The themes of my first two articles in this series have been that, firstly, luck is the central component to breeding success and, secondly, that inbreeding, for all the theories that abound and the thousands of column inches which have been written extolling its virtues, is very much a two-edged sword.
I’m not arguing that inbreeding is doomed to fail – or that it has no place in the thoroughbred breeder’s arsenal. All I’m saying is that it’s a technique that needs to be used with caution – especially as there is some extraordinarily dodgy science referenced in the most reputable publications, “science” which seems to suggest that sex-balancing stallions or mares in a pedigree is the recipe for success.
For the life of me, I just can’t see how this works. To begin with, when you’re breeding anything – humans, horses or hamsters – you do get some quite unexpected results. I’m not trying to be offensive, but just think of your own relatives. Sure, they are highly unlikely to be the result of inbreeding but there will be some surprises out there. If you are inbreeding, and I’m not writing about humans here, there’s still an awful lot of variability involved.
One reason why inbreeding enthusiasts sometimes are disappointed by the results of their efforts is that they have made one fundamentally incorrect assumption – that when a name appears more than once on a pedigree printout it means the same thing – in terms of genetic inheritance – on both occasions. As an example, let’s look at Zabeel and a couple of his sire sons, Savabeel and Zed. Even a cursory inspection of these two animals will show that there is a significant difference in their physical make up. Now let’s fast forward 15 years and assume we have a grand-daughter of Zed and we’re thinking of sending her to a grandson of Savabeel because we’re rather keen on Zabeel blood. Are we really increasing our chances of a significant number of those magic Zabeel genes ending up in our foal?
I think not.
