Author
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Mertens, David |
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Submitted to: National Forage Testing Association Workshop Proceedings
Publication Type: Proceedings Publication Acceptance Date: 6/14/1999 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: The ANKOM filter bag system is a semiautomatic method for measuring fiber that allows 24 samples to be analyzed simultaneously. Although they altered pressure in the extraction chamber, small differences in reagent volume (1800 vs. 2100 ml) or starting temperature of the extraction chamber (hot vs. room temperature) had little effect on aNDF analyses using the filter bag system. The lack of significant difference for most treatments and the small magnitude of the difference (about 0.3%-unit of aNDF) when treatments were statistically significant indicates that the filter bag system is relatively rugged when averaged across all materials. Significant differences between procedural treatments for individual samples or materials were often greater than 0.7%-units. Procedural treatments (and the material affected by it) recommended for the filter bag system include: mixing of sodium sulfite and amylase with neutral detergent solution (especially for starchy materials), mixing amylase with wash water (for al materials), soakings four times with water for 5 min. each - first two times with amylase followed by two times without amylase (for all materials, especially legumes), using 2100 mls of hot water (80-90 deg C) and heating the chamber with the lid sealed (for all materials, especially stover, sunflower meal, roasted soybeans, distiller's grains, and meat meal), and soaking twice with 240 mls of acetone for 5 min. with swirling at 0, 2, and 4 min. (for fatty materials that are not pre-extracted). Shaking fat-containing samples during pre-extraction with 240 mls of acetone for 10 min. improved aNDF analysis for only one materials, but cannot be recommended for most samples because fiber was often lost during pre-extraction. |
