The stress suffered by animals as they are transported across Europe will be lessened as new laws come into force.
European law says calves must have bedding until two weeks old
Lorries used to carry cattle for eight hours or more must be licensed to ensure they are equipped with drinking systems and temperature monitors.
New lorries must also have satellite navigation, to make it easier to check compliance with travel and rest times.
The rules comes into force days after another EU law banned veal crates, in which calves have no room to turn.
Animal welfare group Compassion in World Farming (CIWF) said the new regulations on animal transport were an improvement, but regretted that nothing had been done to restrict the length of journeys.
It welcomed the fact that the lorries would now have to be licensed, and that from January next year, drivers would have to have a certificate of competence to prove that they had been trained to care for the animals.
Transport firms carrying live animals already need to be licensed.
The new regulation also bans the transport of female animals less than one week after they have given birth, and new-born animals. These are defined as:
- Pigs less than three weeks old
- Lambs less than one week old
- Calves less than 10 days old
All lorries, including old lorries already in use for live animal transports, will have to be fitted with satellite navigation by 2009.
Live transports of calves from the UK to Europe resumed in May last year, after a 10-year ban imposed because of the UK outbreak of BSE, or mad cow disease.
Between May and October, 44,000 animals had been transported to continental Europe, according to CIWF. Some are taken to distant destinations - such as southern Italy - on journeys lasting up to 60 hours.
Peter Stevenson of CIWF said that despite the ban on veal crates, calves born in the UK would still be fattened in conditions that were illegal in this country.
Although calves now had to be kept in groups, the British requirement for "appropriate bedding" did not exist in most countries to which the calves were exported, so they were usually kept in buildings with bare concrete or slatted floors.
The law banning veal crates only insists on bedding for calves up to two weeks old.
"We are delighted that veal crates have been banned, but it doesn't mean things are perfect for calves - far from it," he said.
He added that CIWF would continue to campaign for a ban on live transports lasting more than eight hours, and for a complete ban on live transports from the UK.
European Health Commissioner Markos Kyprianou said the European Commission would bring forward new proposals on travelling times, and on the densities at which animals could be kept by the end of 2009.