Opinion of the Scientific Panel on Additives and Products or Substances used in Animal Feed on the safety and efficacy of the coccidiostat Elancoban® (monensin sodium) as a feed additive for calves for rearing and cattle for fattening in accordance with Regulation (EC) No 1831/2003

Elancoban® (Elancoban G200, Elancoban 200, Elancoban G100, Elancoban 100 formulations) is a feed additive intended for the control of coccidiosis, authorized for use for a 10 years period for chickens for fattening, fattening turkeys and chickens reared for laying. The applicant is now seeking for an extension of use of Elancoban® for calves for rearing and for cattle for fattening at dose levels of 30 to 45 mg Mo-Na kg-1 complete feed. Elancoban® contains monensin sodium (Mo-Na), a polyether ionophore produced by Streptomyces cinnamonensis that exhibits both antibacterial and anticoccidial activities, as the active ingredient. The European Food Safety Authority, in accordance with Regulation (EC) No. 1831/2003, was asked by the European Commission to assess the efficacy and the safety of this product for the target animals, the users, consumers and the environment. Studies on calves with artificial and natural infection as well as a study after natural infection on cattle for fattening demonstrate that 0.9 mg Mo-Na kg-1 bw is effective in controlling coccidiosis. Data after artificial infection with Eimeria spp. indicate a potential effective dose range of 0.6-1.2 mg Mo-Na kg-1 bw. The absence of complete feed intake data in eight out of the nine trials does not allow an exact conversion of mg kg-1 bw data into mg kg-1 complete feedingstuff but only an approximation. Taking into account the reservation above, 30-45 mg Mo-Na kg-1 complete feedingstuff can be considered as effective dose range. Short duration of all trials (four weeks) prevents the full assessment of efficacy for continuous use. No specific studies on resistance of Mo-Na against bovine Eimeria spp. have been provided. Since the resistance to anticoccidials (including Mo-Na) is a well known phenomenon in poultry which does not seriously affect their efficacy in the field, a similar situation is expected to occur with bovines. The quality of animal products is not influenced by feeding monensin. Tolerance tests indicated that a dose range of 30 to 45 mg kg-1 complete feed can be considered safe for calves for rearing and cattle for fattening, with a margin of safety of approximately 2.5. The margin of safety for accidental overdosing (no longer than 10 days) is considerably higher. Incompatibilities or interactions with feedingstuffs, carriers or other approved additives are not expected considering the known history of Mo-Na. However, the simultaneous use of Elancoban® and certain antibiotic drugs (i.e. tiamulin) is contra-indicated. Mo-Na at the dose levels proposed for use in bovines may be toxic to equines. There is no evidence that the use of Elancoban® in cattle contributes to the development of cross-resistance by bacteria to antibacterials used in human or veterinary medicine. As in poultry and the rat, Mo-Na is significantly absorbed in bovines, then extensively metabolized to give a similar qualitative pattern of metabolites. It is mainly excreted (unchanged and as metabolites) in the faeces. Unchanged monensin represents 50% of the whole Mo-Na related molecules in faeces. Liver is the target tissue. Unchanged monensin represents less than 10% of the whole residues in liver and disappears very rapidly from all tissues. As already assessed in the previous opinion on Elancoban® (EFSA, 2004), Mo-Na from Elancoban® shows no evidence of genotoxicity, carcinogenicity, embryotoxicity, fetotoxicity or teratogenicity. An ADI of 0.003 mg kg-1 bw d-1 has been proposed, applying a safety factor of 100. Mo-Na total residues in tissues have been measured in animals at steady state administered [14C] Mo-Na at a dose of 33 mg kg-1 feed for cattle for fattening and 1.8 mg kg-1 bw for dairy cows. In both cases, Mo-Na is not measurable in the tissues examined (below LOQ, 0.025 mg kg-1) after 12-hour (cattle for fattening) and six-hour (dairy cows) withdrawal. The total exposure of the consumer, calculated on the basis of the highest individual residue levels in the dairy cow study, was 0.167 mg day-1 representing 93% of the ADI. The FEEDAP Panel considered that the dairy cow study offers the highest safety margin. Since the consumer exposure will not exceed the ADI under these worst case conditions, the FEEDAP Panel does not see the necessity for establishing MRLs and consequently for setting a withdrawal period. The extension of use of Elancoban® to cattle does not modify the former opinion of the FEEDAP Panel that monensin is safe for users. The available information suggests that the use of Elancoban® for calves for rearing and cattle for fattening at the maximum recommended dose and under conditions typically for the use of a feed additive (continuous use) will pose a risk for soil organisms. Insufficient data was provided to allow the FEEDAP panel to assess the risk for the aquatic environment (groundwater and surface water).