A summary of the advantages and disadvantages of various labelling materials is given in Table 1. For example, don't use twine or tape because they can cause leg or tall lesions if attached so tight that circulation is obstructed. Another method is to keep antibiotic treated cows in a separate pen and milk them last. Regardless of the marking system used, make sure all milkers know the meaning of the marks or labels being used. Furthermore, labelling systems, although essential for identifying treated cows, are not a substitute for permanent written records.
Many dairymen successfully use barn blackboards to temporarily record antibiotic treatments.
If there is ever any uncertainty as to how long a cow's milk should be withheld, test the milk for antibiotics before it is put into the bulk tank. Dairy fieldmen can run tests for antibiotics in milk upon request. If properly run, this test can tell when the milk is free of antibiotics. Direct questions concerning this test or where to get labelling devices to your market fieldman or extension dairyman. Visibility, advantages, and disadvantages of products used to identity antibiotic treated dairy cattle.