The invention relates to the use of an isolated arabinanase enzyme comprising the activities of (1-5)-α-arabinofuranosidic linkage endohydrolysis in (1-5)-α-L-arabinans (EC 3.2.1.99), and hydrolysis of (1-5)-α-arabinofuranosidic linkages at the non-reducing end of α-L-arabinans or α-L-arabinose-oligomers (EC 3.2.1.55), particularly an arabinan-degrading enzyme isolated from Arxula adeninivorans as feed additive in livestock breeding. Furthermore, the invention relates to the application of the arabinanase in the production of fruit juices or biofuels.