Field of dreams: How do trainers prepare a horse for the Grand National?

Gary Cansell reports from an elite stable

Assistant trainer Johnson White hops into the tractor bucket in the soft morning light. He is lifted up in the bucket to within reach of a clock nailed above the barn door, which he adjusts to read 7am. British Summer Time has begun at Sandhill Racing Stables in Bilbrook, Somerset.

Spooked by the sight of White rising into the air, the horse nearest the door stops yawning and shoots to the rear of his stall. Amid flecks of dust and hay, his neat chestnutfringe is worried into a crude side-parting.

"He's not used to seeing me in the bucket," says White, the second-in-command here at Sandhill. "They're fragile animals, only seconds away from disaster every step of the way. It's our job to avert that disaster."

White strides into the tack room, to orchestrate the day's activities. He hunches over a magnetic board and aligns tiny metal strips. Some bear names, others types of exercise. Back in the barn, Matt Griffiths issues a soothing word to the nine-year-old gelding – named Dream Alliance – and settles him immediately. "I've been looking after this fellow this season," says Griffiths, an amateur jockey and at 19 already a member of the the stables' staff. "He's laid-back, sensible – too clever; but my easiest horse by far."

On 10 April, alongside 39 other horses, Dream Alliance will compete in the 2010 Grand National at Aintree, Britain's most punishing steeplechase; two years ago, it almost killed him. Sandhill-trained horses have accumulated close to £1m this year alone, but Aintree success has eluded them. Should Dream Alliance change all that, it will cap a remarkable story that began 10 years ago in a working-man's club in Cefn Fforest, an old Welsh mining village near Blackwood, Gwent.

The club's manager, Jan Vokes, was pulling pints one night when a man named Howard Davies and his brother entered. They began sharing memories of a racehorse that had belonged to them – and lost them money – 20 years previously. Vokes listened to their conversation carefully. "The thought of owning a racehorse had never entered my head before hearing that conversation," says Vokes, although she had previously bred prize-winning pigeons and whippets with her husband Brian. If she bought a mare and bred a foal, would Davies organise a syndicate? "He was reluctant; he said his wife wouldn't be pleased. But I pursued the matter."

Now working as a cleaner at Asda, Vokes and her husband paid £350 for Rewbell, a 13-year-old mare. They then stumped up £3,000 for a breeding of their mare with a stud named Bien Bien. Dream Alliance was the result, born in March 2001. He was reared on a disused allotment – vegetables wouldn't grow there – on top of an old slag heap. Asked whether that arrangement was unique, Vokes giggles: "It's not common." White, a trainer at Sandhill for 15 years, adds: "Normally owners who can spend big money on horses win the big races. It's fantastic that it can be done on a shoestring. It gives everyone hope."

After four years what had become a 22-strong syndicate – including a painter/decorator and a noodle-factory worker – sent Dream Alliance to ex-jockey and renowned trainer Philip Hobbs at Sandhill, paying £10 each per week for the privilege. Surrounding a grand Elizabethan manor house, the stables nestle in 500 acres of patchwork farmland owned by The Crown Estate. From certain vantage points you can see across Bridgwater Bay on the Bristol Channel, to the Welsh coast.

The day begins with Griffiths mucking out one of the three stalls that he cleans twice a day. Forkfuls of straw and manure arc into a wheelbarrow. Dream Alliance stands motionless. He is a breathtakingly beautiful animal: his legs look as though they've been dipped in a pot of white paint; his nose is smudged with alabaster; the rest of his coat is the colour of a gingersnap biscuit. "Dreamy doesn't move much throughout the day," says Liz Welsh, one of two head girls who monitor and maintain the health of the stable's 112 racehorses. "Come on boy," whispers Griffiths. Dream Alliance shuffles obediently into the stall's cleaner half.

Philip Hobbs hopes the world's most lucrative steeplechase goes as smoothly for this fabled horse. "If he produces to the best of his ability, he'll have a good chance. But he can be inconsistent," the trainer warns. "His last run wasn't great, but he has bounced back before. Hopefully he'll do it again." Jan Vokes, though, is optimistic, not least because of her gelding's unlikely triumph in the Welsh National at Chepstow last December. He had been overlooked by Sandhill's number one jockey, Richard Johnson, who took the in-form Kornati Kid (for whom a burst blood vessel ended the race early). It was the stable's number two, Irish-born Tom O'Brien, who rode him to victory, and will partner him again at Aintree.

