Antibiotic use on US farms is at least nine times higher than use on British farms, raising industry concerns over a possible free trade deal post-Brexit.
New research by campaign pressure group Alliance to Save Our Antibiotics shows that antibiotic use in the US is double that for pigs compared to British farms, three times higher in chickens and five times higher in turkeys.
But the highest dosage occurs on American farms rearing cattle for beef, which is at least nine times as much compared to British beef farms.
The EU currently bans US beef due to the widespread use of growth hormones in its industry.
Suzi Shingler, at the Alliance to Save Our Antibiotics, told The Guardian that US cattle farmers are "massively overusing" antibiotics.
“This finding shows the huge advantages of British beef, which is often from grass-reared animals, whereas US cattle are usually finished in intensive feedlots,” Ms Shingler explained.
“Trade negotiators who may be tempted to lift the ban on US beef should not only be considering the impact of growth hormones, but also of antibiotic resistance due to rampant antibiotic use.”
The high antibiotic use rate in the US and parts of Asia has led the World Health Organisation (WHO) to urge farmers worldwide to stop using antibiotics to promote growth and prevent disease in healthy animals because of the serious risks to human health that result.
The UN agency said the overuse of antibiotics in farming has been highlighted as one of the "biggest threats to human health."
British farmers have raised serious concerns that health and welfare standards could be undermined in the rush to secure trade deals with countries like the United States.
Environment Secretary Michael Gove has insisted that the UK wants to maintain high standards of quality after it leaves the European Union, despite clashing with Trade Secretary Liam Fox over the matter, who said he has "no objection" to British people eating lower-standard US meat, such as chlorinated chicken.
This comes at odds with US commerce secretary Wilbur Ross, who said last year in a speech in London that any post-Brexit deal with Washington would hinge on the UK scrapping rules currently operated by the EU.
But earlier this year, Ted McKinney, the Under Secretary for Trade and Foreign Agricultural Affairs at the United States Department of Agriculture (USDA) told the Oxford Farming Conference that he was “sick and tired” of hearing British concerns about US food standards.
During a press conference following his speech, where he was joined by Mr Gove, they were asked about differences in standards between the two countries.
"We will hold our food safety, environment and welfare standards up against the UK any day of the week and twice on Sunday," said Ted McKinney.
"Let's just get that out of the way. We do hope that your consumers have at least the opportunity - we're not going to force feed anyone - at least have the opportunity to invest in an American turkey or chicken or any other piece of protein that might be of their choosing."