[Jacob-list] Generations, Genetic Diversity, and Culling Pressures

[Linda]

Nicely said.



Lynette Frick wrote:

>

> Hi Zach,

>

> The importance of generations is in the theory behind them. The more 

> generations you have registered the higher the chances that that 

> animal is truly a pure Jacob. Its somewhat like a guarantee from the 

> registry that that animal is pure, at least to the number of 

> generations that they have record of. The higher the letter, the more 

> chances that that animal will produce true to type. Even if you aren't 

> seeing pictures of grandparents, ggrandparents, etc. you know that 

> those animals where inspected, deemed pure, and met the minimum 

> requirements for registration. That's the importance behind the letters.

>

> I wouldn't suggest buying unregistered stock, or FF stock, unless you 

> absolutely know the person that you are purchasing from, the history 

> of their flock, and are confident in your own abilities to pick out 

> crossbreds, even a generation or two into it. Also, you must realize 

> that just because a sheep is FF stock doesn't mean that you are being 

> guaranteed genetic diversity, it just means that somebody didn't keep 

> up with their registrations. For example, I purchased all my first 

> sheep from Mr. Anderson also. If I hadn't registered or kept records, 

> and just used the Hillside genetics that I started with, then what I 

> would have where a bunch of unregistered pure bred Jacob sheep with 

> extremely concentrated Hillside genetics, and no way to tell you who 

> they are.

>

> I'm going to agree with the others on the list in saying that knowing 

> lines/ flocks is much more important in my book than the letter of 

> registration. And the best way to keep your sheep genetics healthy is 

> to do serious homework into the background of any animal you are 

> interested in adding to your breeding program, registered or not. 

> Genetic diversity comes in the form of finding a sheep with genetics 

> most distant from your own sheep. Take note, that if all the names 5 

> generations back are the same, you're still looking at genetics that 

> are very close to what you already have. This is where it comes in 

> handy to have a program like Tenset technologies "Breeders Assistant", 

> so that you can see what the Inbreeding coefficient would be if you 

> where to hypothetically mate two particular animals.

>

> As for your other question, about the progressing of generations in 

> relation to the commercialization of the breed, I would have to say 

> that the two items are completely unrelated. Will it lead to a more 

> uniform, or "standardized" jacob, probably not, as there is 

> enough wiggle room in the breed standard to allow each shepherd to 

> select what he likes, and each shepherd is different. Also keep in 

> mind that not  all sheep that are unregistered are kept running wild, 

> so one can't say that there is any guarantee that you are getting more 

> "primitive" sheep that have been under less artificial selection than 

> sheep that are registered.

>  

> What you need to look at are the selection pressures of the shepherd 

> in particular you would be potentially purchasing sheep from, and how 

> much infasis they put on them. Is the shepherd strictly breeding for 

> beautiful sheep with great markings, and lovely soft fleeces, and if 

> so what do they do with their weaker sheep? That hard to come by ewe 

> who meets their demanding requirements for a particular look, but 

> maybe she gets scours every once in a while, or they have to pull her 

> lambs every year. Is she still in their breeding program? (Worse yet, 

> is the the mother of herdsires?) If you want beautiful sheep at all 

> costs, what you will eventually end up with are miniature spotted 

> Suffolks. They look great, die for no reason, and tend to have a hard 

> time counting(lambs). This is where production records come in handy, 

> and they along with pictures should be your guide to your purchases.

> Look for sheep that are produced in a system similar to your own, and 

> that have production records behind them. For example I have a small 

> property, so my sheep are kept in a dry lot for part of the time, and 

> MIG grazed the other part. What this means is that my ewes have to be 

> able to hold up to parasite pressures better than a sheep that is MIG 

> grazed on 100 acres, or a range ewe that doesn't see a particular 

> property again until next year. If I have a sheep that is weak to 

> parasites they generally show it fast, look rough and get diarrhea. I 

> could do like my friends with their show sheep and treat them 500 

> times, or I can keep my records, treat it once or twice, and if the 

> problem persists, put her in the freezer. Beautifully conformed, near 

> perfect sheep $250 or not, she doesn't belong if she is not thrifty.

>  

>  Health should be every shepherds overall goal, and selecting for such 

> over and beyond all our other selection goals is our only way to keep 

> the Jacob Breed of sheep from falling prey to the same fates as other 

> farm flock breeds. (I hesitate to call them commercial, as true 

> commercial range sheep get less care, and are more hardy than even 

> some of our Jacobs could ever hope for) Its ok, and of coarse even 

> extremely necessary to select for visible traits, but we must keep in 

> mind that the pressures put on the Jacob Breed in its development 

> meant that the weakest, least adapted sheep died, and that if we want 

> hardy true to type Jacobs we have to put feelings behind us and make 

> sure to include hardyness in our culling and selection decisions.

>  

> Just my two sense, hope it helps!

>  

> Lynette Frick

> IDEAL FARM

> Jacob Sheep

> www.idealjacobsheep.com <http://www.idealjacobsheep.com/>  

>

>

>  

>

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