Crude protein will include both true protein and non-protein nitrogen. Cattle can use both types to some varying degree. Crude protein values give no indication if heat damage has occurred, which may alter protein availability. Protein A forage analysis report will not always show this value unless heat damage is suspected and the analysis is requested. This value will give an indication if excessive heating has occurred, reducing protein digestibility.
All forages have some unavailable protein.
In some reports, this value will be the difference between crude protein and unavailable protein. Some laboratories, however, account for the naturally boundprotein found in all forages. This normally bound protein may be up to 12 percent of the crude protein. This value refers to the cell wall portions of the forage that are made up of cellulose and lignin. These values are important because they relate to the ability of an animal to digest the forage.