Fiber and Condensed Tannin Fractions of Leaves and Litter of Nine Texas Trees and Vines.

Tree and vine leaf litter (LL) is used as an opportunistic goat feed in the cool season of Texas; however, nutritional composition and effect of drying on this feed resource is not well known. Previous research on herbaceous species indicates that concentrations of condensed tannins (CT), neutral detergent fiber (NDF), acid detergent fiber (ADF) and acid detergent lignin (ADL) change with drying methods due to the formation of complexes between tannins and cell wall compounds.  The objective of this study was compare the effect of traditional drying methods with the natural drying of LL on CT, NDF, ADF and ADL concentrations in selected Texas trees and shrubs. Species evaluated were: Smilax rotundifolia (SR), Smilax bona-nox (SB), Celtis occidentalis (CO), Quercus stellata (QS), Ulmus crassifolia (UC), Bumelia lanuginosa (BL), Quercus virginiana (QV), Carya Illinoensis (CI), Gleditsia triacanthos (GT). Leaves harvested before autumn shedding were oven dried (OD) or freeze dried (FD). Nets spread on the soil surface were used to collect LL as these fell in late autumn. Fiber fraction and CT (extractable, bound protein, bound fiber and total) were determined. Drying method changed total concentration of CT only in CO, UC and CI (P<0.05). Concentration of fiber bound CT was higher (P<0.05) in OD than FD and LL in the species studied, except in BL, CI and QV. NDF concentration was affected by drying method in SR, CI and GT, where higher values were found in LL. ADF and ADL concentrations were higher in the  LL (P<0.05) of QS, UC, CI, GT. In conclusion, the effect of drying method on the variables evaluated did not show a uniform pattern in the species studied and more studies are necessary to better understand the interaction between drying, CT, and cell wall components.