[Jacob-list] Breeding Question

[Linda]

On this list, Fred Horak  stated:

> OCD is a malformation of the condyl (unequal condyls) at the

> atlanto/occipital joint; the first bone structure joiining the 

> vertebrae and skull. It is a

> congenital defect that may exhibit no abnormal nec k carraige in 

> its mildest

> form to ataxia in more svere forms.  Any apparent carraige 

> mispresenment or

> ataxia is related to the severity of the dysplasia.  OCD and LSD 

> exhibit similar

> patterns of behavior; a necropsy is the only way to confirm the 

> problem; both

> seem to be recessive.  OCD and LSD are found in both two horn and 

> polycerate

> Jacobs. Evidence suggests it is recessive.

> 

> There is no evidence to support a conhclusion that OCD and SUED are 

> related.

> 

> hope this helps clarify the issues.;l

> 

> Fred Horak





>Actually they are more than likely talking about a form of OCD (Osteocondritis Dissicans), which affects the joint at the base of the scull that attaches the head to the neck. Basically the little pieces that stick out from the bottom of the head look tweaked... a condition also know as OCD (Occipital Condyle Dysplasia), which causes the lambs to be paralyzed, wobblers (ataxia), fall over, or just be unthrifty in severe enough cases. It is a disorder that can be found in any breed of livestock, and humans, but for some reason is more prevalent in the Jacob Breed of sheep. Some people say that breeding a two horned to a four horned will help reduce the likelihood of having any problems with OCD, and that OCD is only found in 4h stock. I do all my own butchering, and found a perfectly healthy lamb with two horns, out of a two horned dam, and four horned sire, with a sever case of OCD. He did not display any ataxia, nor was he unthrifty. The dam and sire where both butchered... for other reasons, neither of which displayed any degree of abnormality of the occipital condyles. One half brother (sire line) was butchered, and was found to have even more severe condyllar dysplasia, another half brother out of the same sire, and a very similar dam line, was completely normal. Once I receive the radiographs, I will make them accessible to everyone, as they are very interesting, and noticeable cases. Good luck with your new sheep, and I wouldn't worry too much about breeding 2H to 4H, just pick the absolute best, and healthy stock you can, and go from there. It's really all you can do, but remember don't toss out the opportunity to use a good two horn, as they are usually cheaper, and give you just as nice, REGISTERABLE offspring! We have had some perfect sets of four horns sired by two horned rams, over four horned ewes. Just look at both the sire and dam's 4h parentage if you have the chance. The Jacob Genepool is just too shallow to toss out good genetics over a single trait that isn't even considered a fault by registry.<







Lynette Frick
IDEAL FARM 
 Jacob Sheep
www.idealjacobsheep.com



  
http://www.patchworkfibers.com 
Registered Jacob Sheep, Handspun Yarn  
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