Singapore authorities are investigating why 174 sheep imported from Australia for today's korban ritual to mark Hari Raya Haji died during the flight from Perth.
Close to one in 10 of the 2,200 sheep were dead on arrival after the five-hour flight landed here on Thursday.
This was the first time so many deaths had occurred in such a consignment, said the Islamic Religious Council of Singapore (Muis).
The Agri-Food and Veterinary Authority of Singapore (AVA) is examining the carcasses, while the Singapore Mosques Korban Committee (JKMS) is working with transporter SIA Cargo to investigate.
Korban - the Islamic ritual commemorating Prophet Ibrahim's obedience to God because of his willingness to sacrifice his son Ismail - is expected to go on as planned today.
The shortfall in sheep has mostly been made up for by extra lambs out of the 1,700 imported from Ireland.
Another 59 came from a buffer in the supply numbers. The animals from Ireland were priced at $575, while the ones from Australia cost $499.
More than 3,000 animals went to 26 mosques and organisations for the ritual, after which the meat will be distributed to family, friends, and the poor and needy.
AVA, which inspected the sheep and sent several of the carcasses for post-mortem, has ruled out the possibility of infectious disease, which could constitute a health risk to anyone eating the meat.
The flight time was too short for such diseases to take hold and spread, and the remaining animals were healthy and had passed quarantine, explained Dr Yap Him Hoo, group director of AVA's quarantine and inspection group.
"Clear signs" such as organ haemorrhage indicated that heat stress was the likely culprit, he added.
Two years ago, new livestock rules in Australia required exporters of livestock meant for slaughter to comply with internationally accepted animal welfare standards.
Mosques in Singapore had to prove that they met those standards, including giving each animal at least 0.6 sq m of space in its holding pen, and getting only trained, appointed personnel to carry out the slaughter.
Minister-in-charge of Muslim Affairs Yaacob Ibrahim said on the sidelines of a seminar at the Lifelong Learning Institute that Singapore had begun to diversify its supply of korban animals to reduce the impact of incidents like Thursday's.
"Last year, we experimented with a small supply from Canada and a slightly larger supply from Ireland this year," he said. "In so doing, we can minimise the risk of such unexpected events."
This article was first published on Oct 5, 2014.
Get a copy of The Straits Times or go to straitstimes.com for more stories.