Nutritive Value of Cistus ladanifer L. for Ruminants: Seasonal Variation of Chemical Composition, Digestibility, and Antioxidant Activity of Its Morphological Fractions

Cistus ladanifer has been used in ruminants feeding systems, but there is no information about the seasonal variation in chemical composition and nutritional value of each morphological fraction during its growth cycle. This study characterized the morphological fractions of C. ladanifer (leaves, stems, flower buds, flowers, and seed heads) throughout the year in chemical composition, in vitro digestibility, and antioxidant activity. The leaves were the morphological fraction more variable throughout the seasons, being characterized by low protein level (48.5-114 g/kg dry matter (DM)), moderate cell-wall content (240-267 g NDF/kg DM), high levels of condensed tannins (CT) (131-246 g/kg DM), and low in vitro organic matter digestibility (IVOMD) (29.3-34.3%). The distinctive chemical composition among various morphological fractions allowed the identification of four distinct groups, the first composed by stems, the second by the leaves, the third by the seed heads, and the last one by the flower buds and flowers. All the morphological fractions are sources of bioactive compounds namely phenolic compounds. Leaves are the fraction with higher nutritive value, especially when collected during winter and spring.