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Pearson square example one

Step 1: The value in the middle MUST be intermediate between the two values used in the left side of the square.  In this example, 11% is the CP requirement for the animals.  Chopped hay has 12.25% CP and corn silage has 10.8% CP. 

 Step 2: Disregard any negative numbers during subtraction. 

 Step 3: Subtract the nutrient value from the nutrient requirement on the diagonal. 

 Step 4: Add the parts of each ingredient and divide by the total to calculate the percent of the ration that each ingredient will represent. 

Chopped Hay: (0.2 ÷ 1.45) × 100 = 13.8% 

Corn Silage: (1.25 ÷ 1.45) × 100 = 86.2% 

 Step 5: Check the calculation: 13.8 lb chopped hay × 12.25% CP = 1.69 lb CP 

  86.2 lb corn silage × 10.8% CP = 9.31 lb CP

Pearson square exmaple two

CP requirement for replacement heifers = 9.8% CP 

1400 lb mature weight 

Currently weighs 1020 lbs 

BCS 5 

Gaining 2 lb/d 

 Step 4: Add the parts of each ingredient and divide by the total to calculate the percent of the ration that each ingredient will represent. 

Hay: (30.2 ÷ 31.05) × 100 = 97.3% 

Supplement: (0.85 ÷ 31.05) × 100 = 2.7% 

 Step 5: Check the calculation: 97.3 lb hay × 8.95% CP = 8.71 lb CP 

   2.7 lb supplement × 40% CP = 1.08 lb CP 

 Heifers eating 2% of BW per day 

20.4 lbs DM/day 

Hay: 20.4 lbs × 97.3% = 19.8 lbs hay DM per day 

Supplement: 20.4 lbs × 2.7% = 0.55 lbs supplement DM per day

 

Example 3: Using More than 2 Ingredients 

  • Preparing a 15% CP mixture 
  • Supplement  
  • 50% Soybean meal with 54% CP 
  • 50% Corn gluten feed with 24% CP 
  • Grain mixture 
  • 60% Corn grain with 10% CP 
  • 40% Soyhulls with 12% CP 

 

Step 1: Calculate CP in the Supplement 

50% SBM × 54% CP = 27% CP 

50% CGF × 24% CP = 12% CP 

 Step 2: Calculate CP in the Grain 

60% Corn × 10% CP = 6% CP 

40% Soyhulls × 12% CP = 4.8% CP 

 Step 3: Pearson Square 

Pearson square example 3