COPAKE, N.Y. (AP) — The widow of a New York dairy farmer who methodically slaughtered 51 cows before taking his own life says she wants to figure out a way to keep the farm going.

Dean Pierson, 59, was found dead Thursday on the floor of his barn in Copake, a rural hamlet 115 miles north of New York City. Nearby, half his herd lay in their milking stalls, also dead of gunshot wounds.

Pierson left no explanation for what he'd done, just a simple note on the barn door warning whoever found it not to come in and to call the police.

But there appeared to be a method to his bloody work. He killed only the cows that required frequent milking, letting 50 others live, including heifers and calves.

Neighbors speculated that he was trying to spare his family the burden of caring for the animals.

He left no suicide note, said his wife, Gwynneth, who was home at the time of the shootings but heard nothing.

"No one knows why for sure," she told the Times Union of Albany, adding that her husband had been "talking a lot to his mom."

Now, she said, "We need to figure out how to keep the farm going ... It wouldn't be right for all that work he put into it to go to nothing."

On Friday, neighboring farmers used a backhoe and bulldozer to bury the animals, pushing them into a deep pit in the Columbia County soil.

Pierson had four children, but he milked the herd alone — once before sunrise and again at night, neighbors said. He kept mostly to himself, rarely visiting with other farmers.

"Dean had no help on the farm and he worked really hard to do it all himself," neighbor Susan Kiernan told the Times Union.

"It's hard to hang in now and a lot of dairy farmers are going out of business," she added. Kiernan's family has operated a dairy farm for three generations.

The gruesome scene in the barn was discovered at about 1 p.m. Thursday by a neighboring farmer

State police Capt. Scott Brown told the Rockford Register-Star that an investigation revealed that the farmer was having "personal issues."

The farm was founded by Pierson's father, a Swedish immigrant. He named the property High Low Farm.

Copyright 2010 The Associated Press.