Britain's first shipment of live veal calves in 10 years has left for the Continent after the decade-long EU ban on beef exports was finally lifted.
Veal calf exports to Europe have resumed after 10 years
A ship carrying calves headed for Belgium left Dover for the French port of Boulogne in the early hours.
The beef industry says a renewed sales drive to Europe will help reinvigorate trade which was worth £20m a year before the BSE crisis.
But animal welfare groups say live veal exports cause unnecessary suffering.
A group of about 70 campaigners assembled at Dover to monitor Friday morning's shipment.
The campaign to stop the exports is being backed by celebrities including actress Joanna Lumley.
Before the BSE crisis put a stop to live exports, they had been the subject of long-running protests by animal rights campaigners.
Thousands took part in protests against the live export of veal calves over the years resulting in some clashes with police and one protester died.
The campaign resulted in some port authorities trying - unsuccessfully - to ban the export.
Exports are resuming after EU vets agreed to lift the ban earlier this year as a result of plummeting cases of BSE in the UK.
The changes mean live cattle born on or after 1 August 1996 may be exported, along with beef from cattle slaughtered on or after 15 June last year.
Restrictions remain in place for beef containing vertebral material and for beef sold on the bone.
France, which was previously the largest importer of British beef, is expected to allow imports from Saturday after its own legislation has been amended.
The British beef industry expects exports to pick up gradually once contracts with buyers in Europe have been re-established.
National Farmers Union spokesman Anthony Gibson said the resumption of exports marked "the best day for British farming for a good many years.
"It marks the end of 10 years in the wilderness for the British beef industry," he added.
But the English Beef and Lamb Executive (EBLEX) said it would take time to build up overseas trade to pre-1996 levels.
Chairman John Cross said: "The whole of our beef industry can allow itself just one good sigh of relief and then be ready to join EBLEX in a monumental push to put our beef back where it belongs - on the plates of consumers around the world."
France is expected to allow live imports from Britain from Saturday
Compassion in World Farming (CIWF) and the RSPCA have protested against the return to live exports, saying the animals suffer during the long journeys and that calves reared for veal are kept in worse conditions on the continent than in the UK.
Farmers point out that the calves are reared and housed in good conditions in the UK and are sent abroad only for slaughter.
The Department for Environment, Food and Rural Affairs says it would prefer calves to be slaughtered in the UK rather than being exported live but that court judgments have made clear a unilateral ban on calf exports by the UK would be illegal.
It says European rules governing the welfare of livestock being transported are much stricter than they were in 1996, when trade ceased - change brought about largely because of UK influence.
CIWF is concerned about the use of "veal crates" on the continent which do not give the animals room to turn around.
Earlier this week, Rowen West-Henzell, of CIWF, said: "Many people thought that this trade had ended permanently in 1996, when the ban was put in place because of BSE.
"Sadly, it seems that the time has not been used productively by the industry to develop more welfare-friendly alternatives to a resumption of the export trade."
The use of veal crates is already banned in the UK and is set to be stopped across the EU from 2007.
Responding to protests ahead of the renewed live cattle trade, the NFU called on British exporters not to send animals to buyers in Europe where veal crates are still in use.
The export ban on UK cattle, meat and products, was ordered by the European Commission on health grounds in March 1996.