Farmer Claes Roempke, 47, of Stjarnhov, said he was baffled by the disappearance of the cows, which he valued at about $107,600, Swedish news agency TT/The Local.se reported Friday.
"When I opened the gate, I saw the animals were gone," Roempke said. "I have no idea where they've been taken. I hope they are alive and are OK."
Police said they are investigating the incident.
"We have the ID number of all the cows and will match them with the Jordbruksverket (the Swedish Board of Agriculture) register," police spokesman Thomas Tellebro said. "But it is hard to get hold of people during the Christmas holiday period."
He said it is unlikely the thieves took the cows to a slaughterhouse.
"It's not easy to get rid of cows. If someone comes with 69 cows to a typical slaughterhouse, the cows must be registered and that's how the slaughterhouse sees where the cows came from," Tellebro said.