EFFECT OF DRYING METHOD AND CONDENSED TANNIN ON DETERGENT FIBER ANALYSIS OF SERICEA-LESPEDEZA

The effect of forage drying method on interrelationships between conde nsed tannins and fiber as determined by the detergent system of analys is was studied in a randomized block field experiment with three culti vars of sericea lespedeza (Lespedeza cuneata (Dum-Cours) G Don). Harve sted forage was oven-dried and freeze-dried, and neutral detergent fib er (NDF) was determined with and without sodium sulfite added during t he extraction. Acid detergent fiber (ADF), permanganate lignin, cellul ose, and acid detergent insoluble nitrogen CN) were determined by sepa rate and sequential ADF analyses. Without sodium sulfite, oven-drying, compared with freeze-drying, increased NDF, neutral detergent insolub le N, and sequentially-analyzed ADF and lignin, due to precipitation o f condensed tannins and protein in neutral detergent. Acid detergent f iber, lignin, and acid detergent insoluble N were higher in sequential ly-analyzed oven-dried and freeze-dried forages, compared with separat e-sample analyses, with a greater effect in oven-dried samples. Neutra l detergent fiber of both oven-dried and freeze-dried samples containe d tannin-protein complexes (precipitants), with more occurring in oven -dried samples. When sodium sulfite was included in the neutral deterg ent extraction, all drying treatment differences in NDF, neutral deter gent insoluble N, ADF, acid detergent insoluble N, and lignin were rem oved. Sequential NDF-ADF analysis with sodium sulfite is recommended t o minimize influence of condensed tannin on the detergent fiber system for sericea lespedeza.