Markus Jooste isn't scared to go big. Follow the business news and you'll know this guy has a voracious appetite for growing his commercial empire. Just recently his Steinhoff group gobbled up Poundland discount store chain in the UK and, for dessert, swallowed the US's biggest bedding wholesaler, Mattress Firm. A ballpark value for Steinhoff: R500-billion - a pile of wealth built up rapidly from very little by Jooste, who first got into the furniture business as a bean counter at GommaGomma, lounge suite purveyor to the 'burbs.Furniture and retail are his game. So is horse racing. Again, he doesn't do small. In a couple of decades he and his wife Ingrid have become the biggest owners of thoroughbred bloodstock in South Africa, by some margin, and are fast becoming players on the world stage too.Last weekend the Jooste horse ownership company Mayfair Speculators had a winner - called The Juliet Rose - at Chantilly at the Prix de l'Arc de Triomphe meeting. Those silks of emerald green jacket with yellow stars and black sleeves, so ubiquitous on our courses, are now being seen in most other racing jurisdictions.The Arc, regarded by some - mostly French - people as the most prestigious race in the world, was won by Found, a filly owned and bred by the Coolmore syndicate of the Irish Magnier family. Coolmore also owned the second horse home and the third.The Magniers do big.Later in the week, at the Tattersalls' Yearling Sale in the UK, a colt by Frankel - reckoned by many to have been the greatest racehorse of all time - was knocked down to a pair of bidders for 1.3million guineas. Guess who? A certain M Jooste and Michael Vincent Magnier, son of family patriarch John, aka "The Boss".Forging smart partnerships is Jooste's route to success. For example, he doubled his company's value by linking up with Christo Wiese's Pepkor.Now he's in bed with the most influential family in racing. How big can you go? Watch this space.If you need evidence of Jooste dominance of the local turf, glance at the card for tomorrow's Joburg Spring Challenge at Turffontein. No fewer than six of the 14 runners will be sporting the Mayfair colours.Among them are Durban July champ The Conglomerate. Alson Ndzilana, assistant trainer to Joey Ramsden, said this week the gelding wouldn't be fully wound up and his stablemate St Tropez was preferred.Of course, Mayfair has other trainers in the mix, so the other four horses must be seriously considered. Indeed, the likes of Deo Juvente, in the care of Geoff Woodruff, and Rabada from Brett Crawford's operation are very talented individuals.The problem with these and many others in this field, though, is that they are coming back after a period of rest and recuperation and this 1450m R400000 contest is just a preparation outing for bigger races later in the Highveld summer season.One horse that has already had his springtime pipe-opener - and won it in style - is Kangaroo Jack, trained by Gary Alexander. Here is a strange thing: the Joostes don't own a hair on his head.For all the yellow stars that'll be glittering out there in the Joburg sun, it might well be the orange and red silks of Joyce Wallace that make their way into the No1 box.That'll be disappointing for the bean counter, on a purely sporting level, of course. Despite all his dough and horses, young Markus never has a bet.MIKE’S SELECTIONS: Turffontein, tomorrow Race 6: 9 Hollie Point, 4 Crown Of Roses, 3 Olma, 2 Joan Ranger Race 7: 5 Kangaroo Jack, 9 St Tropez, 10 Bezanova, 2 Rabada..