title: Effects of sodium sulfite on recovery and composition of detergent fiber and lignin.
abstract: Use of sodium sulfite to reduce nitrogenous contamination in fiber analysis was evaluated. The effects of sodium sulfite on analytical accuracy and precision were examined for amylase-treated neutral detergent fiber (aNDF), sequentially determined acid detergent fiber (sADF), and acid detergent lignin (sADL) in animal feeds. In one experiment, 0.5 g sodium sulfite was added per sample during neutral detergent (ND) extraction. The treatment consistently reduced aNDF, sADF, and sADL values of 180 alfalfa samples and improved precision (decreased within-sample variance of replicated analyses). The greatest effect was on precision of sADL analysis, with within-sample variance reduced by more than 50%. In a second experiment, 24 animal feeds were analyzed for a aNDF, sADF, and sADL with and without addition of 0.5 g sodium sulfite per sample during ND extraction. Nitrogen contents of the recovered fiber fractions were determined. Sodium sulfite reduced fiber and lignin values and decreased nitrogen concentration in residues. Within-sample variance was lower in all analyses. In a third experiment, 23 animal feeds were analyzed for aNDF with sodium sulfite at 0, 0.25, 0.5, and 1.0 g per sample. Average aNDF of feeds was reduced by each additional increment of sodium sulfite; however, 1.0 g sodium sulfite resulted in only a slight reduction in aNDF compared with 0.5 g. Therefore, 0.5 g sodium sulfite per sample should be added to samples prior to aNDF analysis.
authors.affiliation: U.S. Department of Agriculture Research Service, U.S. Dairy Forage Research Center, Madison, WI 53706, USA.
authors.forename: R W
authors.initials: RW
authors.lastname: Hintz
authors.forename: D R
authors.initials: DR
authors.lastname: Mertens
authors.forename: K A
authors.initials: KA
authors.lastname: Albrecht
mesh_terms: D000681:Amylases / Q000494:pharmacology; D000821:Animal Feed / Q000032:analysis*; D003902:Detergents / Q000032:analysis*; D004043:Dietary Fiber / Q000032:analysis*; D005504:Food Analysis / Q000706:statistics & numerical data*; D006863:Hydrogen-Ion Concentration; D008031:Lignin / Q000032:analysis*; D000455:Medicago sativa / Q000737:chemistry*; D009584:Nitrogen / Q000032:analysis; D012680:Sensitivity and Specificity; D013447:Sulfites / Q000494:pharmacology*
chemical_list: D003902:Detergents; D004043:Dietary Fiber; D013447:Sulfites; D008031:Lignin; D000681:Amylases; D009584:Nitrogen; C025026:sodium sulfite