This report by the European Alliance to Save Our Antibiotics assesses the antibiotics policies of ten leading British supermarkets. It finds that six out of the ten supermarkets ban their suppliers from routinely using antibiotics, with Waitrose having the most comprehensive antibiotic policies.
The report finds that supermarkets have become more transparent on their antibiotic use data since 2017, when none of the ten supermarkets had published relevant data. The data that has now been published by six supermarkets is however, according to the report, not sufficiently detailed in that it does not break down antibiotic use by type of farming system.
Read the full report, Supermarket antibiotics policies assessment 2019, here (PDF link). See also the Foodsource chapter What is the connection between infectious diseases in humans and livestock?