An exceptionally harsh winter in Mongolia is devastating livestock in several provinces and has wiped out some herds on which nomads depend.

At least 626,000 head of livestock have been reported dead and thousands more are dying daily.

In the central Gobi province alone, 250,000 head of livestock have perished.

"I have lost all my animals. I don't have even a single cow to get milk for myself," said 77-year-old Tserennadmid, who like many Mongolians uses only one name.

"I don't know how I will manage now," she said in a felt tent surrounded by dead cows and sheep.

Aid appeal

Mongolian President Natsagyn Bagabandy warned: "Animal husbandry, the fundamental basis of our economy, is facing a serious danger of being destroyed."

He has made an address to the nation, calling for unified efforts to help livestock breeders.

The government has appealed for aid from home and abroad.

Officials said hay was being sent to some provinces, but some nomads said no aid had arrived.

'From bad to worse'

Douglas Gardner, the head of the United Nations Development Programme in Mongolia, said that the situation is likely to get worse for the country's cattle herders.

"The problem is when they lose the herd there's not a safety net and insurance to back them up," he told the BBC.

"It has been devastating so far and our concern is that it may go from bad to worse during the remaining months of the winter and as we enter spring."

Mongolia's economy relies heavily on its 33.5 million livestock, which normally graze on snowless pastures even during the coldest months of winter.

In addition to the unusual snow, herders are also suffering from the effects of a summer drought which cut the hay crop. Spring does not arrive until late May or early June.

Millions of horses, cattle, yak, camels, goats and sheep are without sufficient fodder in vast areas under deep snow in northwestern, central and southern parts of the country.

Newly-born calves are now in danger of dying in the extreme cold.