Review: Bioavailability of trace elements in farm animals: definition and practical considerations for improved assessment of efficacy and safety br

Currently, the authorisation procedure of trace elements as feed additives in the European Union accord-ing to Regulation (EC) No. 1831/2003 does not consider the bioavailability of trace element sources. This manuscript provides framework conditions for in vivo experiments that aim to estimate differences in the relative bioavailability between supplements of essential trace elements. Framework conditions encompass necessary technical information on the test substance, the experimental design and diet com-position as well as the suitability of status parameters that allow for relative comparisons of regression variables. This manuscript evolves recommendations for researchers to conduct solid and reliable exper-iments on the matter as well as decision makers to interpret the value of studies submitted with autho-risation applications regarding a certain trace element supplement.(c) 2022 The Authors. Published by Elsevier B.V. on behalf of The Animal Consortium. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

The authorisation procedure of trace elements as feed additives in the European Union does not currently take into account the bioavailability of trace element sources. This manuscript provides a framework for in vivo experiments to estimate differences in the relative bioavailability of essential trace element supplements and offers recommendations for researchers and decision makers.