A nine-year ban on the sale of beef for human consumption from cattle aged over 30 months has been lifted.
Cattle born before 1 August 1996 will continue to be excluded
The ban was imposed after the outbreak of BSE or "mad cow disease" which devastated the UK's beef industry.
The Over Thirty Month (OTM) rule has been replaced with a testing regime which means older cattle must test negative to enter the food chain.
The National Farmers' Union (NFU) said the new measures meant consumers could now "buy older beef with confidence".
UK cattle born before 1 August 1996 will continue to be excluded from the food chain.
Lord Bach hailed the lifting of the ban as a "welcome boost" to the British cattle industry.
"The replacement of the OTM rule marks a significant step in the year-on-year decline of the BSE epidemic to record low levels," he said.
The Department for the Environment, Food and Rural Affairs (Defra) said that, ahead of Monday's lifting of the ban, abattoirs have had to meet strict standards, including a two-day assessment and the signing of legally binding contracts on safety.
In December, the Food Standards Agency (FSA) said the OTM rule was no longer proportionate to the risk as the number of cases of the disease had fallen dramatically.
It approved a new BSE testing system in August, following a series of trials.
The Meat and Livestock Commission has said that lifting the ban will lead to a 27% increase in British beef production.
The NFU said the end of the OTM rule paved the way for a complete lifting of EU trade restrictions on UK beef which, it said, should be lifted "as a matter of urgency".
"Politics must not get in the way of a fast and total return of British beef to the single market," vice-president Meurig Raymond said.
In September, it was announced that the EU was set to allow more British beef exports after a favourable report on BSE prevention measures in the UK.
The favourable report and a fall in BSE to below 200 cases per million cattle - achieved earlier this year - were required to take off the restrictions.
After EU chief veterinary officers met, the Health Commissioner Markos Kyprianou said the conditions had been met.
The European Commission is now expected to draw up a proposal to lift the restrictions.
BSE (Bovine Spongiform Encephalopathy) was first defined in the UK in November 1986. Some 83,000 cases have been detected since then.
In 2004 there were 90 clinical cases of BSE - where animals were showing the symptoms of the disease - and 253 cases where laboratory testing found the disease to be present.
The majority of affected cattle were born before August 1996, Defra said.
The human disease Variant Creutzfeldt-Jakob Disease (vCJD), was recognised in 1996 and is thought to result from the consumption of BSE-infected meat.