Scientific Opinion on the safety and efficacy of DL-methionyl-DL-methionine for all aquatic animal species

DL-Methionyl-DL-methionine is intended to replace supplemental methionine in feed for aquatic animal species. This dipeptide differs from free DL-methionine, particularly in its solubility in water. In the organism, DL-methionyl-DL-methionine will be cleaved to produce methionine. Since supplementing appropriate quantities of methionine to meet requirements is safe for the target species, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) extends this conclusion to the safety of DL-methionyl-DL-methionine for fish and crustaceans. The amino acid L-methionine originating from the metabolism of DL-methionyl-DL-methionine in the body is incorporated into the tissue proteins of aquatic animal species, without affecting their amino acid composition. There is no concern for the safety of consumers from the use of the additive under application in aquatic species nutrition. The product DL-methionyl-DL-methionine is not regarded as an irritant to the eyes and the results of an in vitro study indicated that it is unlikely to be an irritant to the skin. It is also considered likely not to be a sensitiser by the dermal route. Since there is no evidence of acute toxicity by the inhalation route it is not regarded as hazardous for the user. The use of DL-methionyl-DL-methionine as an additive to feed for aquatic animal species does not represent a risk to the environment. Based on in vitro and in vivo studies with rainbow trout, carp, tilapia and shrimp, the FEEDAP Panel concludes that the product, DL-methionyl-DL-methionine, is an efficacious source of the essential amino acid L-methionine for fish and crustaceans.