Fire crews remained on scene into the evening at a large barn fire across from the old Ford factory on Sunset Drive in Elgin County.
Ontario Provincial Police have confirmed that more than 80 dairy cows perished following the morning barn fire at Prikken Farm Ltd.
According to OPP Sgt. Troy Carlson about 100 cows are believed to have been in the barn with about 15 making it out unharmed. An early damage estimate is set at $1.5 million.
Southwold Fire Chief Gary Wilson said that tightly packed hay bails are tough to put out, and could take all day or longer to be fully extinguished.
The location is just past the point where Colonel Talbot Road turns into Sunset Drive, south of Highway 401, and a section of the roadway from Southminster Bourne to Clinton Line was closed due to the fire.
Crews responded to the fire shortly before 8 a.m. after several calls came in reporting the large blaze.
A column of smoke could be seen from Highway 401 and crews were forced to take defensive positions as the large structure was engulfed in flames.
Several cows could be seen on the property with workers herding them back from the fire.
Neighbours told CTV News that the owner of the farm was planning to head south on a vacation but had not left yet.
The cause of the fire remains unknown at this time and the Ontario Fire Marshal's Office has been notified.
String of fires in January
This fire is the latest in a series of barn fires in southwestern Ontario that have killed hundreds of livestock.
More than 2,000 pigs were killed in a barn fire in Parkhill, Ont. on Jan. 19.
That fire came just days after 500 goats and 30 cows died in a fire near Delaware, just west of London.
In the first two weeks of January, fires at two separate locations killed more than 50 horses and a third killed a number of chickens west of Listowel.