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SHETLAND SHEEP
PATTERNS AND MARKINGS
© Kathy Baker Oct 10 2005
Resources:
Colour Census Illustrated, Sue Russo, 1995
(This binder is a compilation of representative photographs sent in
by 109 members of the Shetland Sheep Society, formerly called SSBG,
to Sue Russo).
Colour Inheritance in Icelandic Sheep,
Dr. Stephan Adalsteinsson, Journal of Agricultural Research,
Iceland, 1970
Foula Sheep,
Sheila Gear, Editor Sue Russo, 1991
Markings in Shetland Sheep,
Poster, Sue Russo, SSBG, 1997
Shetland’s Native and Domestic Animals,
Dr. Stanley Bowie, 2005
1000 Years of Sheep in Shetland,
Dr. Stephan Adalsteinsson, International Shetland
Sheep 2000 Conference Proceedings, 2000
The North American Shetland Sheepbreeders
Association and the Shetland Sheep Society of the UK use a common
list of 30 Patterns and Markings In Shetland Sheep. This list can
present a challenge to new and experienced breeders alike, who are
trying to register their sheep as accurately as possible. Below,
the 30 recognised
Patterns and Markings are divided into groups rather than listed
alphabetically to make the list easier to understand and search. I
hope this will provide a quick online reference for breeders.
Input is welcome and encouraged. Please
e-mail me (Kathy Baker) at the address below if you have any
suggestions, information or clear pictures you would like to
contribute. I am also interested in pictures of any sheep which are
not easily described by the Patterns or Markings on the list.
In looking at the statistics for the frequency
of usage of the 30 terms in the NASSA Flock Books, it is apparent
that some terms are not used very frequently. The Colour
Census taken in the UK in 1995 provides a similar pattern of
frequency of use for the 30 terms. There are a number of possible
reasons for this:
1. The Pattern or Marking may be rare.
2. The Pattern or Marking term is redundant
i.e. there are other terms on the list which better describe or
appear to describe the same feature.
3. The definition is not clear and so it is
simply not used.
On a trip to the Shetland Islands in 2003, I
learned that some of the terms were used more as descriptive words
or adjectives and were not necessarily meant to label a persistent
marking and also that terms varied somewhat among different areas of
the Shetland Islands.
Sheila Gear in her book, "Some Notes on Foula
Sheep", makes this last point quite clear:
“Shetland consists of a lot
of different Islands and the dialect varies a lot between them. May
of the words used for colours and patterns are not longer in use;
which makes things even more confusing! Now you will only hear
“sneedled” in Foula. On the Shetland Westside, it is called
“sholmit”, a word that Foula folk only use for cows with white
faces.”
However, don't despair! While some terms may
vary and may cause a bit of confusion when reading the definitions
or doing further research, most are used very consistently and have
been for many years. In many cases, the terms can be correlated to
similar Icelandic or Norse words that have been in use for as long
as 1000 years, according to Adalsteinsson. Today, we can also take
into account our current knowledge of genetic theory to help
understand and use the terms.
Also, as with the colour chart, some sheep
don’t fit neatly into any one category. There are a number of
points to consider:
1. The marking or pattern may be
incomplete or weak. For example, the sheep
may have only a thin necklace of white around the neck which may
hardly be visible in full fleece.
2. The marking or pattern may be
completely or partly masked by dominant genes
at Agouti. For example, a Grey Flecket lamb may show the
characteristic Flecket marking of patchy black/grey with white in
the first year, but after that first fleece is shorn, the fleece
appears to be almost all “white” or very light grey. There may only be
some small patches of black showing in the hair on the legs or face
as a tell tale sign of the Flecket marking.
3. The marking or pattern may be
blurred by the simultaneous expression of co-dominant genes.
For example, Adalsteinsson, in "Colour Inheritance In Icelandic
Sheep", shows a picture of lamb that is AbAt or Katmoget/Gulmoget
together, resulting in neither pattern showing clearly.
4. An Ag sheep may have some measure of
inconsistent pigment in the skin/fleece which may be mistakenly
identified as spotting. This is seen especially in lambs. (See pictures of
Inconsistent Pigmentation)
5. Spotting (SsSs) is defined
by Adalsteinsson as white patches on a coloured background. In
a Flecket sheep with extensive white spotting /markings, it may
appear to your eye that you are looking at black spots on a white
background but it is actually the opposite. All markings referring
to spotting genetics a the S Locus are white.
6. Tan or pheomelanin
is often visible in white Awt – white or Ag sheep.
The fleece or hair areas such as face or legs, may look like light
brown/tan “spots” or patches. This is not the Spotting which is controlled by the Spotting
Locus S.
7. Pheomelanin may also give the
inexperienced eye the impression that a black based Ag or Grey sheep
has brown on it as well. See Pictures of Heavy Pheomelanin
Expression to help understand what this looks like.
Note that Katmoget and Gulmoget are referred to
as Patterns. These Patterns are expressed as a result of specific
genes at the Agouti locus, labeled Ab for Katmoget and At for
Gulmoget. The phenotype of the sheep (or how the sheep looks) is a
predictable and distinctive coloration in the face and body. White
Markings, are controlled at the Spotting Locus S.
Adalsteinsson in his article: "1000 Years of
Sheep in Shetland", says:
“Two
Colour patterns are found in Table 2 (the common list of 30 Patterns
and Markings)…These patterns are Gulmoget and Katmoget…these
phenomenon are not markings, but patterns….”
Note that the remaining list of 28 Markings are not all white
markings controlled by the S Locus but describe other
characteristics consistently seen with Shetland sheep. White
markings are denoted by their current genetic code at the S locus.
SsSs. (It is likely that the genetic code is more involved
than the simple presence of 2 recessive copies at S to provide
the variety of white markings seen below.)
To learn more about Colour Genetic Theory see
COLOUR GENETICS
The 30 Patterns and Markings are divided
below into:
2 Patterns
13 Head Markings
3 Neck Markings
1 Leg Marking
11 Body Markings
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