"One dog can do the work of six to eight men," he said. "And I have never had a dog call in sick on Monday. They are available rain, hail and shine, and they work for a bit of kibble, a few pats and affection."

Wilkinson was eight when he was transfixed by a stockman at the Easter Show who commanded his working dogs with a series of whistles.

When the 195th Royal Sydney Easter Show opened on Thursday, Mr Wilkinson launched a new show to demonstrate the old craft of dog whistling - not the political kind practised in Canberra these days.

Using nothing but whistles, his border collie cattle dogs - including Zac, Merle, Chime, Boo and Mambo - put cattle through an obstacle course and herded them to different parts of the arena.

"Zac," he called out, and then issued a quiet whistle that sent the black and white border collie running away. Another whistle, barely audible, brought the dog back immediately.

Each whistled command is personalised with a different tone for each dog.

So why whistle? "Because of the distance it can carry," replied Mr Wilkinson who works 13000 head of cattle on the Packer family owned Ellerston Pastoral Company located east of Scone, NSW.

"Where we are working every day, it is steep mountain country with thick timber," he said. "We whistle so it carries through the bush instead of voice commands. There is a left whistle, there is a right whistle, there is forwards, backwards and then there is another one to break out even farther to go after cattle."

Mr Wilkinson also breeds and sells working dogs that can handle stock in all conditions.

"Where I work is quite steep and thick country, and that's where these dogs excel because they can go and do their jobs by themselves."

His dogs are so well trained that even if he put a T-bone steak inside the front door, they wouldn't dare cross the threshold.

"You've got to set boundaries," he said.

They are strictly outdoor dogs, rewarded with lots of pats and motivated only by an innate love of rounding up animals. To discipline them, he issues a deep doggy growl.

The Farm Dog Survey, by Sydney University, found a working dog costs its owner about $8000 but does about $40,000 worth of work in its lifetime.

Mr Wilkinson said it wasn't feasible to employ many full-time cattle hands these days. "If you can send one dog one way, and another round the other way to get the cattle, that's two men you'd otherwise be using. "

For information about the Easter Show at the Showground at Sydney Olympic Park, visit http://www.eastershow.com.au/tickets-deals/