"There was a 'thing' in the yard over which horse was better," says stable hand Clare Sandercock, who rides Dream Alliance during training. "I always said [Dream Alliance] was better, and he was. He's a perfect gentleman to ride, very laid-back. He likes things his own way, but he does listen."

The Welsh National victory marked an astonishing comeback: four jumps from home in the 2008 Grand National, Dream Alliance hit one of the race's infamously tall fences, slicing a tendon. His life was spared but his career appeared to be over. To save the horse, Liverpool vets performed ground-breaking stem-cell surgery costing £20,000 – a figure the syndicate paid without hesitation, using their prize money.

The investment could well pay off; should Dream Alliance nose home first on Saturday, he'll net a staggering £521,052.

As the day approaches, Vokes is excited and nervous in equal measure. Thirty fences stretched over four and a half miles is a gruelling endurance test, and of the 40 runners, many won't finish. Since 1999, eight horses have died during the race. Improved safety records have not mollified the animal rights activists campaigning for its ban. "It doesn't matter how good your horse is," Vokes adds, "it's still scary."

Regardless of the outcome, a Welsh film director Justin Golding, now based in the US, has signed a deal with the syndicate to tell the story of its beloved horse.

Days before the race, Dream Alliance remains a picture of equanimity, dappled in the light that breaches the barn walls.

"Pull out!" White bellows from the yard.

Each day, Sandhill's horses are exercised, the first batch going out at 7.40am. Clare Sandercock leads Dream Alliance from the barn to join the second group. Thirty horses slowly circle the yard as White scrutinises them for signs of injury. Satisfied, he dispatches them to the polytrack – an all-weather surface two and a half furlongs (500 metres) in length.

The horses congregate at the bottom of the track and run back and forth, in pairs. There goes Rebel Dancing, County Zen, Captain Chris. With every stride they suck air greedily. Hooves pummel the ground, peppering the sky with clods of synthetic earth. Dream Alliance gallops alongside charcoal-coloured Lacdoudal; veins stand out on muscular flesh.

The over-zealous horses are better off running single-file. "Otherwise they would try to outdo each other," explains White explains. "We don't want them doing too much on a daily basis."

Exercise over, the riders circle a grassy knoll at the top of the track. A fine rain begins. His tweed cap pulled down, White paces alongside them, asking each: "OK?"

"Bit scratchy," says one.

"Bit slow," says another.

"Yeah," nods Sandercock.

For the paunchier horses, it's into the swimming pool for six laps. The horses are "completely pampered", says White. Along with world-class facilities, staff, feed and supplements (cod liver oil is a favourite), "everything" includes weekly visits from Mary Bromiley, physio- therapist for New Zealand's equestrian squad at the last four Olympics, who massages those with sore bits.

Sandercock plunges an orange sponge into a black bucket and washes Dream Alliance outside the barn. She brushes and dries him, then it's back to the stall for a lunch of high-protein nut pellets. He eats more than 8kg of them daily, and is fed at 6am, 1pm, 5pm, and finally by two night staff at 9pm. Everyone else clocks off at 5pm, having started the working day at 7am.

Every Monday after lunch, 10 boys and 10 girls take it in turns to march the horses onto weighing scales while White scribbles their statistics into a notepad. Dream Alliance takes his turn on the scales. The digital display scrolls to 502.5kg – his ideal race weight (though he ranks among the heavier Aintree competitors). That weight will remain constant until May, when he is put to grass for three months. "They chill out through the summer," Johnson says. "Like humans, they need a break." Without an exercise regime, some horses return carrying an extra 70 kilos.

Evening approaches. Carol Burnett, Sandhill's other head girl, checks Dream Alliance's shoes and legs and ushers him back to his stall, where he'll remain until tomorrow morning. A stable hand delivers a bucket of hay and pauses to stroke him; the horse's large head rolls luxuriously to one side. He thrives on attention, says Sandercock. Jan Vokes agrees that there is a hint of celebrity about him.

"He loves the cameras," she laughs. "He poses for them, a real show-off. He would've been a model if he hadn't been a racehorse." According to Hobbs, however, Dream Alliance is "very straightforward".

"We don't treat the horses like animals," explains pupil assistant Darren O'Dwyer, later that day. "We treat them like people. Dream Alliance never shows what he's thinking. He'd be that kind of person, too."