The mysteries of the color and
pattern genetics
makes raising Icelandic
sheep extremely interesting. The white ewe at left
developed a mysterious blue/grey spot on her
back after shearing in the fall. I suspected that she
carries the grey gene as her recessive, since her
sire is a black/grey ram.  Her base pattern is
white, which covers up her secondary pattern.
Usually white sheep are pure white, or exhibit
some tan phaeomelanin markings (as seen in her
face), but occasionally mysterious markings do
appear.

Sure enough, Gwendolyn's first lambing produced
a set of twin ewes: one was white and one was
grey! She had been bred to a black badgerface ram,
so the grey lamb was a result of the recessive grey
gene that I suspected she carried. This was the
first time I had seen evidence of the underlying
pattern showing up on the sheared coat of a white
sheep and it was fun to know that my guess was
correct. Gwendolyn has gone on to lamb many
more times for us and she always produces either
white or grey lambs.