Example #1 

Feed 

Cu Content 

Feed Intake 

Forage 

4 ppm 

28 lbs 

Mineral Premix 

2200 ppm 

0.25 lbs (4 oz) 

 

Convert all concentrations to metric units. 

  1. 1 lb = 0.454 kg 
  2. 1 oz = 28.35 g 
  3. Forage intake = 28 lbs × 0.454 kg/lb = 12.7 kg 
  4. Mineral premix = 0.25 lbs × 0.454 kg/lb = 0.11 kg 

 Convert ppm to mg/kg 

  1. 1 ppm = 1 mg/kg 
  2. Forage = 4 mg/kg 
  3. Mineral = 2200 mg/kg

Calculate Copper intake in milligrams for forage and mineral.  Equation = DMI × Cu concentration 

  1. Forage intake: 12.7 kg × 4 mg/kg = 50.8 mg 
  2. Mineral intake: 0.11 kg × 2200 mg/kg = 242 mg 
  3. Total Cu intake per day: 50.8 + 242 mg = 292.8 mg Cu/d 

 Do we meet the daily requirement for copper? 

  1. Total DMI per day: 12.7 + 0.11 = 12.81 kg 
  2. Amount Cu consumed per kg DMI consumed: 292.8 mg Cu ÷ 12.81 kg = 22.9 mg/kg 
  3. Cu requirement is 10 ppm. 
  4. Requirement is met.

 Example #2 

Feed 

Cu Content 

Feed Intake 

Forage 

10 ppm 

30 lbs 

Mineral Premix 

0.01 % 

0.5 lbs 

 

Convert all concentrations to metric units. 

  1. 1 lb = 0.454 kg 
  2. 1 oz = 28.35 g 
  3. Forage intake = 30 lbs × 0.454 kg/lb = 13.6 kg 
  4. Mineral premix = 0.5 lbs × 0.454 kg/lb = 0.227 kg 

 

Convert ppm to mg/kg 

  1. 1 ppm = 1 mg/kg 
  2. Forage = 5 mg/kg 

 

Convert % to mg/kg 

  1. Multiply by 10,000 
  2. 0.01% = 100 mg/kg 

 

Calculate Copper intake in milligrams for forage and mineral.  Equation = DMI × Cu concentration 

  1. Forage intake: 13.6 kg × 10 mg/kg = 136 mg 
  2. Mineral intake: 0.227 kg × 100 mg/kg = 22.7 mg 
  3. Total Cu intake per day: 136 + 22.7 = 158.7 mg Cu/d 

 

Do we meet the daily requirement for copper? 

  1. Total DMI per day: 13.6 + 0.227 = 13.83 kg 
  2. Amount Cu consumed per kg DMI consumed: 158.7 mg Cu ÷ 13.83 kg = 11.48 mg/kg 
  3. Cu requirement is 10 ppm. 
  4. Requirement is met. 

Example #3 

Feed 

Cu Content 

Feed Intake 

Forage 

5 ppm 

30 lbs 

Supplement 

250 mg/lb 

5 oz. 

 

Convert mg/lb to mg/kg 

  1. 250 mg/lb ÷ 0.454 kg/lb = 550.7 mg/kg 

 

Calculate Copper intake in milligrams for forage and mineral.  Equation = DMI × Cu concentration 

  1. Forage intake = 30 lbs × 0.454 kg/lb = 13.6 kg 
  2. Forage intake: 13.6 kg × 5 mg/kg = 68 mg 
  3. Supplement intake: 0.142 kg × 550.7 mg/kg = 78.2 mg 
  4. Total Cu intake per day: 68 + 78.2 = 146.2 mg Cu/d 

Do we meet the daily requirement for copper with the supplement? 

  1. Total DMI per day: 13.6 + 0.142 = 13.74 kg 
  2. Amount Cu consumed per kg DMI consumed: 146.2 mg Cu ÷ 13.74 kg = 10.64 mg/kg 
  3. Cu requirement is 10 ppm. 
  4. Requirement is met