US cattle, pig, chicken and turkey farms are routinely using four antibiotics that have been banned in the UK and two others that have never been permitted, according to a report by the Sustainable Food Trust.
They also use four other antibiotics in ways that would be illegal in the UK, as well as the beta-agonist, ractopamine not permitted here on food safety grounds.
The drugs are used at low levels in feed for prolonged periods to make animals grow faster and/or suppress diseases of intensification in beef feedlots and other factory farms, it says.
This creates the ideal conditions for the development of antibiotic resistance.
Eight of the antibiotics were once permitted in the UK to make animals grow faster but this practice was completely ended by 2006.
Of the other two, one has never been permitted in the UK for any purpose.
In the US, five of the antibiotics are openly on sale over the counter just to make animals grow faster.
There are urgent antibiotic resistance reasons why the farm use of bacitracin, one of these antibiotics, should be ended as soon as possible and longer-term reasons why the routine farm use of the other five antibiotics should not be permitted, says the report.
Of the remaining former growth-promoting antibiotics no longer licensed in the US specifically for growth promotion, carbadox should be banned immediately due to the potential for carcinogenic residues to be left in pork.
There are also long-term antibiotic resistance concerns about the others.
The report says the issue could impact UK consumers and livestock farmers if a free-trade deal is negotiated with the incoming US administration that fails to insist that only meat produced to the higher welfare, hygiene and drug-use standards that exist in the UK can be imported.
The EU is proposing to go further and ban all preventative use of antibiotics in groups of animals from 2022 and to require producers exporting chicken to the EU to do the same.
Beta-agonist ractopamine, used in the US to increase growth in beef cattle, pigs and turkeys just ahead of slaughter, is banned in the UK, EU, Russia and China on food safety grounds.
There are also significant concerns about its welfare effects on the animals.
In a letter to Secretary of State for the Environment, George Eustice, SFT policy director and author of the report, Richard Young, said: “Given the growing worldwide problem of antimicrobial resistance, it would be completely irresponsible if the Government were to allow the importation of beef, pork or poultry meat produced with the use of antibiotics for growth promotion which have been banned here, or the use of antibiotics that are licensed in the UK but used in the US for disease suppression in ways that would be illegal here.”