Ascarid infections in laying hens kept in different housing systems.

The present study was undertaken to investigate the prevalence of ascarid infections in Swedish commercial laying hens in 2004 and 2008 following a recent nationwide change to alternative housing systems but before anthelmintics became available. Also, the influence on prevalence of farm and flock characteristics and management was studied in 2004. The results showed that the overall prevalence was significantly higher in 2008 (38%; n = 64/169) compared with 2004 (24%; n = 44/186) (P = 0.

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

Background: The husbandry systems for laying hens were changed in Sweden during the years 2001 - 2004, and an increase in the number of submissions for necropsy from laying hen farms was noted. Hence, this study was initiated to compare causes of mortality in different housing systems for commercial laying hens during this change.

Methods: Based on results from routine necropsies of 914 laying hens performed at the National Veterinary Institute (SVA) in Uppsala, Sweden between 2001 and 2004, a retrospective study on the occurrence of diseases and cannibalism, i.