From: Causes of mortality in laying hens in different housing systems in 2001 to 2004
Year/Housing system | 2001 | 2002 | 2003 | 2004 | 2001–2004 |
---|---|---|---|---|---|
Conventional battery cages | 66.5 | 52.3 | 26.0 | 13.5 | 38.6 |
Furnished cages | 7.5 | 12.6 | 24.2 | 24.8 | 17.6 |
Litter-based systems 2 | 22.6 | 31.2 | 43.8 | 55.0 | 38.7 |
Free range 3 | 3.4 | 3.9 | 6.0 | 6.7 | 5.1 |
Total | 100 | 100 | 100 | 100 | 100 |