The lignin and cellulose contents of certain grassland species at different stages of growth

Abstract

1. The lignin and cellulose contents of the dry matter of seven herbage species, including three grasses, two legumes and two herbs, have been determined at different stages of growth. Similar analyses of large samples of crude fibre isolated from early and late cuts of all species were made.2. No considerable differences between the lignin contents of the dry matter of the species were found when comparisons were made at the same stage of growth.3. In a majority of the species examined a marked rise in lignin content was found to occur at the flowering stage.4. The cellulose content of grasses, whether expressed as a percentage of the dry matter or of the carbohydrate fraction, is much higher than that of either legumes or herbs. In consequence, crude fibre contents are greater in the former than in the latter.5. The findings of earlier workers that the composition of the crude fibre varied as between species have been confirmed. It has been shown that, in any one species, the crude fibre make-up is dependent on the stage of growth.6. The recovery of lignin and cellulose in the crude fibre of the different species has been studied. Several possible explanations of the variable recoveries found have been suggested and discussed.7. The case for modification of the conventional method of feeding-stuff analysis, as it applies to the non-fatty and non-nitrogenous organic matter, has been discussed in the light of conclusions reached in the course of this work.