Image caption Australia is the world's largest exporter of goat meat

Hooves pound on metal slats as wild goats are loaded on to a lorry at an outback yard more than 700km (435 miles) west of Sydney.

No-one knows just how many goats are roaming the rugged expanses of the Australian outback, but feral herds have become part of a lucrative industry.

Australia is the world's largest exporter of goat meat, and suppliers believe the trade is about to experience a boom.

"I can see it doubling. It's just got that potential to keep growing - the amount of feral goats," says Tim Walmsley, manager of the Ausgoat depot near Cobar in New South Wales.

Image caption Tim Walmsley from Ausgoat in Colbar: New South Wales has a population of up to two million goats. There are a lot of people making a living out of [goat meat] Tim Walmsley, Ausgoat depot manager

"They say the Western division of New South Wales has a population of anywhere between a million and two million goats. It's a huge number of goats that can be supplied,"

The yard is a short drive from a town famous for its copper mines, and the road snakes through the bush and the distinctive red dust.

A flash of white hair in the scrub reveals a small mob of wild goats foraging for food. These hardy animals arrived with the first European settlers, and they've adapted well to Australia's harsh, dry conditions.

Around the world, goat milk, hair and skins have been used for centuries, and Australia is at the heart of the global trade in meat.

The Ausgoat processing centre on the outskirts of Cobar handles 100,000 animals every year.

Image caption Up to two million goats can be found across Australia's dry and rocky areas

The latest skittish group pace nervously in a small pen. These are youngsters, about 10 months old, that will end up on dinner tables in Sydney, Brisbane or an Asian city far beyond Australia.

Feral goats in Australia Can be found across 28% of the country

Most common in the rocky or hilly areas

High reproductive rate

Populations able to increase by 60-75% a year

Relatively free of diseases due to dry Australian environment Source: Australian Veterinary Association

In the next compound are larger billies capable of breaking bones or even killing cattle dogs.

Feral goats are considered pests that poach valuable water and food from livestock.

They are usually caught by farmers, often in traps by waterholes, or are mustered on larger properties using gyrocopters or planes, and will be carted off to abattoirs around the country.

The meat is either sold to domestic consumers or to a growing international market, particularly in Asia.

"There is money to be made in it. It is also a big industry. There are a lot of people making a living out of it," Mr Walmsley says.

Media playback is unsupported on your device Media caption Australia's goat exporters predict the market is set to boom

"I'm here, then we've got a truck driver that comes and gets them, then you've got the processor, the abattoirs - they're all making a living out of it. Everybody gets a fair share."

We've seen recent export orders from Malaysia, China, Korea and the Philippines Joe Portelli, Livestock sales specialist

There is also a thriving trade in farmed animals. On a property near the town of Orange, a small herd of meaty specimens roam.

These are Boer goats, a robust variety brought to Australia from South Africa in the 1980s. They are part of a profitable business sending live exports to Asia.

"We mainly sell to Malaysia and Thailand, but our goats mainly go for breeding, so the people who come here to look at my animals are looking for a good quality stud animal that will fit into what their breeding programme is in Thailand or Malaysia," saya Christine Andrews, who runs the farm with her husband Ron.

Fame and Goddess are keys to the success of this family-owned enterprise. These are breeding does, or nannies, that are treated almost like pets.

Image caption The Boer goat, with its distinctive brown head, is one of the most popular types of goat bred for its meat

Each has a name: Grace was a champion at a local show, and there are high hopes for Britannia and Japonica.

Their offspring will eventually be sold overseas, most probably to build up herds in Asia.

Other popular markets for live exports include Singapore and Brunei, but it is the multi-million dollar trade in meat that has risen sharply in recent years.

Australia's goat exports have doubled in the past decade. While much is sold to the United States and Taiwan, there is a growing appetite elsewhere in Asia.

Image caption Joe Portelli says the recent fall in the Australian dollar has helped revive orders from customers in Asia

"In recent months the Chinese have shown a great interest," Joe Portelli, a livestock sales specialist based in western New South Wales, told the BBC.

"We've seen a lot of Chinese come to our market in Dubbo. We run a sale there every three months. We've seen a lot of Asians come to that, especially the Chinese,"

A weakening of the Australian dollar in recent months has also helped to boost global sales.

"The meat trade seems to have picked up since the dollar's come back down a little bit," Mr Portelli says.

"We've seen recent export orders come in from such countries as Malaysia, China, Korea and the Philippines, and those orders have just lifted the price of the goats up astronomically.

"It just seems to be getting bigger and bigger each week, each month and each year."

The industry has had its problems with inconsistent supply and quality, but goat suppliers here insist that their animals are among the best in the world, and that exports are boosting not only the Australian economy but are helping to feed an ever hungrier Asia.