Do we still need to work with crude protein?

The term crude protein is still often used in diet formulation. But some may question whether this is still up to date. After all, it is all about the amino acids, not crude protein content. The definition of crude protein, which quantifies as the amount of analysed nitrogen multiplied by a factor of 6.25, goes back to the 19th century. In the 1860s, Henneberg and Stohmann attempted to break down feed composition into various groups of substances for analytical purposes. Crude protein was defin