The fire broke out at Tolmie and Number 2 Road shortly after 6:30 a.m. PT Sunday.
At its height thick smoke could be seen billowing over neighbouring fields from several kilometres away.
The barn's roof was partially caved in. Most of the structure was completely destroyed in the fire.
It's not known whether all the cows were saved.
More to come
Google Map: Tolmie and Number 2 Road, Abbotsford, B.C.