Op/Ed: Dan Liebman

Twice in recent editions of Thoroughbred Daily News there has been mention of a foal being a three-quarter sibling to another. 

On Jan. 25: “Upstart's dam is a half-sister to GSW Josh's Madelyn and produced a Majestic Warrior ¾-sister to the Holy Bull winner in 2014.” 

On Jan. 19: “The (allowance) winner (Run of the River) is a ¾-sibling to Heavenly Landing, GSW, $313,115.” 
These examples are why, during my lengthy tenure at a Thoroughbred magazine, I always supported that publication's style point to never use the term three-quarter. 

There are full siblings and half-siblings. Period. 

Why? 

As these two examples illustrate, the reason is because there is no agreement on the meaning of the term. 
When most read three-quarter they assume two siblings are connected the way Upstart and the yearling produced from his dam are. 

Upstart is by Flatter; the yearling is by Majestic Warrior. Thus both are by sons of A.P. Indy out of the same mare. Looking at the pedigrees, three of the four names in the second generation are the same. 

Three of four…thus three-quarters. 

In the second example, however, Heavenly Landing is by Pulpit and Run of the River is by Tapit, a son of Pulpit. 
Looking at the second generation of these two and only two names are the same, not three as in the first example. 
Yet both are being called three-quarter siblings. 

I'm a journalist, not a geneticist, but my common sense tells me these two are not the same. 

What if you bred two mares to full brothers? 

What if full sisters were bred to the same stallion? 

Suppose half-sisters were bred to the same stallion? 

Or those half-sisters were bred to half-brothers? 

But wait, as this column was being written, the following cutline appeared in the Jan. 30 TDN: 

“This regally bred filly by Camelot was born at Coolmore Stud in Ireland overnight Jan. 28. She is out of Cherry Hinton, a half-sister to Galileo and Sea the Stars, and she is therefore a 3/4 sister to G1 Irish Oaks winer Bracelet and G2 Rockfel S. winner Wading.” 

Both Bracelet and Wading are by Montjeu, while this newborn foal is by Camelot, a son of Montjeu. 
What if you had three mares, all full sisters, and bred them to a sire, one of his sons, and one of his grandsons? 
You have three foals from the same sire line, but because you had success breeding to a sire, you decided to breed to his sons and grandsons. 

We know certain broodmare sire lines cross well with certain sire lines. That is why, though Mr. Prospector and Northern Dancer are gone, we now breed mares from certain broodmare sire lines to sires that trace to Mr. Prospector and Northern Dancer. 

With the amount of inbreeding in the Thoroughbred, countless offspring come from similar sire lines and descend from common ancestry, thus sharing some genetic makeup. 

That we can agree on. But there is no such thing as a three-quarter sibling; only full and half-brothers and sisters. Two foals are either by the same sire and dam or they aren't.