From: Causes of mortality in laying hens in different housing systems in 2001 to 2004
Bacterial diseases | Viral | diseases | Parasitic diseases | Cannibalism | |||||
---|---|---|---|---|---|---|---|---|---|
Housing system | Total no. of flocks 1 | N | % | N | % | N | % | N | % |
Cages 2 | 20 | 13 | 65.0 | 6 | 30.0 | 2 | 10.0 | 1 | 5.0 |
Litter-based systems 3 | 129 | 94 | 72.9 | 15 | 11.6 | 23 | 17.8 | 24 | 18.6 |
Free range 4 | 23 | 17 | 73.9 | 1 | 4.4 | 5 | 21.7 | 6 | 26.1 |