Sheep farmer Mark Candy did not realise at first that he had been targeted by rustlers. His Romney ewes graze among trees and rough ground on a Wiltshire country estate, and it was not obvious at first that some were missing.

“Then I sensed that something wasn’t quite right,” said Candy, whose family have farmed in the area for five generations. “I did a rough count and it became clear many of them had gone.”

It turned out that 72 ewes had been taken in the night. Candy was amazed. “At night sheep are glued to the spot they are in,” he said. “They don’t like to move. To get those sheep out of there at night they must have had exceptionally trained dogs and very good stockmanship.”

Candy’s loss is not an isolated one. Figures released this week by the rural insurer NFU Mutual reveal that farm animals worth £3m were stolen from UK farms in 2019.

Large-scale sheep thefts in particular are on the rise, making rustling the most costly crime for Britain’s farmers after agricultural vehicle and machinery theft, according to the insurer.

Candy’s theft was the third in rapid succession within a few miles. His ewes were taken shortly after Christmas from the Bowood Estate at Derry Hill, near Chippenham. The week before, 61 were stolen from a farm near Melksham, 10 miles away. Forty-five sheep were stolen in November from Lacock, just down the road from Bowood.

The loss is hard to take for Candy. He and his wife, Vicky, have worked hard to earn special “high health” accreditation for their flock. It makes replacing the animals they lost harder as they have to source them from farms with the same accreditation or breed from their own animals. It may take two years for the Candys to get them back to where they were at Christmas. “The sheep that have been taken are very difficult to replace,” he said.

Local farmers have started up a WhatsApp group to try to keep an eye out for each other. Candy said he did not believe the police took the issue seriously enough. “If tens of thousands of pounds was taken from a bank they’d be all over it,” he said.

Hazel Coles could not believe her eyes when more than 50 of her sheep suddenly vanished from the fields of her Exmoor farm.

“I ran round the neighbours to check if they had seen them. Could someone have left a gate open? But, no, they had just gone. The first emotion was disbelief. It’s something we’d heard about in other parts of the country but not around here.”

Facebook Twitter Pinterest Large-scale sheep thefts are on the rise, making rustling the most costly crime for the UK’s farmers after vehicle and machinery theft, according to insurers. Photograph: Gareth Iwan Jones/The Guardian

Forty-two ewes and 10 lambs were taken, worth a total of £6,000. Among those taken were four of the farm’s 30 pure-bred Texels. “They are very much a foundation of the flock. They’re quite difficult to breed and in a few minutes they were gone,” said Coles.

Her family has farmed on Exmoor for more than half a century and have never had animals stolen before. Securing the farm is not easy. “Padlocks and chains are next best to a waste of time. They’re too easy to cut.” Coles has placed bales across some gates in areas of the farm.

“But I do worry,” she said. “I don’t really think the sheep are safe. It would be nice to have more police patrols as more of a deterrent but I know they don’t have the resources. You do your best, you put them where you think they’ll be safest but you can’t completely protect them.”

Rebecca Davidson, a rural affairs specialist at NFU Mutual, said rustling caused suffering to farmers and to the animals.

She said: “Rustling has always been an aspect of farming but 10 years ago we would rarely see claims of more than a dozen sheep taken in one go. We are now regularly getting reports of 50-100 sheep being taken in a single raid and it is devastating for farmers.

“As well as causing untold suffering to sheep, which may be in lamb when they are stolen, rustling is causing high levels of anxiety for farmers who have built up their flocks over many years.

“Rustlers are getting more skilled and organised, quickly loading sheep on to trailers and lorries late at night. We are concerned that gangs are now using working sheepdogs, which have also been stolen, to get the job done.”

An alarming trend is the illegal butchery of animals in the field. Rather than having the bother of moving animals – and hiding them until they or their meat can be sold on – thieves sometimes prefer to kill them where they are, butcher the carcasses and leave the remains.

Farmers and their families are devastated when they go to check their flocks to find the bloodied remains. Davidson added: “We believe that meat from stolen animals is being sold on the black market and undermining welfare standards.”

The farmers are trying to fight back. Where possible, they are grazing animals away from roads. Some are setting up devices such as infra-red beams across gates that send alerts to mobile phones if broken. But it can be costly, time-consuming and not always effective.

The police insist that they do take sheep thefts seriously and understand the wide-reaching impact.

PC Emily Thomas, who is investigating the Wiltshire thefts, said: “While of course there is a financial loss to the farmers, this type of theft can also have an emotional impact as in some of these circumstances it would have taken years of breeding to establish the flock. Not knowing what may have happened to the animals can be extremely upsetting.”