In the deep end of the gene pool

The covering season is upon us, so to speak.

At this time of year, thoroughbred breeders try to shape the future, arranging matings in the hope of crafting another Igugu. God's revenge on these upstarts trying to usurp his job is to give them a thumping great headache.

Anyone who has delved into the weird world of genetics will know how brain-numbingly complex it is.

There are many theories on breeding racehorses, all to do with duplicating the desirable qualities of the parents. Okay, just the one quality: running bliksemse fast.

"Family numbers", "dosages" and "cluster mares" are among the fanciful notions to investigate. There are also "nicks", proven good mating crosses.

Most of this is based on the ideas of a pea-growing monk called Gregor Mendel, who concocted the first genetics theories in the mid-19th century after keeping a close eye on how his abbey's veggie patch was shaping up.

One thoroughbred guru is Federico Tesio, a 20th-century Italian politician-cum-racing trainer, who bred several superior horses, notably Nearco, granddad of Northern Dancer, the Canadian stallion regarded as the greatest of all sires.

The Tesio method involves linebreeding, multiplying lines of superior ancestors and bringing siblings into the family mix. You must understand pedigrees to do this.

The thoroughbred strain goes back about 35 generations to three foundation horses in the early 1700s - the Darley Arabian, the Byerley Turk and the Godolphin Barb - so you're dealing with billions of ancestors, literally. I warned you this lark is challenging.

You can buy a computer program called TesioPower that does it all for you. But everyone's got one of those, so how do you make a horse that's better than the next bloke's?

I turned to The Professor, a genetics boffin handily within my family. His "idiot's guide" seemed much more sensible than those headache-inducing theory books.

The Professor reckons Mendelian theory is just half of the gene equation, namely "backcross pedigree breeding to ingress a qualitative gene". He teaches his students the wonders of another half: "quantitative genetics to accumulate good additive genes". Dead simple.

After he'd explained it to me five times, with diagrams and vivid metaphor, it all fell into place.

It seems horses, and humans, are more like cabbages than they are like mielies. Are you with me? So, following Mendelian ideas is a bit like having a hammer but no screwdriver. Breeding horses without considering "quantitative genes" is like hammering screws into wood - unlikely to produce the best results.

It's best to cultivate strictly separate genetic pools and cross-breed the very best specimens of each to create a hybrid immensely fit for purpose. Eureka! Actually, this is close to the "hybrid vigour" theory espoused by some horse breeders - and I'm sold on it.

No more of that silly "breed the best to the best and hope for the best" for me. I'm out to prove "The Professor Principle".

Now, where's that aspirin?

Turffontein, tomorrow: PA - 2, 3 x 12 x 2, 5 x 2 x 3,6 x 5,11,12 x 7, 9, 11 (R72)