Some persistent misconceptions concerning the crude fibre and the nitrogen-free extract

Authors

• Lauri Paloheimo Department of Animal Husbandry, University of Helsinki

DOI: https://doi.org/10.23986/afsci.71343

Abstract

By the usual Weende method the vegetable membrane substances are divided most arbitrarily into two groups, crude fibre and nitrogen-free extract. The bulk of lignin falls in the latter fraction which also contains the valuable cell enclosure carbohydrates, sugars and starch. Many misconceptions even amone eminent scientists still prevail concerning the crude fibre and the N-free extract. It is too often forgotten that N-free extract also contains lignin, and that in some cases crude fibre is a more valuable food fraction than the N-free extract. However, the per cent figure of crude fibre, especially when calculated of the dry matter, is a useful criterion in estimating the value of foods. N-free extract, on the other hand, is only a misleading concept and should be omitted. It would, be best to leave it out also from the food tables.