How Much Seleniun is in this Diet?
May 2011 Issue of Forage for Thought
How much total Selenium is in the diet below:
(For international readers, 22 lbs is equivalent to 10 kgs; 1 ounce is equivalent to 28.4 grams; and 2 lbs is equivalent to 0.91 kgs)
Answer:
1. Selenium in 22 lbs of grass hay with 0.05 ppm of Se
22 lbs multiplied by 0.454 = 10 kg (rounded up from 9.99 kg)
0.05 mg/kg (or ppm) X 10 kg = 0.5 mg of Selenium
2. Selenium in 1 ounce of vitamin/mineral supplement that contains 9 ppm of Se
0.454 kg in one pound. 0.454 divided by 16 = 0.0284 kg in one ounce
0.0284 kg X 9 mg/kg (ppm) = 0.26 mg of Se
3. Selenium in 2 lbs of commercial feed that contains 0.6 ppm Se
2 lbs multiplied by 0.454 = 0.91 kg
0.91 kg X 0.6 mg/kg (ppm) = 0.55 mg Se
TOTAL amount of Selenium = 0.5 mg (grass hay) + 0.26 mg (supplement) + 0.55 mg (commercial feed) = 1.31 mg