used to analyze the resource, and energy consumption, and environmental impact of the entire process of feed production, pig breeding, and manure treatment of an LMPFS, and the comprehensive benefits of an LMPFS were compared with those of a traditional pig farming system. Results show that in terms of the environmental impact index of each subsystem, manure disposal and resource utilization each accounted for nearly half of the total, whereas feed production, pig breeding, and other subsystems accounted for 60.36%, 24.25%, and 15.39% of the total, respectively. In relation to global warming, the contributions of pig farming and manure treatment subsystems converged, accounting for 32.95% and 44.98%, respectively. Among the contributions to acidification and eutrophication, the manure disposal and resource utilization subsystems contributed the most, accounting for 58.59% and 63.78%, respectively. In terms of energy consumption, the feed production subsystem accounted for 79.58%. In comparison with a traditional pig farming system, the greenhouse gas emissions, area of breeding land, and human resources associated with an LMPFS were reduced by 30.30%, 91.00%, and 72.00%, respectively.

Key words: biomass, multi-floor pig farming, life cycle assessment (LCA), environmental impact, comprehensive benefit