How it works
The Pearson square is the classic pencil method for mixing two feeds to hit one target, usually crude protein. Put the target in the middle of a square. Subtract diagonally, ignoring minus signs, and the differences tell you how many parts of each feed to use. It only works when the target sits between the two feeds.
How to use it
Use the protein figures from each feed's tag or a lab test, both on the same basis. Example: for 16% from soybean meal (44%) and corn (9%), use 7 parts soybean meal to 28 parts corn, which is 20% and 80%.
Reference chart
| Feed | Typical crude protein (as fed) |
|---|---|
| Soybean meal | 44–48% |
| Alfalfa hay | 15–20% |
| Oats | about 11–12% |
| Barley | about 11–12% |
| Corn | about 8–9% |
| Grass hay | 7–12% |
Frequently asked questions
How does the Pearson square work?
Write the target in the center and the two feeds on the left corners. Subtract each feed from the target across the diagonal, ignoring signs. Each result is the parts of the feed on the opposite corner.
Can I use it for more than two feeds?
Not directly. Group feeds into two blends first (for example, a fixed grain mix and a protein supplement), then square those two.
Why does the target have to be between the two feeds?
You can't mix two feeds that are both below 16% protein and get 16%. One feed has to be above the target and one below.
Does it balance energy and minerals too?
No, one nutrient at a time. Check energy, calcium, phosphorus and minerals separately, or ask a nutritionist for a full ration.
Figures are typical values from university extension and breed-association guidance. Estimates only. Individual animals vary — confirm pregnancy and health questions with your veterinarian. Last reviewed 2026-09-18.