Marks & Spencer has shared information about the use of antibiotics in its farm supply chain - making it the first supermarket in the UK to do so.
It was followed by Waitrose and Asda - putting pressure on other retail giants to do the same.
M&S published details about the drugs used in its milk, chicken and pork products, with Asda sharing details for chicken, dairy and beef.
Waitrose's data covered beef cattle, lamb, turkeys, ducks, egg production and farmed fish.
According to the M&S, animals in these categories are given a lower dose of antibiotics than the industry average, and a lower dose than the target set by the UK’s Responsible Use of Medicines in Agriculture Alliance [RUMA] for 2020.
Suppliers for the categories supplied by Asda and Waitrose also showed levels below industry averages.
The use of antibiotics in farming is a huge concern - the World Health Organization [WHO] has called on farmers to stop using antibiotics on animals on a number of occasions.
The misuse of these drugs in agriculture is causing huge risks to human health, and contributing to the rise of 'superbugs'.
Antibiotics are routinely used in healthy animals for disease prevention, especially in intensive farming.
While it is forbidden to use the drugs for growth promotion in the EU, some fear it still happens. Additionally, it is reportedly commonplace in the US and Asia.
The issue is so serious, that according to Dame Sally Davies, chief medical officer for England, routine surgeries like hip replacements could become high risk because of infection risk in as little as 10 years.
She described this future as a 'post-antibiotic apocalypse'.
This short film talks about the dangers of antibiotic misuse
According to Steve McLean, Head of Agriculture at M&S: "Our farmers use antibiotics responsibly.
"They never use them routinely, never use antibiotics that are critical to human health, and are committed to reducing use every year.
"However, we do not envisage never using them.
"Animal welfare is at the heart of our business, and using them responsibly includes ensuring animals receive the appropriate treatment, under veterinary supervision, when they need it."
Coilin Nunan, Scientific advisor to the Alliance to Save Our Antibiotics, said: "We very much welcome M&S’s, Asda's and Waitrose’s decisions to publish data on their suppliers’ antibiotic use.
"We want to see all supermarkets increase transparency for consumers by publishing similar data.
"Several other supermarkets have already collected data, but are so far refusing to publish it.’
"The publication of this data should help drive average use across the farming industry down, as it illustrates the extent to which many other producers are still overusing antibiotics, despite recent cuts."