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ARS Home » Midwest Area » St. Paul, Minnesota » Plant Science Research » Research » Publications at this Location » Publication #78494
Title: COMPARISON OF KLASON LIGNIN AND ADL BY CALORIMETRY

Author
item Jung, Hans Joachim
item Varel, Vincent

Submitted to: American Dairy Science Association Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 6/23/1997
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: The accuracy of lignin concentration estimates of forages based on the acid detergent lignin (ADL) and Klason lignin procedures were compared using calorimetry. Ten diverse forage samples were dried and ground to pass a 1mm screen in a cyclone mill. Forages were analyzed for protein (N x 6.25), carbohydrates (neutral sugars and uronic acids), lipids (ether extract), ash, Klason lignin, and ADL. Forages were also analyzed for gros energy (GE) content by bomb calorimetry. Measured GE was compared to calculated GE based on the following formula using published GE values for components and measured component concentrations: GE = (protein x 5700 kcal/kg) + (carbohydrate x 4000 kcal/kg) + (lipid x 9500 kcal/kg) + (lignin x 8000 kcal/kg). Calculated GE accounted for significantly more of measured forage GE using the Klason lignin concentration value (87.6 to 97.1%) than observed using ADL concentration (66.1 to 81.3%). Because Klason lignin concentrations in forages are two to five times greater than ADL concentrations, Klason lignin has often been considered to overestimate lignin concentration. However, if this were true, calculated GE based on Klason lignin should exceed measured GE. This was not observed and use of Klason lignin gave a better correspondence between calculated and measured GE values than did ADL. Therefore, we conclude that Klason lignin concentration is a more accurate estimate of lignin concentration in forages than ADL. However, as shown previously, both lignin procedures are similarly correlated with forage digestibility.