[Jacob-list] Breed Standards: Freckles, mottling

[Jacobflock at aol.com]

> Could a JSC member fill us in as to their standards on freckling?  In JSBA, 
> Under Acceptable but Less Desirable Traits, a small amount of freckling in 
> white wool is allowed.  Under Unacceptabl/Disqualifying Traits, Excessive 
> freckling in the white wool of young animals is considered unregisterable.

The Breed Standard for the Jacob Sheep Conservancy is available at 
www.jacobsheepconservancy.org.  It states in brief that mottling and 
freckling occur and is acceptable.  

The Jacob Sheep Society Breed Standard has been and may still be available at 
www.beta.co.uk/corylus/jacsoc and says mottled wool and skin are 
undersirable.

> I had also been told that Dr. Philip Sponenberg had made the comment that 
> freckling is part of the make-up of Jacob sheep and they are the only breed 
> of sheep to carry this trait.  I do not know if this statement is true or 
> not true.  
> 

Freckling in Jacobs, D. Phillip Sponenberg (1988) : ... "freckling in the 
breed is fascinating ... some genetic work suggests this is due to a dominant 
gene ... needs to be accepted as an interesting minority variant."  

The Jacob-list should not be a forum for "organization" promotion or 
comparison but a forum for sharing and learning.  The recent questions of 
freckles, ticking, skin mottling are phenotype questions that could lead to 
understanding the genotype ... not simply answered by "the breed standard for 
X organization says" ...  but by a scientific method.  There are other Jacob 
"breed standards" and organizations.   A basic genotype for the Jacob was 
given by Roberts (1926) and supported by Alderson (1975), Adalsteinson and 
Ryder (1976) ... polycerate, dominant black, recessive piebald ... and so 
many Jacob questions relate to those three terms.  

I saw a question related to "quilting" (SPOTTING locus again).  From Ryder 
and Adalsteinsson(1986): "It is a common observation in black and white 
piebald sheep that wool of one colour (usually the black) is longer and 
coarser that the other. ...It was suggested that the presence of pigment 
encourages the growth of the coarser coat, and that the colour gene will make 
the fiber array coarser since it is mainly variations in the primary and less 
in the secondary fibres that change the array.  This is pleiotropic ... 
affecting color and size of fiber ... longest wool associated with the 
thickest skin" ... etc.   Is it dominant or recessive?

Fred Horak ...  Member of JSS, JSC, JSBA




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