Condensed tannins (CT) are bio-reactive complex plant secondary metabolites. Protein-CT complexes could result in affection of rumen fermentation, allow availability of amino-acids and induce a gastrointestinal nematicidal action in ruminants. In this study 5 tropical plants were evaluated to provide some natural multi-active nutraceutics to animal production. The CT composition of plants was quantified and elucidated using vanillin-H2S04 assay and LC-MS analysis. CT extracts were assayed for bioactivity against the exsheathment of the nematode Haemonchus contortus, and fermentation profiles of plants (CH4 and NH3-N produced, organic matter digestibility (OMD)) were determined in vitro. Thiolysis analysis showed that CT extracts contained from 1.7 to 59 g of CT per 100g. mDP ranged from 3.3 to 15.3, PC/PD ratios from 0 to 10.7, cis/trans flavan-3-ol ratios from 1.7 to 24.7, and galloyl groups from 0 to 37.4 %. CT had a high effect (p<0.001) on nematicidal activity and fermentation profile.The complexity of composition of CT in tropical plants and their multipurpose potential for animal production were highlighted. It seems that CT chemical composition may influence bio-reactivity and neutracutical feed value.