A fifth farmer reported a bull had been shot and killed on Thursday night at a Rongahere Rd property in Beaumont.
Mr Adam said the carcasses were left to rot in the paddocks where they were shot.
"No meat was gathered from them.
"You could almost understand if they had taken them for meat if they were hungry, but they've just left them."
He believed the culprits might be "boys in a four-wheel-drive".
"There's a lot of people go shooting around those back roads at night.
"They probably didn't see any possums or rabbits to shoot, so they decided to have a go at my livestock.
"These cows, they've been sitting down sleeping, so they've been easy targets."
Mr Adam was angry at the actions of the shooter or shooters, saying they were selfish.
"This is my livelihood they're playing with and now I've got two calves running around without their mums," he said.
"Just pull your head in. If you're hungry, take a bit of meat off them. Don't leave them to waste."
He said their actions were also careless.
"It's a public road and I might be out there in the paddock and a stray bullet . . . it's dangerous."
Senior Sergeant Jared Kirk, of Dunedin, said police were investigating the shootings.
"Police are taking these incidents, which we believe are linked, very seriously and are making a number of inquiries to locate who is responsible.
"This is distressing for the people involved and members of the public in these communities, so we want to assure people these animal deaths are being investigated thoroughly."
Snr Sgt Kirk said it was possible there were other incidents of stock being killed over the past few days which had not yet been reported to police.
"We are keen to hear from anyone else in Otago who may have been affected, and anyone who may have information which could assist us with our investigation.
"Someone out there will know who is responsible and we encourage them to come forward."
• Dunedin police (03) 471-4800, Crimestoppers 0800-555-111.