Authorities are investigating the circumstances behind the deaths of 20 to 25 cattle found on a western Wisconsin farm and speculate that some may have been killed by stray electrical voltage.

Barron County Sheriff Chris Fitzgerald said Friday that an Xcel Energy worker operating on a farm near Almena discovered the cattle last week and reported them.

“It basically was a pile of cows,” Fitzgerald said, estimating there were about two dozen dead animals, some of them partly decomposed. “He saw the pile and said, ‘This doesn’t look right.’ ”

Fitzgerald said the cows had died over the winter because of illness, harsh weather and possibly stray voltage.

An Xcel spokesman, however, said that stray voltage wasn’t a factor.

“All of our equipment was operating normally,” Matt Lindstrom said Friday.

Fitzgerald said the farm owners had planned to bury the animals but had been waiting for the ground to thaw. The farmers are cooperating with the investigation and no charges are expected, the sheriff said, adding that he didn’t know if the cows were dairy or beef cattle.

Other cattle on the farm were healthy and well cared for, Fitzgerald said. They have been moved to another farm “until the stray voltage issue can be looked into and corrected,” he said.