Íslenskar landbúnaðarrannsóknir - 01.09.1974, Síða 21

SHEEP PARASITES IN ICELAND 19
In late September when the sheep come
back to the farms, the faecal consistency is
about 2. 5—3 but then it falls and in Nov-
ember it is down to 1—1. 5. Thereafter it
rises gradually through the winter and is
back to 3 in June when the sheep go to the
mountain pasmres. No significant age nor sex
differences could be detected. This variation
is shown in Fig. 16.
The effect of thiabendazole on the faecal
consistency varies depending on the time of
year (Fig. 15). Drenching in September or
December does not seem to have any effect,
however drenchings in April or May seem in
some cases to harden the faeces but this does
not last longer than 2—3 weeks.
There are several factors which can influ-
ence faecal consistency of sheep, i.e. changes
in diet, stress (. ex. lambing), several dis-
eases and parasitic infestation.
The variation in faecal consistency in this
study can possibly be related to changes in
ADDENDUM
The author realizes that the results obtained
can only be considered valid for this parti-
cular farm during the course of the study.
ACKN OWIEDGEMENTS
I am indebted to the farmer Einar Ólafsson
and his family for allowing me to carry out
this smdy on their farm Gesthús and for
much appreciated help and cooperation.
Furthermore I wish to thank the following
for their technical assistance: Torfhildur Sam-
diet such as differing water content of the
fodder. Stress of lambing can be excluded
here as a major cause of variation in faecal
consistency since both sexes showed the same
pattern.
If we consider parasites to be a major
cause of variation in faecal consistency, we
might rale out those which do not vary
clearly in numbers in relation to the time of
year and those which vary considerably in
relation to the age of the sheep. This would
exclude in this case the following species:
Eimeria spp. (except possibly in newborn
lambs) Moniezia expansa, Nematoiirus spp.,
Muetterius capillaris and Dictyocaulus filaria.
As far as this study is concerned, this
leaves only the group „other strongyles" as
a possible cause.
It is most likely however that variation in
faecal consistency cannot be related to a
single factor only.
However, it is possible that the various
hypotheses presented are applicable for many
other farms in Iceland.
úelsdóttir, Pétur Sigurðsson, Roger Lutley,
and Vilhelmína Gunnarsdóttir.
Finally I want to thank Guðmundur Pét-
ursson, Páll A. Pálsson and Sigurður Sigurð-
arson for their helpful comments and special
thanks to Sigurður Sigurðarson for helping
me to start this investigation.