Use of 2-ethoxyethanol and alpha-amylase in the neutral detergent fiber method of feed analysis

Use of 2-ethoxyethanol in the NDF procedure for feed analysis was reevaluated, because justification for its use in the NDF procedure has diminished and 2-ethoxyethanol poses potential health hazards. Initial rationale for addition of 2-ethoxyethanol was to minimize inhibitory effects of decalin on filtration and to facilitate starch solubilization. Decalin is no longer recommended in the procedure; alpha-amylase is commonly used to facilitate starch solubilization. Objectives of this study were to evaluate effects on NDF values of: 1) eliminating 2-ethoxyethanol from the procedure and 2) addition of and timing of addition of alpha-amylase. Deletion of 2-ethoxyethanol resulted in lower NDF values than neutral detergent solution with 2-ethoxyethanol (61.95 and 62.06%, respectively). Neutral detergent fiber values were lower for samples treated with alpha-amylase just prior to filtration (61.86%) than for samples not treated with alpha-amylase (62.13%). Addition of alpha-amylase 30 min after onset of boiling resulted in lower values (62.07%) than with no alpha-amylase addition (62.29%) in solutions containing 2-ethoxyethanol but not in solutions without 2-ethoxyethanol. Observed treatment differences were small, however, and probably not of practical significance. No differences in NDF values were noted due to timing of alpha-amylase addition. Inclusion of samples requiring alpha-amylase to filter increased overall mean CV and resulted in no statistical differences between neutral detergent solutions or alpha-amylase treatments. Suggested modifications to the NDF procedure include elimination of 2-ethoxyethanol and addition of alpha-amylase just prior to filtering.