Mapleton Fire and Rescue was called out to a cattle barn fire near Alma on Sunday morning around 9 am.
On arrival crews found the barn was fully involved.
The barn was found to house around 110 cows with 40 perishing in the fire and 70 rescued from the building.
The blaze saw 60 firefighters attend the scene with assistance from Wellington North and Minto Fire as well as tanker support provided.
There were no injuries to civilians or firefighters reported.
The fire was found to have originated in the second storey of the barn and the cause is yet to be determined.
The damage is set atver 1 million dollars.
