Crude protein Calculator
Crude protein is an estimate for total protein. A crude protein contains nitrogen from not only protein but non-protein sources as well. Crude protein is used for energy and helps build tissue. Crude Protein (CP) is based on a laboratory nitrogen analysis, from which the total protein content in a feedstuff can be calculated by multiplying the nitrogen figure by 100/16 or 6.25. This is from the assumption that nitrogen is derived from protein containing 16 % nitrogen (AOAC, 1984). However, some portion of the N in most feeds is found as non-protein nitrogen (NPN) and, therefore, the value calculated by multiplying N x 6.25 is referred to as crude rather than true protein. Protein is made up of amino acids.
Micro Kjeldhal Distillation Method
Percentage of crude protein = (blank-titre value) * 1.401 * 6.25 * 20 * Normality of NaOH / Sample Weight)