Íslenskar landbúnaðarrannsóknir - 01.03.1970, Page 6

4 ÍSLENZKAR LANDBÚNAÐARRANNSÓKNIR
mentation proceeded it became clear that
the inheritance of the grey colour was only
a part of a greater complex. It was there-
fore decided to make a broader investiga-
tion of the colour inheritance in the Ice-
landic sheep in order to obtain as com-
plete picture of the whole complex of
colours as possible.
Facilities for the initial experimentation
were made available at Hestur, the experi-
mental farm of the Department of Agri-
culture of the University Research Insti-
tute. In 1959 the Institute made available
funds to establish an experimental sheep
flock for colour inheritance studies at the
farrn Skeiðháholt in Árnessýsla. Later on
several experiments were carried out on
private farms, and data from private flock
books were also obtained and added to the
experimental data.
CHAPTER I
The Icelandic sheep and sheep husbandry practices
A. THE SHEEP BREED
The only breed of sheep in Iceland is the
native, Icelandic breed, brought to the
country by the Norwegian settlers at the
time of settlement of the country in the
period 874—930 (Sigurdsson, 1937).
This breed belongs o the North Euro-
pean short-tailed group of sheep, ancf its
nearest relatives are belived to be the Old
Norwegian sheep (Spaelsau), the Swedish
Landrace, the Finnish Landrace, and the
Shetland and Orkney sheep (Pálsson,
1944).
There liave been some imports of sheep
to Iceland during later centuries, mainly
in the I8th, I9th ancl 20th centuries. In
most of these cases the imported sheep
brought with them diseases which were
disastrous to the native sheep population.
During eradication of the diseases by
slaughtering of infected stock, the import-
ed sheep and their crosses liave almost al-
ways been slaughtered as well, so the im-
ports are befieved to have had very little
effect on the breed as a whole (Sigurds-
son, 1937).
The wool of the Icelandic sheep is pre-
dominantly a mixture of long, coarse, out-
ercoat fibres and short, fine undercoat
fibres. Some kemp also occurs (Adalsteins-
son, 1956).
B. SHEEP HUSBANDRY PRACTICES
1. Size of slieep flocks
The slieep flocks in Iceland vary in
numbers from 250—500 winterfed ewes on
farms where the main income of the
farmer comes from the sheep production.
Several farmers whose main source of in-
come is from dairy cattle also keep some
sheep, and the flocks on the latter farms
are usually mucli smaller.
2. Grazing and housing of sheep
The sheep are kept on common moun-
tain pastures from late June or early July
until the latter half of September. At the
end of the mountain grazing period thev
are taken down to the lowlands, and the
lambs not intended for breeding are
slaughtered in late September ancl October.
All winterl'ed sheep are lioused during
the winter, but the onset of the housing
time varies considerably from one district
to another. Entire rams, however, must,