A Waimate dairying farming company has been fined a record $6,000 for sending bobby calves containing a prohibited drug to the works.
The Food Safety Authority brought the case against Cantley Developments Limited after a calf it sent for processing in September last year showed residues of sulphonamides.
The class of drugs is commonly used for treating bacterial infections in cattle.
Food Safety Authority assistant director Justin Rowlands says the level of fine sets a new precedent.
He warned that farmers need to be very aware of dosage rates and withholding periods for the veterinary compounds they use.
The residue level did not pose a risk to human health.