How to use Pearson Square?

Make your own feeds with balance nutrients for your poultry, swine and ruminants.

List of Contents
I. What is Pearson Square?
II. How to use Pearson Square?
II. Example on how to calculate feed ingredients using Pearson Square.

What is Pearson Square?

The Pearson Square is a simple mathematical tool used in animal nutrition to calculate the proportion of two or more feed ingredients needed to meet specific nutrient requirements.

It is named after its inventor, Professor Karl Pearson, a English mathematician and statistician who developed the square in the late 19th century. The square is represented as a two-by-two matrix, with each corner representing a different feed ingredient and the center indicating the target nutrient concentration.

How to use Pearson Square?

To use the Pearson Square, the nutrient concentrations of the feed ingredients are first determined. Then, the desired nutrient concentration is identified and placed in the center of the square. The nutrient concentrations of the feed ingredients are then placed in the appropriate corners of the square. By algebraically manipulating the equations, the proportions of each feed ingredient required to meet the target nutrient concentration can be determined.

The Pearson Square is a useful tool for animal nutritionists and livestock producers to optimize feed formulation and ensure that their animals receive a balanced diet.

Example on how to calculate feed ingredients using Pearson Square:

How to use the Pearson Square to calculate the proportions of two feed ingredients needed to meet a specific nutrient requirement:

Let's say you want to formulate a feed mix for chickens that contains 18% protein, using two available feed ingredients: cornmeal, which contains 8% protein, and soybean meal, which contains 48% protein.

Pearson Square Sample

On the above illustration shows how Pearson Square being use on two feed ingredients. In the example, Cornmeal with 8% protein was subtracted diagonally with 18% desired protein in a ration. The same with the Soya meal which 48% protein of Soya meal was subtracted diagonally to the 18% desired protein in a ration. 

After getting the parts of each feed ingredients, each parts will be divided into the sum of each parts and times the results by 100 to get the percentage of each parts in a ration. In this case, Cornmeal needs 75% parts and Soya at 25% parts to have 18% protein in a ration of chickens.