A third of Mongolia's population relies on animal herding
Extreme cold in Mongolia has killed so much livestock that the United Nations is starting a programme to pay herders to clean and collect the carcasses.
More than 2.7m livestock have already died and another 3m carcasses are expected by June.
The UN Development Programme cash-for-work programme aims to produce income for herders whose livelihoods have disappeared due to the weather.
Concern is high for the risk of disease posed by piles of rotting dead animals.
Once melting of the snow starts, this poses the threat of the spread of diseases such as anthrax and salmonella, infection and soil pollution.
Persistent snowfall has created a blanket of snow over the entire country, with 60% covered by 20-40cm (8-16in) of snow, the UNDP says.
Mongolia has been hit by an unusually harsh winter
This year is particularly harsh because of a phenomenon called Zud, which occurs when severely cold winters of below -50C (-58F) are preceded by dry summers that preclude sufficient grazing.
Fodder supplies have run out, resulting in the loss of millions of livestock in a country where a third of the population rely on herding and agriculture, the UNDP said.
The livestock affected include goats, sheep, horses, camels and cows and yaks.
The government of Mongolia requested $4m (£2.6m) for cleaning up the carcasses. Various UN agencies are being asked for the funds.
"While immediate needs of food, shelter, heating and health care must be met, this approach also helps herders to feed their families during the Zud," said Akbar Usmani, a UNDP representative in Mongolia.
"Livestock is the cornerstone of existence for so many Mongolians and many people have lost all their direct income and food source."
The last devastating Zud was in 2001.
About one third of the population lives below the poverty line in Mongolia, a figure that is expected to rise due to the massive livestock loss.
The UN said 19 of Mongolia's 21 provinces had been hit by heavy winter snow and -40C temperatures.