The barn on Kamm Road just East of Lynden was already engulfed in flames when firefighters arrived just after 4 a.m. Wednesday.
More than two dozen firefighters were on the scene at one point as they struggled to contain the blaze.
Lynden’s Assistant Fire Chief Robert Spinner says the barn was completely destroyed, but firefighters kept the fire from spreading to other nearby buildings.
He says they couldn’t save the animals because there was too much fire. No people were hurt.
The Whatcom County Fire Marshall says the fire was caused by an electrical problem.