Íslenskar landbúnaðarrannsóknir - 01.03.1970, Blaðsíða 24

22 ÍSLENZKAR LANDBTJNAÐARRANNSÓKNIR
showed two patterns simultaneously, it
was decided to keep it for breecling ex-
periments.
The dam, No. 01104, had previously pro-
duced two black badgerface lambs when
mated to a white sire which was known
to sxre black lambs, and the sire, No.
01035, had never given any badgerface pro-
geny except where that pattern was present
in the dams.
The grey badgerface ram lamb, which
was given the flock book number 01063,
was therefore most likely heterozygous for
the genes for botli grey and badgerface.
When mated to black ewes he was there-
fore expected to give progeny which segre-
gated accoiding to the ratio:
1 grey baclgerface,
1 grey,
1 black badgerface,
1 black,
assunxing the genes for grey and badger-
face to be at different loci without link-
age.
The result of mating this ram to black
ewes and white ewes which had given
black lambs before was that only two co-
lours appeared in the nonwhite progeny,
grey and black badgerface, while grey
badgerface and black colour were absent.
The results obtained are shown in table 1.
The results indicated strongly that the
genes for grey and badgerface were alleles.
2. Badgerface and mouflon
In 1958 another ram lamb born in the
experimental flock at Hestur was found to
show a combination of two patterns, this
time the badgerface and the mouflon patt-
erns (colour 1200). The sire of this lamb
was ram No. 01064, which was a black
badgerface with white head spot, white
collar and white socks (colour 0362). Ram
No. 01064 was known to be heterozygous
for the badgerface colour, ancl none of his
progeny except this one showed the mou-
flon pattern. The dam of the lamb was a
black mouflon ewe, (colour 0400), No.
01164, which had earlier given nonwhite
lambs without the mouflon pattern, but
never before a lamb showing the badger-
face pattern.
This lamb is as far as is known to the
author, the first lamb of this colour com-
bination ever recordecl. He was kept for
breeding experiments; his flock book
number was. No. 01073. From the breed-
ing history of his parents lie was likely to
be heterozygous for the genes for both
patterns.
Ram No. 01073 was mated to white,
grey, black and brown ewes tlie next wint-
er, and the results are given in table 2.
The segregation in table 2 strongly in-
dicated that the genes for the badgerface
and mouflon patterns were allelic, and
therefore both allelic to grey.
The sire of ram No. 01064 was ram No.
01515, which was brown with white blaze,
white collar and stockings (colour 0962).
As it was at tliat time anticipated that
the occurrence of both brown colour and
white markings was due to the homozygous
condition of recessive genes, ram No. 01073
was expected to be a carrier of the gene
for white markings and possibly also a
carrier of the gene for brown colour.
Of the white ewes giving nonwhite
lambs, 3 had earlier given brown lambs,
while 7 of the progeny out of the grev
and black ewes were out of dams which
had previously given brown or grey-brown
lambs. Assuming the white ewes to be
heterozygous for the gene for brown, this
amounts to testing the ram on 10 progeny
out of ewes heterozygous for brown colour.
None of the progeny were brown, and the