P&O Ferries has announced it will immediately stop shipping live calves from Scotland due to welfare concerns.

The company said it would no longer allow calves to be carried on its services from Cairnryan in south-west Scotland to Larne in Northern Ireland, from where they are shipped via Ireland to Spain and Italy for veal production.

A BBC Scotland investigation broadcast on Monday raised fresh questions about the treatment and handling of the animals. It found that two- to three-week-old calves travelled in trucks for up to six days before arriving on the continent.

Scotland is now the only part of Britain that exports young calves because ferry firms refuse to do so from English or Welsh ports.

About 5,000 calves were sent from Scotland through Cairnryan to Ireland and then onwards last year using P&O services, contradicting the ferry company’s policy that it would not ship animals intended for fattening or slaughter.

P&O said: “We can confirm that P&O Ferries will cease co-operating with the Scottish government to transport across the Irish Sea young calves destined for continental Europe with immediate effect.

“We place the highest priority on animal welfare across all of our routes and were shocked by the scenes in last night’s documentary. We will not hesitate to act decisively and close the account of any customer which breaches our policies in this area.”

Male calves are not needed by dairy farms and while many are shot soon after birth, in England and Wales they are frequently bred into adulthood for beef. The Scottish industry insists that exporting them is more productive than shooting at birth.

UK ministers are currently consulting on whether to introduce a formal ban on their export from England and Wales, but Scottish ministers are resisting similar proposals.

Peter Stevenson, a policy adviser for the charity Compassion in World Farming, said the Scottish government should now formally ban live exports and resist any pressure from farmers to get P&O to reverse its decision.

“The Scottish government and farmers have misleadingly presented this as a ‘shoot them or ship them’ decision,” Stevenson said. “This is not the case. The calves should be reared in the UK as beef.”