Íslenskar landbúnaðarrannsóknir - 01.09.1974, Side 7

SHEEP PARASITES IN ICELAND 5
given anthelmintica. They were divided into
two groups:
Group IV Group V
3 female lambs 3 female lambs
No anthelmintica Thiabendazole 3g
September 27, 1972.
From March to June 1973 faecal samples
from 11 yearlings (born May 1972), 6 two
year old and 10 adult sheep (older than 2
years) were studied. All had been given
thiabendazole 8th of December 1972. They
were divided into four groups:
Group VI
1 male yearling
1 two year old ram
1 adult ram
No anthelmintica
Group VIII
4 female yearlings
2 two year old ewes
2 adult ewes
Thiabendazole 3g
April 3, 1973
Group VII
2 fernale yearlings
2 two year old ewes
4 adult ewes
No anthelmintica
Group IX
4 female yearlings
1 two year old ewe
3 adult ewes
Thiabendazole 3g
May 3, 1973.
From May to June 1973 twelve young
lambs were studied (Group X). From 6 of
the lambs, born May 5 —12, faecal samples
were collected two or more times. From the
other 6, born May 5—23, faecal samples
were collected once (June 14).
The rest of the flock, which was not in-
cluded in the study was given thiabendazole
in the spring 1971, in December 1971, in
April 1972 and in December 1972.
Faecal samples were taken once a week in
the morning, except during the summer when
the sheep were on the mountain pastures.
The number of Eimeria ovocysts and
helminthic eggs pr g faeces were counted by
a slightly modified McMaster technique
(Helle 1971). The number of Eimeria
ovocysts was counted in one sixth of each of
four McMaster chambers. The number of
helminthic eggs was counted in four cham-
bers.
The nematode larvae were collected from
3g of faeces by a sligthly modified Baermann
technique (Henriksen 1965). The number
of larvae pr g faeces was usually estimated,
but sometimes counted exactly as a control.
The faecal consistency was classified into
four categories (Helle 1971) : l=normal
pelleted, 2=soft pelleted, 3=paste, and
4=liquid or semiliquid.
EÍMERIA SPP
There were several different species of
Eimeria in the sheep faeces, but no attempt
was made to distinguish between species in
this study.
The number of ovocysts in the faeces of
lambs during the first weeks after birth was
followed in the spring of 1973 (Group X).
The results are presented in Fig. 1.
None of the lambs showed any evident
sign of coccidiosis.
In order to get a clearer picture of the
variation of the number of Eimeria ovo-
cysts it would have been necessary to take
samples more frequently than once a week.
Therefore it is quite possible that the highest
value of ovocysts pr g faeces was not ob-
tained in any of the lambs.
The youngest lamb in which ovocysts were
found in faeces was 22 days old, and by the
age of 30 days, ovocysts had been found in
all the lambs. This means that the lambs
must have already become infected the first
days after birth. The number of ovocysts
most likely reached a maximum of several
hundred thousands or more pr g faeces a few
days after their first appearance, and then