Rustlers have stolen 55 Friesian bull calves, worth more than $24,000, from a North Canterbury property.
Swannanoa farmers Chris Payne, 37, and Taylor Newcombe, 25, planned to use the money for their wedding.
"It's pretty heartbreaking to be honest," Mr Payne said.
The couple had reared the calves since they were born and hoped that the $450 each calf was worth would pay for their wedding in January.
Mr Payne said the thieves took only the larger calves from the paddock on Tuesday night.
Police confirmed they were investigating.
There have been several cases of stock rustling this year, including 25 calves from Waimate in January.
Mr Payne went to the paddock when his mother-in-law phoned to say the calves were not in their paddock.
"My first thought was that they'd got down to the river, but the further I drove in the paddock the more I realised what was going on. There was tyre marks everywhere. I could see that the gates had been used as races and I could see where the calves had been mobbed up."
The theft was a big hit, he said. The couple raised 200 calves twice a year, outside of their full-time jobs.
"After all the bills have been paid and we sell the rest of the calves and pay our debts, we'll probably break even, might even suffer a loss, but there's no room left in the budget for luxuries like weddings."
The tagging system would be little help in tracking them down, but the calves had one-of-a-kind genetics, Mr Payne said.
"It's a bit gutting really, I just want to know they're safe, it's hard to sleep at night knowing someone else has got them. You can't help to get slightly attached to them, it's quite personal to us - they're our cows and we're proud of them."
"The fella we purchased the calves off has a pretty unique herd and everything is DNA profiled, so any suspicious calf can be DNA tested ... they'd [the thief] have a hard time explaining where they got that calf from."
Senior Sergeant Anna Lloyd said police had received a couple of helpful calls, but there were no solid leads at this stage.
Ms Lloyd said neighbours should keep an eye out for dodgy behaviour and report anything out of place.
Mr Payne hoped getting the word out would help find the calves.