Causes of mortality in laying hens in different housing systems in 2001 to 2004

Table 4 List of miscellaneous diagnoses in 173 necropsied laying hens, not included in main diagnostic categories and the statistical analysis.

		Housing of the birds (no. of flocks)
Diagnosis	No. of hens	Cages ¹	Litter-based systems ²	Free range ³
Visceral gout	29	1	10	1
Unknown cause of death	23	6	17	0
Dehydration and cachexia	17	0	6	0
Trauma	16	2	12	2
Hepatic lipidosis and liver rupture	11	3	2	0
Circulatory disturbances⁴	16	0	3	0
Anaemia and haemorrhages, suspected intoxication	11	0	0	1
Osteoporosis	10	4	0	0
Egg bound	7	3	4	0
Hepatitis	5	0	4	1
Obstipation (straw)	5	0	1	2
Miscellaneous neoplasms⁵	4	1	3	0
Other causes of death⁶	19	2	17	0

¹Includes conventional battery cages and enriched cages.
²Includes single-tiered floor systems and multi-tiered aviary systems.
³Flocks housed in litter-based systems indoors, with access to outdoor pens and pasture, including organic flocks.
⁴Botulism was later diagnosed from hens in the same flocks.
⁵Neoplasms other than lymphoid leukosis.
⁶Including egg yolk peritonitis (n = 4), gastritis (n = 2), ovarian cyst (n = 2), air sacculitis (n = 2), enteritis (n = 2), chronic salpingitis (n = 1), endocarditis (n = 1), intestinal volvulus (n = 1), myositis (n = 1) ruptured ovary and abdominal hemorrhage (n = 2). hepatitis (n = 1).

ISSN: 1751-0147