Seasonal Quality Assessment of Leaves and Stems of Fodder Ligneous Species

Abstract

The objective of this research was to investigate the effect of seasonality on the chemical composition and concentration of phenolic compounds in some ligneous species. The research was conducted at the Aristotle University’s farm, Thessaloniki, Greece. From five ligneous species (Robinia pseudoacacia var. monophylla, Amorpha fruticosa, Colutea arborescens, Morus alba and Arbutus unedo) samples (leaves and twigs) were collected during two different seasons (spring and autumn). All samples were analyzed for crude protein (CP), Neutral Detergent Fiber (NDF), Acid Detergent Lignin (ADL) and in vitro dry matter (DM) digestibility (IVDMD), as well as for total phenols (TPH), total tannins (TT) and condensed tannins (CT). The CP content was generally lower and higher in leaves and stems of A. unedo and R. pseudoacacia, respectively compared to the other tested species. A. unedo had the highest values in NDF and ADL in leaves and the highest ADL content in stems. M. alba and C. arborescens in leaves and C. arborescens in stems had the lowest values of ADL content. M. alba had the significantly highest value in IVDMD and A. unedo the lowest one in both leaves and stems. Season had no significant effect on TPH, TT, and CT of leaves, while in stems they were significantly higher in autumn. A. unedo had the highest concentration of TPH, TT and R. pseudoacacia of CT in the leaves. TPH, TT, and CT concentration in stems was significantly higher in A. unedo. According to the findings, the impact of maturation on the type and the concentration of phenols and tannins is species-dependent.