The following correction was printed in the Guardian's Corrections and clarifications column, Friday April 20 2007





The padlocked freezer at Xiongsen Bear and Tiger Mountain Village attracts little attention from the tourists who throng to the park each day.

Most are more interested in the bloody spectacle of tigers savaging live cows, the monkey bicycle race or the highwire displays by bears and goats. But it is the freezer rather than the freak shows that will soon be at the centre of a fierce international debate on the trade in endangered species.

Xiongsen is the world's biggest battery farm for rare animals. Located just outside the southern Chinese city of Guilin, it is smaller than Regent's Park but holds 1,300 tigers - almost as many as the whole of India - as well as hundreds of bears, lions and birds.

The stock is worth hundreds of millions of dollars in China, where consumers pay high prices for remedies, tonics and aphrodisiacs made from rare species. But until now the park has only been able to bank its assets in cold storage because of a ban on tiger products.

All that could be about to change. After a decade of lobbying by Xiongsen, China is preparing to call for a lifting of the ban. Next week it will send its first ever delegation to the Global Tiger Forum in Kathmandu. In June, at a conference in the Hague of signatories to the Convention on the International Trade in Endangered Species (Cites), it is expected to push the issue. In a paper to Cites, China says the global ban has failed to halt the decline of the wild tiger population, despite a cost of £2bn to the Chinese economy and damage to China's traditions and medicinal culture.

Conservation groups warn that relaxing the ban could be disastrous. According to the World Wildlife Fund there are only 3,500 tigers left in the wild, compared with more than 6,000 in captivity. "This move could mean the end of wild tigers for China and could mean the extinction of many other tiger populations in Asia," said Grace Gabriel, Asian regional director of the International Fund for Animal Welfare.

In China the transformation of this jungle predator into a caged farm animal is even more dramatic. From several thousand in the 1950s there are now only 50 left in the wild. The Amur tiger of north-eastern China is the most threatened subspecies in the world. The captive population has exploded - at Xiongsen alone it has surged from 12 in 1992 to 1,300 today.

To conservationists, though, it is anything but a success story. Hu Hongfu of Traffic, a monitoring group linked to the World Wildlife Fund, says the park is breeding more tigers to blackmail the Chinese government and the international community. "Xiongsen is the worst of the tiger farms. It is run by individuals who breed for money. We have advised them to stop because more tigers means more problems, but they keep breeding because it puts pressure on the government to lift the ban."

Monkeys on camels

The park is part farm, part zoo and part circus. Its nursery is the start of a production line that churns out hundreds of tigers each year and ends in the freezer packed with carcasses. In between, most animals spend their lives in hundreds of tiny cages that are lined up in rows around the perimeter wall, each jammed with as many as four animals, which lie around listlessly or pace back and forth between wire and concrete.

More fortunate beasts share a few football pitch-sized enclosures in the main visitor area. Others are trained to perform in the Dream Theatre - a circus where they jump through flaming hoops - or in an outdoor show that also has monkeys riding camels and a bear cycling across a highwire without a safety net.

For most of the hundreds of tourists who come each day the most memorable part of their visit is feeding time, when a tiger is released into a pen with live cattle. Earlier this week tourists gasped but watched in fascination as the predator chased down a cow, sinking its teeth and claws into its victim, which cried and defecated in pain and fear.

The bloody spectacle lasted 15 minutes before the tiger - too domesticated to kill its prey in such a short time - meekly returned to its cage and the wounded cow was taken away for slaughter by zookeepers. Guides say the mini-hunt is exercise for animals that will one day be released. But this is dismissed as nonsense by conservationists, who say no animal from Xiongsen will ever be fit for the wild.

"This is a farm that speed-breeds as many tigers as possible so that they can make them into products for sale," said Ms Gabriel. "Their genetic purity is compromised. If they were mistakenly released into the wild they would pollute the wild population."

A keeper still with blood on his hands from dragging the wounded cow to the abattoir said the park was hoping for a resumption of the tiger trade. "Every part of the animal is valuable, but we can't sell them at the moment because it is forbidden by law. One or two tigers die every year. We put them in freezers, where they will stay until the government gives us permission to sell."

The business-first philosophy of the park is evident everywhere. The restaurant offers a dish of "conquering king" - the classical term for tiger - for 500 yuan (£33), along with lion, crocodile, peacock, snake, bear and civet cat. "Everything comes from our park," said the waitress. "We don't say what the ingredients are. You must use your imagination." But the ban has clearly hurt the park. The keepers say they struggle to get by on monthly income of 500 yuan - less than most migrant labourers earn in factories or building sites. Office managers say they have not been paid for more than three months.

"The ban has really hurt our business," said Bai Wenqiang, the sales manager. "Our boss's original plan was to make a park that would sustain people's health, keep more tigers alive and help the environment. But since we started we have lost 400m yuan."

"We believe international law allows trade in animals that have been reared by man for three generations. It is only the domestic law that prevents us now. We understand the Chinese government is under a lot of international pressure. They don't help us. But they don't give us trouble."

Backstory

China has been using tigers for medicinal purposes for 5,000 years and a single animal can be worth hundreds of thousands of pounds. The bones, used in tonics, are the most valuable part: the 25kg (55lb) yielded by the average tiger can fetch 2.4m yuan (£160,000), about 10 times the price of a pelt. At the Xiongsen park, sales assistants proffer tiger-shaped bottles of bone-strengthening wine for about £60. Each drop, they claim, is distilled in vats containing the paws of the animal, which - if proven - would be a contravention of domestic and international law: China banned the sale of tiger products in 1993. Tigers are not the only exotic species prized for medicinal value. A shop in Guilin showcases desiccated seahorses for breast cancer, dog penises for virility, deer hooves for arthritis, baby snakes for sore throat and ant lotions for beriberi. One rheumatism medicine has a picture of a tiger on the packet, but the only animal ingredient listed is powdered leopard bone.