Chicken welfare is influenced more by housing conditions than by stocking density

Acknowledgements We benefited from discussions with J. M. Brown, O. L. Anderson, M. Ross and R. Boehler. We acknowledge F. H. Streitz for the formulation of equations (2) and (3). We are grateful for the technical efforts of S. Caldwell, E. Ojala, L. Raper, K. Stickle. Work was performed by the University of California under the auspices of the US DOE by the Lawrence Livermore National Laboratory.