Publication Date
1993
Description
The levels of condensed tannins (CT) in 12 herbaceous species growing at 2 sites were determined using a recently modified butanolHCL procedure. The method measured CT extractable in 70:30 acetone: water, and CT bound to protein and fibre, using ground, freeze-dried material. Total plant CT levels ranged from trace to 8% OM, with high concentrations (5-8% DM) being detected in 3 Dorycnium spp. and Lotus pedunculatus. Coronilla varia, Hedysarum coronarium and Lotus corniculatus had CT levels of 2-4% DM which may be appropriate for optimum nutritional value. CT content in ·n. rect11m, D. pe11taphyl/11m and L. pedunculatus was higher at a relatively moist, cool site (mean = 7.1% DM) compared with at a drier, warmer site (mean = 5.8% DM), At the former site, species with total plant CT greater than 2% ·DM often had CT levels in lamina 2-5 times higher than those in stem. In most species with low total plant CT (<0.5% DM), lamina and stem had similar CT concentration,. The proportion of total CT bound to protein ranged from 19% (D. rectum) to 70% (L. teumis). It was recommended that future assays should estimate protein-bound CT in addition to that extractable. Fibrebound CT was 1-20% of total CT in most species and need not be measured in freeze-dried and ground material.
Citation
Douglas, G B.; Donkers, P; Foote, A G.; and Barry, T N., "Determination of Extractable and Bound Condensed Tannins in Forage Species" (2024). IGC Proceedings (1993-2023). 20.
https://uknowledge.uky.edu/igc/1993/session9/20
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Determination of Extractable and Bound Condensed Tannins in Forage Species
The levels of condensed tannins (CT) in 12 herbaceous species growing at 2 sites were determined using a recently modified butanolHCL procedure. The method measured CT extractable in 70:30 acetone: water, and CT bound to protein and fibre, using ground, freeze-dried material. Total plant CT levels ranged from trace to 8% OM, with high concentrations (5-8% DM) being detected in 3 Dorycnium spp. and Lotus pedunculatus. Coronilla varia, Hedysarum coronarium and Lotus corniculatus had CT levels of 2-4% DM which may be appropriate for optimum nutritional value. CT content in ·n. rect11m, D. pe11taphyl/11m and L. pedunculatus was higher at a relatively moist, cool site (mean = 7.1% DM) compared with at a drier, warmer site (mean = 5.8% DM), At the former site, species with total plant CT greater than 2% ·DM often had CT levels in lamina 2-5 times higher than those in stem. In most species with low total plant CT (<0.5% DM), lamina and stem had similar CT concentration,. The proportion of total CT bound to protein ranged from 19% (D. rectum) to 70% (L. teumis). It was recommended that future assays should estimate protein-bound CT in addition to that extractable. Fibrebound CT was 1-20% of total CT in most species and need not be measured in freeze-dried and ground material.
