| Abstrakt: |
Sericea lespedeza [Lespedeza cuneata(Dumont de Courset) G. Don., SL] is a perennial, warm-season forage legume with wide adaptation, freeze tolerance, establishment ease, and persistence under grazing. It has high condensed tannin (CT) concentrations (g kg-1), which could be useful for methane mitigation and rumen bypass protein, as well as insect pest and gastro-intestinal nematode suppression. However, CT concentration is variable. Our objective was to test CT, crude protein (CP), and fiber concentrations at five locations (Georgia, Alabama, North Carolina, Louisiana, and Texas) during a growing season. Established ‘AU Grazer’ SL regrowth and accumulated herbage in separate trials was sampled starting late April 2010 every 35 d for four dates. Regrowth CP concentration ranged (P= 0.05) from 127 g kg-1in North Carolina on date 3 up to 221 g kg-1in Alabama on date 1. Sericea lespedeza regrowth in the warmest latitude (Louisiana) consistently contained among the greatest (P= 0.05) acid detergent fiber. In regrowth herbage, we recorded a wide (P= 0.05) total CT range, from 133.5 mg kg-1in Texas on date 3 to 46.1 mg kg-1in Louisiana on date 1, reflecting variability in fiber-bound, protein-bound, and especially extractible CT. Results from accumulated herbage reflected (P= 0.05) herbage ontogenesis with less CP and greater fiber concentration with maturity but showed the same lack of CT concentration pattern as the regrowth herbage. These results indicate that SL herbage nutritive value and CT concentration is variable, so that any hay or pellets sold commercially for CT content should be assayed by environment and crop maturity. |
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