Is there a difference in the way Canada and the U.S. measure and report protein content?
Yes there are some differences, as well as many similarities.
An important difference is in the reporting of test results for wheat. In Canada, protein for wheat is reported on a 13.5% moisture basis and in the U.S. protein for wheat is on a 12% moisture basis. This difference in moisture will result in U.S. protein being reported as approximately 0.2% higher than the equivalent Canadian value. In other words, in Canada a 13.5% protein on 13.5% moisture basis is equivalent to a 13.7% protein on a 12% moisture basis in the U.S.
In terms of barley, the moisture basis for protein in the U.S. and Canada is reported on a dry matter basis, as such there is no adjustment required.
Both the Canadian Grain Commission (CGC) and U.S. Federal Grain Inspection Service (FGIS will report protein on an alternate moisture basis upon request using simple mathematical calculations to convert results.
The CGC in Canada and FGIS in the U.S. use the same reference method for analyzing the protein content of grains and oilseeds which is combustion nitrogen analysis (CNA). The CNA laboratory supports the NIRT instruments that are used for official testing in Canada and the U.S. The CNA reference method incinerates samples and captures and measures the nitrogen content. This is then converted to protein content. FGIS and CGC use CNA method AOAC 992.23, or the equivalent method AACC 46-30