Alternatives for the battery cage system: a comparison of economic, environmental and societal performance

The ban on the battery cage system in the European Union after 2012, mainly due to impaired hen welfare, forces farmers to change to alternative housing systems for laying hens. Large-scale introduction of more hen-friendly systems, however, requires a comparison of these systems on their economic, ecological and societal (EES) performance, i.e., on their contribution to sustainable development. The aim of this paper is to assess the EES performance of the battery cage system, and of the three most prevalent alternative housing systems in the Netherlands (i.e., the deep litter system with and without outdoor run, and the aviary system with outdoor run). To asses the EES performance of different egg production systems, the following indicators were quantified: labour income per full time equivalent; land and fossil energy use per kg egg produced; acidification, eutrophication and global warming per kg egg produced; animal needs index; mortality rate (21-68 wks); medicine use; deviations from the production curve; % farmers with physical complaints; % of second quality of eggs; and the Salmonella enteritidis status of the flock. In 2004, data were collected by visiting 16 farms with battery cages, 15 with a deep litter system without outdoor run, 17 with a deep litter system with outdoor run and 13 with an aviary system with outdoor run. Data were analysed statistically to reveal significant differences among production systems. Economic performance was best in the aviary system, whereas the battery cage system resulted in the best environmental performance. As expected, prerequisites to express natural behaviour were better in alternative systems, especially if hens had access to an outdoor run. On the other hand, alternative systems seem to run a risk for a higher mortality rate due to, e.g., cannibalism or a higher disease incidence. Between farm variation in mortality rate was high, consequently differences among systems were not significant. This large variation, however, also implies potential for improvement. Physical complaints of farmers and egg quality did not differ among production systems. Overall, it can be concluded that within the boundary of this study, the aviary system with outdoor run appeared the best alternative for the battery cage system