Mass sheep death on export plane

The death of 174 sheep on an export cargo plane due to a ventilation failure is being investigated by Singapore Airlines.

The sheep were part of a 2000-head consignment travelling from Australia to Singapore last Thursday for the Korban festival - where goats, sheep, cows and camels are slaughtered on Eid Al-Adha day.

It's believed the sheep were from Western Australia.

Australian Livestock Exporters' Council chief executive Alison Penfold said the deaths were rare, upsetting and regrettable.

"It is understood that there was a ventilation failure on the aircraft, but we await the investigation report," she said in a statement.

The exporter reported the incident directly to the Department of Agriculture in Canberra early on Friday, she said.

The reportable level for air-transported sheep is two per cent, or three sheep - whichever is greater.

High mortality flights for sheep have occurred seven times in the past seven years.

Between 2008 and 2013 the total number of mortalities of sheep, cattle and goats amounted to 340 out of 624,942 animals exported by air, Ms Penfold said.