How this calculation works
Two feeds with equal as-fed mass can contribute very different amounts of dry matter. Water dilutes the wet weight without supplying the same dry nutrients, so a ration comparison needs a consistent basis.
Dry mass = as-fed mass × DM fraction; protein mass = dry mass × dry-basis protein fraction; blended protein = total protein/total DMA worked example
Ten kilograms of ninety-percent-DM hay contributes nine dry kilograms. Twenty kilograms of thirty-percent-DM silage contributes six, for fifteen kilograms total dry matter. At ten and fifteen percent dry-basis protein, the two ingredients contribute 0.9 kg protein each. The blend is twelve percent protein on a dry basis. With entered prices twenty and five per wet kilogram, its cost is three hundred currency units.
Good to know
Entered composition and cost accounting only; no nutrient requirement, digestibility, complete ration or veterinary assessment. All percentages must use the stated bases. A wet-basis protein label cannot be entered as dry-basis protein without conversion.
Reference: Penn State Extension — forage dry matter (opens in a new tab) ↗
What the model answers
Two feeds with equal as-fed mass can contribute very different amounts of dry matter. Water dilutes the wet weight without supplying the same dry nutrients, so a ration comparison needs a consistent basis.
This page totals entered ingredients rather than prescribing a feed allowance. It shows each ingredient’s dry matter, crude protein contribution and cost so the blend can be audited independently of a target nutrient recommendation.
The Pearson square protein blend calculator solves a two-ingredient dry-basis target. This page instead checks the composition of any entered multi-ingredient blend.
Measure and enter consistently
Mass is as-fed kilograms. Dry matter is a percentage of that wet mass, while crude protein is a percentage of the ingredient’s dry matter. Cost is per as-fed kilogram in one currency throughout the table.
Use compatible laboratory analyses and the actual condition of each feed. A stale moisture value can change the dry contribution even if the scales and price are correct. The calculator does not look up feed composition from its name.
Interpret the result
Total crude protein percentage is weighted by dry matter, not by wet ingredient mass or an unweighted average of label percentages. Cost per dry kilogram likewise divides the full entered bill by total dry matter.
A protein total is not a complete ration assessment. Energy, minerals, fiber, digestibility, ingredient limits and species requirements are absent. This arithmetic should not be treated as an animal-health or feeding recommendation.
Work through the numbers
Ten kilograms of ninety-percent-DM hay contributes nine dry kilograms. Twenty kilograms of thirty-percent-DM silage contributes six, for fifteen kilograms total dry matter.
At ten and fifteen percent dry-basis protein, the two ingredients contribute 0.9 kg protein each. The blend is twelve percent protein on a dry basis. With entered prices twenty and five per wet kilogram, its cost is three hundred currency units.
Where this model stops
Entered composition and cost accounting only; no nutrient requirement, digestibility, complete ration or veterinary assessment.
All percentages must use the stated bases. A wet-basis protein label cannot be entered as dry-basis protein without conversion.
A few questions, answered
Can I average the two protein percentages?
Only with equal dry-matter contributions. This table weights by actual dry matter, which can differ greatly from wet mass.
Does low cost per DM mean a feed is suitable?
No. Suitability and other nutritional constraints are outside this composition calculation.