Íslenskar landbúnaðarrannsóknir - 01.03.1970, Page 25

COLOUR INHERITANCE IN ICELANDIC SHEEP 23
TABLE 1
Progeny of ram No. 01063, grey badgerface, used in 1957/38
Colour of progeny
Colour of ewes Black
White Grey badgerface Total
White (heteroz.) 4 2 2 8
Black 0 3 4 7
TABLE 2
Progeny of ram No. 01073, black bagderface-mouflon, used in 1958/59
Colour of progeny
Colour of ewes White Grey badgerface Black badgerface Grey mouflon Black mouflon Total
White (heteroz.) 6 0 3 0 3 12
Grey 0 1 1 1 1 4
Black 0 0 2 0 4 6
Brown 0 0 1 0 0 1
probability of this occurring if the ram
was heterozygous for brown colour is
(0.75)10 or 0.0317. The mating to the
brown ewe, where the probability of brown
was 0.5 if the ram liad been heterozygous,
brings the probability of all black progeny
from a heterozygous sire down to 0.0158.
From this test it may be assumed with
high degree of confidence that the ram
was not heterozygous for brown colour.
The brown ewe in table 2 showed no
white markings. She was sired by ram No.
01519, a brown ram witli white markings.
Only one other ewe mated to ram No.
01073 could be expected to be heterozyg-
ous for white markings. The brown ewe
gave a black badgerface lamb with exces-
sive white markings (colour 0330) while
none of the other lambs showed white
markings.
Ram No. 01073 was thus found to carry
the genes for badgerface ancl mouflon patt-
erns as alleles. He was most likely homo-
zygous for the gene for black pigment ancl
heterozygous for a recessive gene for white
markings.
When the results given in tables 1 and
2 had been obtained it became obvious
that the genes for grey, badgerface and
mouflon could be treated as equal in many
ways. Tliis was of particular interest with
respect to their relationship to the gene
for white.
Early investigations of flock records and