Withdrawal period for Elancoban® for chickens for fattening, chickens reared for laying and turkeys for fattening

Following a request from the European Commission, the European Food Safety Authority was asked to deliver a scientific opinion on the proposal for reducing the withdrawal period from three days to one day for the product Elancoban® for chickens for fattening, chickens reared for laying and turkeys for fattening. The marker residue data submitted was based on an analytical method with a LOQ of 0.025 mg monensin kg-1 wet tissue, which is about three times higher than the existing MRL for liver, kidney and muscle. The Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) does not consider the data submitted provides additional substantial information. A number of monensin metabolites (M1, M2, M5, M6) were isolated and tested for their biological activities. The antimicrobial activity of the monensin metabolite M1 was nearly equal to that of monensin, whereas that of M2 and M6 was lower. However, the antimicrobial data was not considered further because the ADI is based on pharmacological data. All monensin metabolites tested appeared to show lower ionophoric activity than the parent compound. These findings confirm the results of earlier studies. Comparable results on reduced ionophoric activity of metabolites from a related polyether antibiotic support the above findings on monensin. Non-extractable residues in chicken liver and kidney after a one-day withdrawal period amount to more than 50 % of the total residues. About 90 % of total radioactivity was associated with the abdominal fat in chicken for fattening. In milk, about 25 % of the total residues are attributed to fatty acids. The FEEDAP Panel concludes that a considerable part of the nonextractable residues is not drug-related. The FEEDAP Panel, following a weight of evidence approach, concludes that monensinderived residues of toxicological relevance probably represent, as a conservative estimate, not more than 50 % of the total residues. After applying a 50 % reduction of the toxicological relevance of total residues, the human exposure would amount to 0.056 mg day-1 (31 % of the ADI). Based on the MRL values retained, the consumption of chicken edible tissues would contribute to 49 % of the ADI. Recent marker residue data obtained after one-day withdrawal in chicken for fattening were below the MRLs. Therefore, a one-day withdrawal time for Elancoban® for chickens for fattening and reared for laying, and turkeys for fattening could be set. This conclusion is in agreement with the proposed reduction of the toxicological relevance of the total residues in poultry, which is based on a one-day withdrawal period.