The scheme was repeated during 2 vegetation
periods with flock X1 (starting at around 8 mo
of lay) from April to the beginning of August of
the first vegetation period and flock X2 (whole
laying period) from August of the first to August
of the second vegetation period.
The effect of replacing woodchips on the area
in front of the henhouse on turf quality and para-site infection was tested on farm Y. Four groups
of layers, comprising 2 replicates (YA, YB and
YC, YD) were investigated during an experi-mental period of approximately 12 mo and re-peated with new birds in the following year:
The first 10 m of the paddocks of groups YC
and YD were covered with approximately 25 cm
of wood chips (mainly beech, approximately 3
cm long; ~200 m
2
/1,000 hens); the paddocks of
groups YA and YB remained unaltered (Figure
1). The total surfaces of paddocks A to D were
identical (2,500 m
2
for 500 hens).
Data were recorded during 2 laying periods
with flock Y1 (ending in June of the first vegeta-tion period) and flock Y2 (ending in June of the
second vegetation period). Flock Y2 was treated with flubendazole [12] at a dosage of 10 mg/
kg of BW as a feed additive over 7 d after the
first vegetation period. This treatment is in ac-cordance with organic standards in Switzerland
if prescribed by a veterinarian.