Intense Linebreeding: Simularities in Successful Horses

[ZiaLand]

Another thread on inbreeding got me looking at some outstanding pedigrees and I stumbled on some simularities that I found significant.

If you use the linebreeding function on this database you'll find that the following horses carry a large number of crosses back to St. Simon (not necessarily close up, but many, many occurances). As a sidenote, I also added a second number if intense linebreeding is also present to St. Simon's sire, Gallopin:

Mr. Prospector 25 (19 Gallopin)
Gone West 22
Northern Dancer 21 (27 Gallopin)
Secretariat 18 (26 Gallopin)
Storm Cat 15 (6 Gallopin)

Although the raw percentage of St. Simon in these pedigrees may not be that high (because of some of the occurances being so far back), it seems the number of occurances in the pedigrees of a particular individual may carry some importance. From what I've read of St. Simon he was a superior racehorse -- almost an anachronism in his time because he was so much better than his rivals -- and a successful sire, as well. Logic would tell me that if a modern horse carries 20 or more occurances of St. Simon in his pedigree, it seems he is more likely to inherit a good percentage of these superior genes.

So I took it one step further and looked at the linebreeding on St. Simon himself. Wow!

Herod 55
Eclipse 41
Highflyer 40
(to mention a few)

So my question is: Does having a large number of occurances tracing to an outstanding individual(s) within a pedigree increase the horse's chance of being a successful athlete and/or producer? I'd like to hear any opinions on this, or comments if you think my logic is flawed.

Laurie

[Bill from WA]

In my database, Mr Prospector has, in 12 generations, 115 lines to Touchstone, 90 to Stockwell, 74 to Pocahontas, 73 to Birdcatcher, 65 to Banter, 63 to Camel, 62 to Glencoe, and 34 to St Simon. (4374 total duplications, 3197 male, and 1177 female).

Bill

[Jeff]

I think it's about average for a TB foaled in the 70's, or early 80's to have 25 or more crosses to St. Simon in a 9 generation pedigree. Even more prevalant further back are crosses to Pocahontas, and her sons Stockwell, his full brother Rataplan, and their 1/2 brother King Tom. Stockwell is the tail male ancestor of the Phalaris so he is in the vast majority of modern TB pedigrees.

Jeff

[Johar]

In order to ascribe significance to duplications in a pedigree, you'd have to show that horses without that duplication are inferior. Just counting the St. Simon replications in top quality sires of today doesn't say much if failed TBs have just as much St. Simon blood. Also, as the previous 2 replies say, huge numbers of replications of specific ancestors are pretty much the norm in today's horses, and with several horses represented several times, which ones are important??

It's tricky business!

[Bill from WA]

Zippy Chippy in 12 generations. 157 lines to Galopin, 99 to St Simon, 97 to Hermit, 92 to Stockwell, 48 to Pocahontas. 4127 duplications, 3114 male, 1013 female. Hard to read anything into this type of information except that the Thoroughbred is a very inbred creature.

Bill

[ZiaLand]

Thanks everyone, for your feedback. I can see your points on why the duplicated occurances of one particular individual in a pedigree probably isn't indicative of a horse's success/failure, but I still believe linebreeding influences are a significant factor in breeding success.

Bill, what software are you using to go back 12 generations in your research? Tesio?

Laurie

[Bill from WA]

Hi Laurie

Yes I use Tesio Power. Couldn't get along without it.

Bill

[louis finochio]

Line-breeding of superior individuals, stallions or mares is done to make those dominate traits carried down to the decending generations.

The breeder must weed his garden of inferior individuals, as this line-breeding magnifies the bad with the good.

My most successsful unions have been line-bred individuals on the sire side and line-bred on the dams side, but the two families are not related, thus keeping the hybrid vigor, and soundness alive and well.

Any time you have a duplication of superior producers top and bottom in an individual, your chances producing the big horse is magnified.