“Selenium” Quiz
January 2011 Issue of Forage for Thought
Answers and explanations shown below
1. Selenium works with which one of the following nutrients as an “antioxidant team?”
a. Vitamin A
b. Magnesium
c. Vitamin E
d. Silica
e. Copper
2. Selenium protects the inside of the cell against oxidative damage as part of this enzyme:
a. Lipase
b. Superoxide dismutase
c. Alcohol dehydrogenase
d. Glutathione peroxidase
e. Pepsin
3. A secondary function of selenium is:
a. Bone production
b. Thyroid hormone metabolism
c. Protein digestion
d. Serotonin production
4. Fortified feeds typically supplement 0.6 ppm of selenium. If you feed 4 lbs of this feed, how many mg of selenium is your horse getting?
a. 6 mg
b. 24 mg
c. 240 mg
d. 1.09 mg
e. 2.4 mg
5. Selenium can be highly toxic at relatively low dosages. A safe range for a full-sized horse (approximately 1100 lbs) would be:
a. 1 to 5 mg per day
b. 3 to 20 mg per day
c. 5 to 50 mg per day
d. No more than 100 mg per day
6. A selenium toxicity can result in a condition known as “Blind Staggers.”
a. True
b. False
7. If selenium is consumed at a slightly high level for a period of time, the chronic condition is known as alkali disease. This is characterized by all but one of the following:
a. Hair loss along the mane and tail
b. Hooves will crack around the coronary band
c. Mouth ulcerations
8. You can tell how much selenium is in hay by its smell, color, and texture.
a. True
b. False
9. Soils in parts of the U.S., such as the northeast, Ohio valley, Florida, and northwestern states, tend to have low levels of selenium. Symptoms of a selenium deficiency include all but one of the following:
a. Muscle weakness
b. Respiratory distress
c. Difficulty moving
d. Hooves will crack around the coronary band.
10. Before adding a fortified feed or selenium supplement, it is important to know the total amount of selenium in the entire diet.
a. True
b. False
All of these questions are discussed in detail in Chapter 5 – Fundamentals of Minerals in Feed Your Horse Like A Horse.
Answers:
1. C
2. D
3. B
4. D
5. A
6. A
7. C
8. B
9. D
10. A
1. Selenium works with which one of the following nutrients as an “antioxidant team?”
a. Vitamin A
b. Magnesium
c. Vitamin E
d. Silica
e. Copper
“C” is the correct answer. Vitamin E acts as the first line of defense, protecting the outside of the cell (cell membrane) while selenium protects the inside of the cell.
2. Selenium protects the inside of the cell against oxidative damage as part of this enzyme:
a. Lipase
b. Superoxide dismutase
c. Alcohol dehydrogenase
d. Glutathione peroxidase
e. Pepsin
“D” is correct. Selenium is part of glutathione peroxidase – an enzyme that exists inside the cell that serves as an antioxidant.
3. A secondary function of selenium is:
a. Bone production
b. Thyroid hormone metabolism
c. Protein digestion
d. Serotonin production
“B” is correct. Selenium is necessary for T3 synthesis.
4. Fortified feeds typically supplement 0.6 ppm of selenium. If you feed 4 lbs of this feed, how many mg of selenium is your horse getting?
a. 6 mg
b. 24 mg
c. 240 mg
d. 1.09 mg
e. 2.4 mg
“D” is correct. To calculate:
First convert lbs to kg: 4 lbs X .454 kg/lb = 1.816 kg
Next, multiple by ppm (same as mg/kg) to get the mg of selenium: 1.816 kg X 0.6 mg/kg = 1.09 mg of selenium
5. Selenium can be highly toxic at relatively low dosages. A safe range for a full-sized horse (approximately 1100 lbs) would be:
a. 1 to 5 mg per day
b. 3 to 20 mg per day
c. 5 to 50 mg per day
d. No more than 100 mg per day
“A” is correct. Selenium is best fed at 1-3 mg for the horse with average activity and up to 5 mg per day for the athlete.
6. A selenium toxicity can result in a condition known as “Blind Staggers.”
a. True
b. False
“A” is correct. Blind staggers is characterized by colic, diarrhea, increase heart and respiration rate, and apparent blindness.
7. If selenium is consumed at a slightly high level for a period of time, the chronic condition is known as alkali disease. This is characterized by all but one of the following:
a. Hair loss along the main and tail
b. Hooves will crack around the coronary band
c. Mouth ulcerations
“C” is the one that is not true.
8. You can tell how much selenium is in hay by its smell, color, and texture.
a. True
b. False
“B” is correct. The only way to know how much selenium a grass or legume hay contains is to have it analyzed.
9. Soils is parts of the U.S., such as the northeast, Ohio valley, Florida, and northwestern states, tend to have low levels of selenium. Symptoms of a selenium deficiency include all but one of the following:
a. Muscle weakness
b. Respiratory distress
c. Difficulty moving
d. Hooves will crack around the coronary band.
“D” is the only one that is not true. Hoof cracks describe a selenium toxicity, not a deficiency.
10. Before adding a fortified feed or selenium supplement, it is important to know the total amount of selenium in the entire diet since selenium should not exceed 0.6 ppm (mg/kg).
a. True
b. False
“A” is correct. Since the range of safety is so narrow, it is important to evaluate selenium from all sources.