A dairy farm in western Wisconsin has won a $4.5 million jury award after a five-year legal battle with Xcel Energy over the effects of "stray voltage" on its cows.

Earlier this month, a Trempealeau County jury sided with Galesville, Wis., farmers Paul and Lyn Halderson, who claimed stray voltage from power lines hurt their 1,000-cow herd, decreasing milk production. The Haldersons are asking a state court for triple damages, which could increase their award to $13.5 million — a huge payout in a stray-voltage case.

"Even $4.5 million is large," said David Sienko, an attorney for the Haldersons in River Falls, Wis.

Xcel can appeal the verdict. The Minneapolis-based company said in a statement that it is "disappointed with the decision and will be evaluating next steps."

Stray voltage refers to electrical currents that leak into the ground; farms can then become part of a circuit path. Water troughs and milk machines, for instance, can conduct stray current, delivering mild shocks to cows.

Farmers say cows eat less and drink less as result of such shocks. Utilities claim that electricity conducted into dairy cows isn't enough to harm them.

The stray-voltage issue has been around in dairy country since at least the 1980s, and in recent years two cases in Minnesota have led to large awards to farmers.

Last year, the Minnesota Court of Appeals upheld a $9 million jury verdict against Crow Wing Cooperative Power and Light Co., the largest such award in Minnesota and one of the biggest nationwide. The plaintiff operated a dairy farm in the northern Minnesota town of Pine River.

In 2013, the Minnesota Court of Appeals upheld a considerably smaller jury verdict favoring a Waverly farmer in a stray voltage case against Wright-Hennepin Cooperative Electric Association.

In the Haldersons' case, a jury in Trempealeau County Circuit Court found that Northern States Power — an Xcel subsidiary — was "negligent with respect to the delivery of electrical service." The jury awarded $4.09 million for economic damages and another $409,000 for "inconvenience, annoyance and loss of use and enjoyment" of property.

The jury also decided that Xcel's failure to provide adequate electric service was done in a "willful, wanton or reckless manner." Under Wisconsin law, a willful and wanton determination calls for tripling damages, Sienko said.

The Haldersons filed suit into 2012 against Northern States Power, a subsidiary of Xcel, attempting to recover lost profits from 2004 to 2011. The couple had called NSP multiple times in previous years, suspecting stray voltage was hurting their cows — but the utility found there was no problem, Sienko said.

The farm then hired an independent electrical investigator who concluded that stray voltage was a problem.

The Haldersons requested in 2011 that Xcel put in place certain equipment on the farm to halt stray voltage. Wisconsin utility regulations call for Xcel to honor such a request, though the Haldersons paid for the equipment, Sienko said. It solved their stray-voltage issue.