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Determination of %100 Dry Matter in Feed and Forages

  1. For sample to be determined on an dry basis i.e., non- 'A' sample weigh dried paper bag and record weight to 2 decimal places (keep extra bags in oven set at 60oC). For sample to be determined on an as-sampled basis, i.e., an 'A' sample, go to step 7.
  2. Place a representative portion of the sample into the paper bag.
  3. Weigh paper bag and sample and record weight to 2 decimal places.
  4. Dry sample at 60oC overnight.
  5. To prepare for the next morning, label 100 mL beaker. Weigh and record weight to 2 decimal places.
  6. After sample has been dried overnight, weigh bag and sample and record weight to 2 decimal places. (NOTE--When samples await grinding, they should be left in the oven with heat to prevent moisture absorption by the dried material.)
  7. Grind sample.
  8. Mix ground sample thoroughly then fill labeled glass vial with ground sample for analysis.
  9. Pour approximately 10 grams ground sample into pre-labeled and pre-weighed 100 mL beaker. Weigh and record weight to 2 decimal places.
  10. Dry beaker plus sample at 105oC for 3 hours.
  11. After sample has been dried at 105oC, place in desiccator, then weigh beaker and sample and record weight to 2 decimal places.

Calculation of non- 'A' samples

  • bag weight = a
  • bag weight plus sample = b
  • bag weight plus sample after drying overnight at 60oC = c
  • beaker weight = x
  • beaker weight plus sample = y
  • beaker weight plus sample after drying overnight at 105oC = z

% DM = (c-a)/(b-a) * (z-x)/(y-x) * 100

Calculation of 'A' samples

% DM = (z-x)/(y-x) * 100

Calculation for % Moisture

% MOISTURE = 100 - DM

Grinding

Large Sample

  1. Using a large Wiley mill, grind the samples to pass a 1 mm sieve.
  2. Grind the entire sample and mix thoroughly before transferring the sample or an aliquot to a labeled glass vial.

Small Sample

  1. Grind in the small Wiley mill to pass a 20-mesh sieve.

Feed Sample to be Determined on an As-Sampled Basis - 'A' Sample

  1. Pour about 50 grams of sample into coffee grinder. Grind for approximately 30 seconds.
  2. Mix sample then transfer to a labeled glass vial.

NOTE -- When samples await grinding, they should be left in the oven with heat to prevent moisture absorption by the dried material.