The FDA’s Center for Veterinary Medicine (CVM) has become aware that the term, “non-lactating dairy cattle,” may be confusing and that users could mistakenly interpret it to mean that drugs approved for use in non-lactating dairy cattle are safe when used in dry dairy cows, i.e., in cows between two lactations. The term “non-lactating dairy cattle” includes replacement dairy heifers, replacement dairy bulls, and dairy calves, according to current animal industry standards and a long standing FDA practice. These classes of dairy cattle have not yet, or would never produce, milk for human consumption. The term non-lactating dairy cattle does not include dry dairy cows. Dry dairy cows have previously produced milk for human consumption and will again in the future after completion of the “dry period” between lactations. These standards are reflected in CVM's Guidance for Industry (GFI) #191 (Appendix III, Species and Classes of Major Food Animals).
This is an important human food safety issue because of the potential for residues of drugs labeled for use in non-lactating dairy cattle to be present in milk of the treated cows, as well as in the tissue of the calves born to the treated cows. In order for these drugs to be approved for use in dry dairy cows, residue depletion studies would be necessary to determine whether there are residues in calves born to the treated dry dairy cows and in the milk produced by the treated cows in their subsequent lactation.
FDA is working with sponsors of products approved for use in non-lactating dairy cattle to revise labeling to clarify that dry dairy cows are not non-lactating dairy cattle and therefore should not be treated with drugs labeled for use in non-lactating dairy cattle.