[Jacob-list] To tail the truth

[Linda]

Please excuse my erroneous statement regarding heritability of tail 
length. I was referring to the slight variation seen in purebred Jacobs, 
rather than the extreme variation that indicates cross breeding.

Linda

Jacobflock at aol.com wrote:

> 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.*

>>

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>

>     -- 

>     Patchwork Farm Jacob Sheep <http://www.patchworkfibers.com/>

>

>

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Patchwork Farm Jacob Sheep <http://www.patchworkfibers.com>
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