The Jackson County jury found Susan Monica guilty of murdering two men about a year apart, then abusing their corpses by feeding them to the animals at her farm, The Medford Mail Tribune reported.
Circuit Judge Tim Barnack immediately sentenced Monica to a minimum 50 years in prison.
"You shot two people and fed them to your pigs," the judge told Monica, 66. "I don't know how else I can put it. You valued pigs more than you value people.
"It may sound harsh, but you are a cold-blooded killer," Barnack said.
Prosecutors said Stephen Delicino, 59, was killed in 2012 and Robert Haney, 56, died in 2013.
Monica asked for sentencing as soon as the jury was dismissed, saying "it doesn't seem to matter."
The case will be appealed, the defense said.
Monica's changing stories about how she shot Delicino and Haney never matched the forensic evidence, Allan Smith, senior assistant deputy district attorney, told jurors in closing arguments.
She variously claimed that Delicino shot himself repeatedly in the head and also that she shot him in self-defense and he was eaten by her pigs before she buried his remains on her 20-acre farm in southern Oregon, Smith reminded jurors.
Monica told investigators Haney disappeared in the summer of 2013. She said she came on him a month later as pigs were disemboweling him, and she shot him to ease his suffering. She later questioned whether he was alive when she shot him.
Defense attorney Garren Pedemonte argued there was no concrete evidence to rebut Monica's claims that she shot Delicino in self-defense or to show that Haney was actually alive when Monica shot him. Some of his remains were found in plastic bags in her barn.
A State Police forensic anthropologist, Veronica Vance, testified that Haney's legs had been chopped off with an ax, and the thigh bones showed signs of being gnawed by an animal.
Vance said she couldn't determine whether the ax blows came before or after Haney died. She said Delicino suffered three to four gunshot wounds to the head, but there was no evidence one way or another about the self-defense claim.
"Just because Susan Monica is different and strange and weird doesn't make her a murderer," another defense lawyer, Christine Herbert, told the jury.
At one point during the six-day trial, Monica herself cross-examined sheriff's Detective Eric Henderson, who was the lead investigator in the case, despite having her own defense team.
On Monday, a cellmate of Monica's testified the defendant signed a birthday card in jail with this phrase: "from the sweetest murderer in Jackson County."
"I got chills from the birthday card," 23-year-old inmate Jordan "Janae" Farris testified. Farris was serving time for violating probation from a burglary conviction and met Monica in the Jackson County Jail.
Monica said she signed the card in accordance with the charges she was facing, KDRV-TV reported.
As the judge addressed the jury before deliberations Tuesday, the newspaper reported that Monica stood up, raised her hand and began asking for the chance to give jurors one more demonstration on how she claimed she shot Delicino.
"I'd like to demonstrate how I shot him for 10 seconds," Monica said.
Barnack initially ignored her. Then Monica put her hands in the air, as she did in her earlier testimony from the stand, and said, "I held the gun like this."
At that, the judge ordered her back to jail and sheriff's deputies took her away.