Feed additives, including feed flavorings, require a thorough
evaluation of consumer safety (Fig. 1). As presented by the European
Food Safety Authority (EFSA, 2012a), such an evaluation can
be seen as a four step process from hazard characterization in
laboratory animals or available literature through to determination
of additive residues in the consumable target species. Step 1 is a
hazard characterization usually done in rats, which will also
include the kinetic and metabolic profiling of the additive. Step 2 is
the comparison of these rat data with the kinetics and metabolism
of the feed additive in the target livestock species to determine the
identity and amount of the major metabolites. In case the target
animal would form species-specific metabolites that were not
present in the laboratory rat, gathering additional toxicological
information about this metabolite would be warranted. Step 3
consists of determination of relevant residue levels in the edible