Calculate the nutrients consumed daily per head. Calculate the final concentrati

ID: 166861 • Letter: C

Question

Calculate the nutrients consumed daily per head. Calculate the final concentration of each nutrient in the total amount consumed daily (as fed basis). You know that copper concentrations can be an issue for sheep above 10 ppm. If levels exceed 20 ppm in total intake, copper toxicity is a major concern, unless molybdenum levels (a copper antagonist) are consumed at levels above 3 ppm (such that the Cu: Mo ratio is less than 10:1). What is the Cu:Mo ratio of your current diet?_____ Are your sheep OK, or are they at risk for Cu toxicity? _____

Explanation / Answer

Answer:

You have 25 sheep wintering on a mixture of 75% grass hay and 25% alfalfa hay (on average consuming 4 Lb hay per head per day as fed). Your neighbor indicates he really likes the supplement below. You put out enough supplement for 30 days but after 20 days you notice it's almost gone, indicating your sheep are consuming more than the 1 oz per day indicated on the label.

Assumptions:

Nutrients in table are presented on as fed basis

1 oz = 28 grams

1 ppm = 1 mg/kg

Use minimum calcium concentration from tag

Number of Sheep = 25

Mixture contains = 75% grass hay and 25% alfalfa hay

Average consumption per head per day = 4 Lb

Nutrients consumed daily per head:

Conversion factor 1 Lb (pound) = 454.6 g

The consumption of nutrient mixture per head per day = 4 Lb = 1818.4 gram

Alfa Alfa hay consumed per head per day = 25% of 1818.4g = 454.6 g

Grass hay consumed per head per day = 75% of 1818.4g = 1363.8 g

Calcium = 1.24% of 456.4g (alfalfa) = 5.65g per head per day

Calcium = 0.37% of 1363.8g (grass hay) = 5.04g per head per day

Magnesium = 0.32% of 456.4 (alfalfa) = 1.46g per head per day

Magnesium = 0.17% of 1363.8g (grass hay) = 2.31g per head per day

Phosphorus = 0.22% of 456.4 (alfalfa) =1.00g per head per day

Phosphorus = 0.23% of 1363.8g (grass hay) = 3.13g per head per day

Copper = 16.09ppm (mg/Kg) of 456.4g (alfalfa) = (456.4*16.09)/1000 = 7.34mg per head per day

Copper = 12.98ppm (mg/Kg) of 1363.8g (grass hay) = (1363.8*12.98)/1000 = 17.70mg per head per day

Molybdenum = 1.75ppm (mg/kg) of 456.4g (alfalfa) = (456.4*1.75)/1000 = 0.798mg per head per day

Molybdenum = 0.75ppm (mg/kg) of 1363.8g (grass hay) = (1363.8*0.75)/1000 = 1.022mg per head per day

Supplement consumed per day per head = 1oz =28gram per day per head

Calcium (supplement) = 12% of 28g = 3.36g per day per head

Magnesium (supplement) = 5% of 28g = 1.4g per day per head

Phosphorus (supplement) = 8% of 28g = 2.24g per day per head

Copper (supplement) = 40ppm (mg/kg) of 28g = (40*28/1000) = 1.12mg per day per head

Molybdenum (supplement) = 100ppm (mg/kg) of 28g = (100*28/1000) =2.8mg per day per head

Final Concentration of each nutrient in the total amount consumed daily (as fed basis)

Calcium = 14.05g in 1846.4 g total feed consumed = (14.05*100)/1846.4 = 0.76%

Magnesium = 5.17g in 1846.4 g total feed consumed = (5.17*100)/1846.4 = 0.28%

Phosphorus = 6.37g in 1846.4 g total feed consumed = (6.37*100)/1846.4 = 0.344%

Copper = 26.16mg in 1846.4 g total feed consumed = (26.16*100)/(1846.4*1000) = 0.0014% = 14PPM

Molybdenum = 4.62mg in 1846.4 g total feed consumed = (4.62*100)/(1846.4*1000) = 0.00025%

Calculate the nutrients consumed daily per head.

Ingredient

Consumed (grams)

Calcium (g)

Mg (g)

P (g)

Cu (mg)

Mo (mg)

As Fed Basis

Alfalfa hay

454.6 g

5.65g

1.46g

1.00g

7.34mg

0.798mg

Grass hay

1363.8 g

5.04g

2.31g

3.13g

17.70mg

1.022mg

Supplement

28g

3.36g

1.4g

2.24g

1.12mg

2.8mg

Total

1846.4g

14.05g

5.17g

6.37g

26.16mg

4.62mg

Calculate the final concentration of each nutrient in the total amount consumed daily (as fed basis).

Calcium (%)

Mg (%)

P (%)

Cu (ppm)

Mo (ppm)

0.76%

0.28%

0.344%

0.0014% (14ppm)

0.00025% (2.5ppm)

You know that copper concentrations can be an issue for sheep above 10 ppm. If levels exceed 20 ppm in total intake, copper toxicity is a major concern, unless molybdenum levels (a copper antagonist) are consumed at levels above 3 ppm (such that the Cu : Mo ratio is less than 10:1).

What is the Cu:Mo ratio of current diet:

Answer: Cu is 14ppm and Mo is 2.5ppm So ratio is 5.6 Cu : 1 Mo

Are your sheep OK, or do you suspect a copper toxicity?

Copper amount in diet is more than 10ppm but less than 20ppm. Some amount of Mo (2.5ppm) in diet is able to maintain the Cu:Mo ratio <10:1 (5.6:1), so Sheep should be fine and Copper toxicity should not occur.