Table 5 Risk analysis regarding main disease categories between laying hen flocks in cages1 and litter-based systems2.
From: Causes of mortality in laying hens in different housing systems in 2001 to 2004
Disease category | Observed no. of flocks from litter-based systems | Expected no. of flocks if same risk as in cages | Excess no. of flocks in litter-based systems compared to cages |
|---|---|---|---|
Bacterial diseases | 94 | 9 | 85*** |
Viral diseases | 15 | 4 | 11*** |
Parasitic diseases | 23 | 1 | 22*** |
Cannibalism | 24 | 1 | 23*** |
Total | 129 | 14 | 115*** |