The incident happened last week during a thunderstorm on the Wielgosz family farm near the hamlet of Yellow Creek, which is about 120 kilometres north of Saskatoon.
"It was a pretty intense thunderstorm ... lightning and wind and rain," Stephen Wielgosz told CBC News.
The 18 cattle were in a pasture at the time, and after hearing the thunder, they apparently huddled under a tree. A bolt of lightning struck the tree, killing them.
Wielgosz said he found a terrible scene when he went out to investigate. "They're actually all in a pile," he explained.
"They must have been laying around a tree," he said. "You can actually see the streaks that the lightning did go down the tree and amongst them."
The Wielgosz family is trying to deal with the loss. The cattle were valued at about $40,000. He says he had no insurance on them, but is looking into options for his surviving cattle.
Now, every time a storm passes through, he worries.
"I hope it never happens again," he said.
Also on HuffPost