The 32-year-old from Fitzlar-Haddamar smashed his father's head open in 2000, and four years later strangled his mother, inventing stories to explain their deaths to the authorities.
He told officials his father had been kicked in the head by a sick cow, and then later said his mother had died in her sleep.
In 2005, an elderly farm worker who died at the farm of natural causes, but the man did not report his death, rather cutting up the body and feeding it to the pigs in order to claim his pension.
The events came to light when the farmer faked a funeral of the elderly neighbour.
He told officials he was not prepared to wait until his father died naturally so he could inherit the farm, and that he did not want his mother in the house any more after he had killed his father.
He was convicted of double murder and desecration of a body at Kassel District Court earlier this year, and has now lost his appeal against the life sentence.