What is a withdrawal period?
Withdrawal period refers to the minimum period of time from administering the last dose of medication and the use of meat or other animal-derived products for food.
For example, if mastitis is treated with a medicine that requires a withdrawal period of 6 days for milk, the treated cow's milk may be delivered to a dairy on the 7th day after the last dose, at the earliest.
The purpose of the withdrawal periods is to ensure that foods do not contain residues of pharmacologically active substances in excess of the maximum residue limit (MRL).
To determine withdrawal periods, data on the drug metabolism in the animal is studied. The results of residue studies on a veterinary medicinal product are then compared with the MRL. The withdrawal period is set so that it is long enough to ensure that medicinal residues in the animal's tissues are below the maximum limit.