"Goats wouldn't have seen a tiger from an evolutionary point of view for at least 15 generations but they recognise the smell of the predator," repellent creator Peter Murray said in a statement.

"If we can show this lasts weeks ... we've just tapped into probably a billion-dollar market. It's enormous," he said.

Murray said the repellant, made of fatty acids and sulphurous compounds extracted from tiger excrement, also worked on feral pigs, kangaroos and rabbits and might deter deer, horses and cattle too.

In an average year pest animals cause about A$420 million (US$311 million) worth of agricultural damage in Australia the government has said. Others put the cost in the billions, mostly from European imports such as rabbits, foxes and crop-choking weeds.