[Jacob-list] Ram: Freckles/Ticking

[Jacobflock at aol.com]

In a message dated 2/22/2003 7:45:10 PM Central Standard Time, 
RnS1260 at aol.com writes:

> After sheering I found that he is quite freckled. He is also very friendly, 
> which I try to ignore and tell him to go on. The other ram is nicely marked 
> and such a gentleman but has horns very close to his head. We had to trim 
> the inside of one horn this past season. I do have several ewes with 
> freckling and would like to try to breed this out. I am considering 
> starting over with a new ram. What would your advice be for me on my 
> existing rams? I know I need to move on. Are they sellable or am I passing 
> on negative traits? 


Shearing is often "discovery" time when we see each sheep "up close".  The 
term "freckles" is commonly used to describe three observed situations; some 
genetic, some environmental. 
(1) black fiber coming from black skin as a condition from birth.  This 
condition is the result of the absence of the recessive piebald activity on 
the eumelanin (black) melanocytes (like a dye in a fiber/hair pore) that 
results in a little freckle of black fiber to appear.  The piebald pattern 
and freckles seen at birth were set up in the embryo ... neural crest cells 
along the back ... and is "sort of" fixed for life.  Melanocytes (spotting) 
come from neural crest cells ... as do cells related to the nervous system.  
Understand that at birth every primary hair follicle is associated with a 
dozen(?) secondary wool follicles. This is a "freckle".
(2) black fiber coming from spots that were NOT present at birth and continue 
to increase in number over time is the result of a ticking gene.  Ticking 
appears as increasing in number and density over time.  Ticking is dominant 
and in the extreme can get so dense as to give the appearance of a grey or 
even black fleece.  At shearing the spots may appear to have become a 
"single" spot comprised of multiple spots.  It can take time to observe and 
identify the ticking gene ... two to four years.  One downside of buying 
lambs is not knowing if the ticking gene is present.  Freckles and ticking 
can appear on the same animal.
(3) black spots on the skin that produce white fiber.  This is usually skin 
mottling but is often referred to a freckles like the spots on our skin.

There is also an environmental factor.  The UV rays of the sun can excite 
melanin and give rise to freckles as a protective reaction to UV rays.  These 
"freckles" often appear on the back of the sheep.

The down side of ticking seems to be its dominant nature.  Freckling in 
Jacobs may not be as straight forward.  Freckles may be dominant over no 
freckles. Freckles are not apparently associated with lilac Jacobs.  

There may be a market for the fiber in the handspinning group but propogation 
of the trait could be a detriment to the breed.  The freckle and ticking 
trait is noted by Jacob organizations (Britain and North America) as a 
cautionary or less desired trait.  Caution should be used so that traits are 
not bred to the extreme nor become so pervasive that the basic Jacob 
phenotype is lost.

In some cases a breeder looks for a ram lamb to use immediately in the Fall 
(say at 6-8 months of age).  Understand the Jacob matures slowly and the 
traits observed as a lamb may be disappointing as a yearling or two year old. 
 Finding a proven, unrelated ram, may take time but can benefit your flock 
and the breed over the longer term.

Fred Horak


-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.pairlist.net/pipermail/jacob-list/attachments/20030224/1d2fb58a/attachment.html