To face current challenges, ruminant feeding systems have to adapt the use of common resources or develop the use of alternative ones. This study explored the potential of alternative plant resources that could be used on farms to provide nutrients with health-promoting abilities for ruminants, i.e. tree leaves (Lutèce elm, common ash, goat willow, white mulberry, Italian alder, black locust), duckweeds, reeds and grass from orchards. Samples were collected in summer 2022 and assayed for condensed tannin, tocopherol, carotenoid, total polyphenol contents and antioxidant activity (DPPH assay). Tree leaves except white mulberry had the highest total polyphenols (67.1 vs 10.9 mg eq gallic acid g-1 DM for other resources) and DPPH values (118 vs 25 mg eq trolox g-1 DM for others). Black locust was the richest in tannins and carotenoids whereas goat willow was the richest in tocopherols. DPPH values were positively correlated with total polyphenols (r = 0.93) and tocopherols (r = 0.66), in agreement with their significant antioxidant activity. To conclude, several tree leaves seem to be good sources of metabolites with health-promoting abilities for ruminants