Organic forms of trace elements as feed additives: Assessment of risks and benefits for farm animals and consumers

Abstract

Essential trace elements (TEs) are major nutritional feed additives, required for the health and welfare of farm animals, especially under intensive husbandry conditions. Within the European Food Safety Authority (EFSA), risk assessment of feed additives is carried out by the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP), which is increasingly confronted with additives based on organic forms of TEs. Organic forms are expected to have higher bioavailability, hence, lower levels in feeds may be needed to meet farm animal requirements. On the other hand, higher bioavailability might also lead to enhanced deposition in edible tissues, hence, increased consumer exposure; specific organic forms might also have a different distribution in edible tissues or products. Higher consumer exposure is especially relevant to TEs with recognized health risks at excess levels (e.g., Se); exposure scenarios should take into account background dietary levels and other intake sources (e.g., supplements). Tolerable upper intake levels (ULs) for adults and children are the basis for risk assessment; when no UL is defined (e.g., for Mn), a conservative estimate should assess whether the organic form in feeds might significantly increase the consumer’s intake above the dietary background. In perspective, specific maximum allowable contents might be considered for organic forms of TEs in feeds, when supported by a robust database as well as by targeted analytical methods.