1. A cross-sectional prevalence study of gastrointestinal helminths in Dani
sh poultry production systems was conducted on 268 adult chickens selected
at random from 16 farms in Denmark from October 1994 to October 1995.
2. The trachea and the gastrointestinal tract of each bird was examined for
the presence of helminths.
3. In the free-range/organic systems the following helminths were found: As
caridia galli (63.8%), Heterakis gallinarum (72.5%), Capillaria obsignata (
53.6%), Capillaria anatis (31.9%) and Capillaria caudinflata (1.5%). In the
deep-litter systems: A. galli (41.9%), N. gallinarum (19.4%) and C. obsign
ata (51.6%). In the battery cages: A. galli (5%) and Raillietina cesticillu
s or Choanotaenia infundibulum (3.3%). Exact identification of the cestodes
was not possible because of missing scolexices. In the broiler/parent syst
em: C. obsignata (1.6%), and finally for the backyard system: A. galli (37.
5%) H. gallinarum (68.8%), C. obsignata (50.0%), C. anatis (56.3%) and C. c
audinflata (6.3%).
4. The results confirm the higher risk of helminth infections in free-range
and backyard systems but prevalence may also be high in deep litter system
s.