Our group has been working with steroid hormones for over 40 years and we aim to extend analytical possibilities for this research field. As information about faecal steroid metabolites was very limited, our special interest has been steroid metabolism and excretion in animals, mainly domestic livestock. Starting with these infusion experiments, we have focused on faecal glucocorticoid metabolites. In sheep, we characterized 14C-cortisol metabolites by LC/MS. This helped to establish an enzyme immunoassay for 11,17-dioxoandrostanes (11-oxoaetiocholanolone EIA) for a determination of faecal cortisol metabolites (Palme and Möstl, 1997). It was the first EIA worldwide to measure cortisol metabolites in faecal samples. In the meantime, we have developed and established a total of more than 15 different EIAs for other groups of faecal cortisol or corticosterone metabolites. The biological relevance of these EIAs for evaluating adrenocortical activity in various species (including birds) has been proven (see review Palme, 2019).