Factors affecting ANKOM™ fiber analysis of forage and browse varying in condensed tannin concentration.
BACKGROUND
Browse species containing condensed tannins (CTs) are an important source of nutrition for grazing/browsing livestock and wildlife in many parts of the world, but information on fiber concentration and CT-fiber interactions for these plants is lacking.


RESULTS
Ten forage or browse species with a range of CT concentrations were oven dried and freeze dried and then analyzed for ash-corrected neutral detergent fiber (NDFom) and corrected acid detergent fiber (ADFom) using separate samples (ADFSEP) and sequential NDF-ADF analysis (ADFSEQ) with the ANKOM™ fiber analysis system. The ADFSEP and ADFSEQ residues were then analyzed for nitrogen (N) concentration. Oven drying increased (P < 0.05) fiber concentrations with some species, but not with others. For high-CT forage and browse species, ADFSEP concentrations were greater (P < 0.05) than NDFom values and approximately double the ADFSEQ values. Nitrogen concentration was greater (P < 0.05) in ADFSEP than ADFSEQ residues, likely due to precipitation with CTs.


CONCLUSIONS
Sequential NDF-ADF analysis gave more realistic values and appeared to remove most of the fiber residue contaminants in CT forage samples. Freeze drying samples with sequential NDF-ADF analysis is recommended in the ANKOM™ fiber analysis system with CT-containing forage and browse species.
Terrill
Thomas H
TH
Agricultural Research Station, Fort Valley State University, Fort Valley, GA 31030, USA.
Wolfe
Richard M
RM
Muir
James P
JP
D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D000835:Animals, Wild; D003890:Desiccation / Q000379:methods*; D004043:Dietary Fiber / Q000032:analysis*; D007887:Fabaceae / Q000737:chemistry; D005504:Food Analysis / Q000379:methods*; D058751:Livestock; D009584:Nitrogen / Q000032:analysis*; D018515:Plant Leaves / Q000737:chemistry; D006109:Poaceae / Q000737:chemistry; D044945:Proanthocyanidins; D029963:Quercus / Q000737:chemistry
D004043:Dietary Fiber; D044945:Proanthocyanidins; D009584:Nitrogen