By Colin Packham

SYDNEY (Reuters) - Mustering cattle across rugged terrain and wide open spaces, Australia's newest drover is a far cry from a man with a big hat, a horse and fancy boots.

Meet SwagBot - the world's first robot designed to round up livestock - currently being developed by Australian scientists to roll across the landscape in aid of the country's farmers.

Australia is the world's third largest cattle exporter but with the age of producers creeping higher, and cattle stations averaging about 400,000 hectares (988,420 acres) of land - nearly four time the size of Hong Kong - rearing livestock can be difficult, even with a sufficient number of cowhands.

A labor shortage makes the task harder though, and threatens Australia's hope of boosting its livestock output to profit from rising Asian demand for red meat.

SwagBot is the answer, according to Professor Salah Sukkarieh, who heads the research team developing the robot.

The contraption - a box of electronics supported by four independently moving legs attached to wheels - is omnidirectional, navigates over obstacles, even across water, and can be remotely controlled by farmers as it herds cattle.

"[Farmers] can see that they need to have this kind of technology. We aren't seeing a lot of people coming into the sector as it is a lot of work," said Sukkarieh, a professor of robotics at the University of Sydney's School of Aerospace Mechanical & Mechatronic Engineering.

Additions to SwagBot's capabilities are also planned. It will soon have sensors that can detect pasture health and determine if an animal is sick or in distress.

The robot - one of a growing number of automated vehicles designed for the country's rural sector - remains in development, but Sukkarieh believes it can be in production within three years.

"Maybe about five to eight years ago, the cost of technology dropped quite significantly," he said. "Because of that drop in cost, agriculture has opened up as another area where robotics could be used because there are very low margins in agriculture, so you need low-cost robotics."

Technology offers the best hope to arrest Australia's slowdown in agricultural productivity, analysts said.

"Getting good, reliable labor is a problem, and the further you get away from a capital city, the harder it gets," said Phin Ziebell, agribusiness economist, National Australia Bank.

"If the robot can be cheaper than humans, too, farmers will be very keen."

(Reporting by Colin Packham; Editing by Tom Hogue)