Official Grain Grading Guide
Sample feed grain: Determination of dockage
Samples are graded using procedures for sample feed grain when they exceed the broken (BKN) tolerances for mixed grain.
Important: When a sample is to be graded as sample feed grain:
- Return dockage to the cleaned sample.
- Begin cleaning and dockage assessment using the procedures described in this section.
Dockage is assessed and recorded to the nearest 0.1% on all samples.
Normal cleaning procedure
- Using a Boerner-type divider, divide the uncleaned sample to obtain a representative portion.
- Official samples should be at least 1000 grams (g).
- Unofficial samples must be at least 1000 g.
- Sieve the sample over the numberNo. 4.5 round-hole hand sieve, using approximately 250 g at a time.
Composition of dockage
Dockage contains:
- Material that passes through the numberNo. 4.5 round-hole sieve
- Material removed by special cleaning for grade improvement
Rounding rules
Rounding rules are outlined in schedule 3 of the Canada Grain Regulations. When official inspection results are expressed numerically, they should be expressed to the same decimal precision as the applicable tolerance in the primary and export grade determination tables.
Cleaning for grade improvement
If the grade of a sample can be improved by additional cleaning, perform the cleaning and add the additional material to dockage. Cleaning for grade improvement can be done at any time after the cleaning assessment has been completed.
- After the cleaning assessment has been completed, use a numberNo. 6 or a numberNo. 5 buckwheat hand sieve to remove large seeds. Large seeds are removed if their total weight exceeds 3% of the cleaned sample by weight.
- Record the additional cleaning and dockage on inspection records.