Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on safety and efficacy of methionine-zinc, technically pure (Met-Zinc) as compound of trace element for all species, and as amino acid for ruminants.
Based on published literature, the FEEDAP Panel concludes that additive Met-Zinc is safe for all animal species/categories considering that its use in feed is first limited by the regulatory maximum content of zinc. However, its contribution to dietary methionine needs consideration when formulating diets.
Methionine from Met-Zinc would be incorporated into animal tissues and products, showing a constant amino acid pattern. Zinc from this feed additive would not lead to higher zinc deposition in tissues/products, and hence consumer exposure, than zinc from other authorised zinc sources. The FEEDAP Panel concludes that the use of Met-Zinc in animal nutrition is safe for consumers when used up to the maximum authorised level of zinc.
In the absence of data, the compound should be considered as a potential irritant to skin and eye and a skin sensitiser. Zinc compounds are hazardous by inhalation; Met-Zinc shows a high dusting potential, thus exposure by inhalation represents a hazard to persons handling the additive.
The use of Met-Zinc in feed as a source of zinc does not pose an additional risk to the environment, compared with other sources of zinc for which it will substitute, as long as the maximum authorised content in feedingstuffs is not exceeded. Methionine from the additive does not represent a risk to the environment.
In studies comparing bioavailability of zinc from Met-Zinc and from zinc oxide, a higher digestibility and body retention of zinc from Met-Zinc in piglets and equivalent responses in plasma and tissue level of zinc in chickens for fattening fed diets were shown; consequently the additive Met-Zinc is considered an efficacious source of zinc for all animal species/categories. The weak evidence put forward for Met-Zinc is insufficient to conclude on its efficacy in ruminants; however, considering also the evidence reviewed in a recent EFSA opinion on the efficacy of DL-Met in ruminants, the FEEDAP Panel concludes that Met-Zinc has some potential to be an effective source of methionine for ruminants.
The FEEDAP Panel made some recommendations with regards to the specification of the additive.