Íslenskar landbúnaðarrannsóknir - 01.09.1974, Page 10

8 ÍSLENSKAR LANDBÚNAÐARRANNSÓKNIR
Fig. 4. Eggs of „other strongyles" in faeces of
lambs (age 4—7 months) (Group IV).
that the lambs were infected soon after birth.
Since 3—6 weeks must pass from the
time of infection to the first appearance of
eggs in faeces it seems probable that when
the lambs are sent to the mountain pasmres
(about 20th of June) the infection in lambs
only partly manifests itself as eggs in faeces.
Therefore it is likely that the number of
eggs pr g faeces will increase during the next
1—2 months, unless resistance develops.
The number of eggs in the faeces of older
lambs and sheep was also recorded through
the year, except for the summer period. Some
results are shown in Fig. 4 and 5.
During the middle of the summer, the
sheep are spread over vast areas on the moun-
tain pasmres, and therefore it is less likely
that an infection will be acquired as readily
as when the sheep are kept in the smaller
grazing areas near the farm. Assuming that
the rate of infection is lower during the
Fig. 5. Eggs of „other strongyles" in faeces of lambs (age 6 months —-114 year) and adult sheep
(older than 2 years) (Group I).