Visual appraisal takes into account color, leaf content, stem texture, maturity, contamination from weeds, mold and soil, and others, which all have a great deal to do with the quality and palatability of forages. Dry matter content is important because all animal requirements are made on a dry matter basis. It is impossible to compare different forages without using percent dry matter as the baseline.
Minerals are important in the quality test.
The minerals typically determined are calcium and phosphorus, though many other minerals are important too. Crude protein value includes both true protein and non-protein nitrogen compounds. This is the insoluble portion of the forage and contains the cellulose, hemicellulose, lignin, and silica, which is commonly referred to as the cell wall fraction. NDF is has been shown to be negatively correlated with dry matter intake, or in other words, as the NDF in forages increases, the animals will be able to consume less forage. NDF increases with advancing maturity of forages.