[Jacob-list] To tail the truth
    Jacobflock at aol.com 
    Jacobflock at aol.com
       
    Sat Jul 10 18:52:08 EDT 2010
    
    
  
Phylogenetically the Jacob's medium tail seems a logical compromise between 
 the primiitive Mouflon roots (3,000BC) and its modern ancestors 
(1600-1800AD)  Ryder 1983, Noble 1913, Elwes 1913.  Werner (1988) suggests the Jacoobs 
 relatives from Scotland and Western Britain have a similar mouflonoid 
medium  tail and horns.  Ewart in describing polycerates and mouflon influence  
focused on horn and skeletal features including the caudal vertebrae of 
Soay's  with 13 vertebrae.
 
Genetically, tail length seems to be ahighly heritable trait and the  
"average" of the parents tail length Scobie and OConnell.  Tail length  
(vertebrae, skin and fiber) is controlled by a number of genes and each element  
contributes to its "apparent" length.  The genes that control the nuimber  of 
caudal vertebrae are controlled by a set of genes that regulates cell life,  
growth, structure and death ... call them Hox genes.  In a sense, Hox genes  
send messages to make caudal vertebrae at certain places and then says ...  
that's enough of those.  Genes also control the length of the caudal  
vertebrae ... at the other end you have 7 cervical vertebrae; so does a giraffe.  
There are genes that control fat vs. thin etc.
 
A sheep can have 3 - 24 caudal vertebrae and these are rather breed  
specific: Moufloon 11, Finn Landrace 24, Cheviot 24, Orkney and Shetland 13 ....  
based on Xrays of Jacob's tails, they have 16 including the 2 at the  
pelvis.  X-ray of the vertebrae is preferred to palpating the  vertebrae ... it's 
accurate and the length of the vertebrae can be measured. 
 
As some of the old breeders know, there is a wry end to this tale.  A  
congenital defect, wry tail, has been reported several times in Jacobs; dead  
tail (a tail that does not move) is also a defect.
 
Fred Horak
St. Jude's Farm
1165 E. Lucas Rd.
Lucas, TX 75002
 
 
In a message dated 7/9/2010 8:07:15 P.M. Central Daylight Time,  
patchworkfibers at windstream.net writes:
I've seen lambs  with a kink in the tail and also don't think it had 
anything to do with being  stepped on. Both cases, the kink was inches below the 
normal docking spot.  Neither tail was below the hock. Kinks were rather 
minor. I have no idea what  caused the kinks - perhaps a jumbling as a fetal 
lamb? I haven't seen that  it's a heritable trait,so haven't paid much 
attention to it.  
Linda
Carl Fosbrink wrote:  
Some good points have been made, but  I'm surprised no one considered the 
crooked tail. I have seen several lambs  born with this and don't think it 
was caused by being stepped  on.
-----  Original Message ----- 
 
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