There is strict regulation around the antibiotic types that are permitted for use in food-producing animals. These are only authorised under veterinary prescription.
Milk contains antibiotics.
If antibiotics need to be used, specific withdrawal periods are designated to ensure that milk from an antibiotic treated cow does not enter the food chain. The Department of Agriculture, Food and the Marine (DAFM) conducts routine farm inspections and has a veterinary inspectorate that is responsible for the implementation of a national milk residue monitoring plan, as required under EU directive 96/23/EC.