1. How do you set stocking rate?
Four-step procedure:
Balance supply with demand
Karen Launchbaugh
Rangeland Ecology & Management
University of Idaho

2. 4-Step “Forage Demand” Method
Calculate usable forage
Adjust for accessibility (terrain or water)
Calculate forage demand of animals
Calculate stocking rate
The forage demand method is used:
When you have no stocking information from previous years.
To estimate carrying capacity in biological surveys or land appraisals.
When considering changes in kind or class of animals.

3. Step 1 - Calculate Usable Forage:
Mollie Texan has a ranch in the southern mixed prairie that is 1,000 acres big. 75% of it is covered by a sandy loam range site that produces 1,500 lb/acre/year. The other 25% is a shallow uplands site that produces 800 lb/acre/year. How much total forage does Mollie produces on her ranch?
An example – Mollie Texan

4. Step 1 - Calculate Usable Forage:
Mollie Texan has a ranch in the southern mixed prairie that is 1,000 acres big. 75% of it is covered by a sandy loam range site that produces 1,500 lb/acre/year. The other 25% is a shallow uplands site that produces 800 lb/acre/year. How much total forage does Mollie produce on her ranch?
An example – Mollie Texan

5. Step 1 - Calculate Usable Forage:
However Mollie cannot use all of the forage she produces. Why?
An example – Mollie Texan

6. Step 1 - Calculate Usable Forage:
However Mollie cannot use all of the forage she produces. Why?
Not all the vegetation can be eaten by animals… it isn’t all “forage”
Need to leave some vegetation for soil health
Want to leave some for other animals in ecosystem like wildlife
Need to leave some leaves so the plants can photosythensize and recover from the disturbance
An example – Mollie Texan

7. Step 1 - Calculate Usable Forage:
Mollie cannot use all of the forage she has on her ranch. Scientists recommend that Mollie remove only 40-50% of her total forage in order to maintain good range condition. If Mollie decides to use 40% of her total forage, how much usable forage does she have?
An example – Mollie Texan

8. Step 1 - Calculate Usable Forage:
Mollie cannot use all of the forage she has on her ranch. Scientists recommend that Mollie remove only 40-50% of her total forage in order to maintain good range condition. If Mollie decides to use 40% of her total forage, how much usable forage does she have?
An example – Mollie Texan

9. Step 2- Account for Accessibility
Adjustments often need to be made because not all the available forage on the range is actually accessible by animals.
May be too far from water -- it depends on:
Animal species, age, condition and experience
Season of year
Terrain
Vegetation may be growing on areas too steep for animals to use easily – it depends on :
An example – Mollie Texan
In this example… no accessibility issues.

10. Step 3- Calculate Forage Demand
Mollie has several species that she manages on her ranch.
She has 4 horses that weigh about 1200 lbs each.
She also wants to allow enough forage for 15 pronghorn antelope weighing about 110 pounds each.
The rest of her forage she want to use with sheep that weigh about 180 lbs each.
How much forage will her horses need for 1 year?
How much forage will the 15 pronghorn eat on her ranch?
How much forage will 1 sheep eat each year?
An example – Mollie Texan

11. Step 3- Calculate Forage Demand
Mollie has several species that she manages on her ranch.
She has 4 horses that weigh about 1200 lbs each.
She also wants to allow enough forage for 15 pronghorn antelope
The rest of her forage she want to use with sheep that weigh about 180 lbs each.
How much forage will her horses need for 1 year?
How much forage will the 15 pronghorn eat on her ranch?
How much forage will 1 sheep eat each year?
An example – Mollie Texan

12. Step 3- Calculate Forage Demand
Mollie has several species that she manages on her ranch.
She has 4 horses that weigh about 1200 lbs each.
She also wants to allow enough forage for 15 pronghorn antelope
The rest of her forage she want to use with sheep that weigh about 180 lbs each.
How much forage will her horses need for 1 year?
How much forage will the 15 pronghorn eat on her ranch?
How much forage will 1 sheep eat each year?
An example – Mollie Texan

13. Step 3- Calculate Forage Demand
Mollie has several species that she manages on her ranch.
She has 4 horses that weigh about 1200 lbs each.
She also wants to allow enough forage for 15 pronghorn antelope
The rest of her forage she want to use with sheep that weigh about 180 lbs each.
How much forage will her horses need for 1 year?
How much forage will the 15 pronghorn eat on her ranch?
How much forage will 1 sheep eat each year?
An example – Mollie Texan

14. Step 4- Calculate Stocking Rate
We need to determine how many sheep Mollie should put on her ranch. From Step 1 we calculated that Mollie had 530,000 lbs of forage to use. Reduce this amount by the amount need for horses. Reduce this amount for the pronghorn: How many sheep should she stock year long if each sheep eats 1,642.5 lbs/year? _______ lbs forage ÷ _____lbs/sheep = ____ sheep/year
An example – Mollie Texan

15. Step 4- Calculate Stocking Rate
We need to determine how many sheep Mollie should put on her ranch. From Step 1 we calculated that Mollie had 530,000 lbs of forage to use. Reduce this amount by the amount need for horses: Reduce this amount for the pronghorn: How many sheep should she stock year long if each sheep eats 1,642.5 lbs/year? _______ lbs forage ÷ _____lbs/sheep = ____ sheep/year
An example – Mollie Texan

16. Step 4- Calculate Stocking Rate
We need to determine how many sheep Mollie should put on her ranch. From Step 1 we calculated that Mollie had 530,000 lbs of forage to use. Reduce this amount by the amount need for horses: Reduce this amount for the pronghorn: How many sheep should she stock year long if each sheep eats 1,642.5 lbs/year? _______ lbs forage ÷ _____lbs/sheep = ____ sheep/year
An example – Mollie Texan

17. Step 4- Calculate Stocking Rate
We need to determine how many sheep Mollie should put on her ranch. From Step 1 we calculated that Mollie had 530,000 lbs of forage to use. Reduce this amount by the amount need for horses: Reduce this amount for the pronghorn: How many sheep should she stock year long if each sheep eats 1,642.5 lbs/year? _______ lbs forage ÷ _____lbs/sheep = ____ sheep/year
An example – Mollie Texan

18. Step 4- Calculate Stocking Rate
A proper stocking must include three elements:
Number of animals or animal units
Area of land
Time for grazing
In this example our stocking rate was:
282 sheep/1,000 ac/year
Stocking rates are usually described in AUMs (Animal Units Months) as AUMs per acre (AUM/Ac)
or Acres per AUM (Ac/AUM)
What would our stocking rate of
282 sheep/1000 ac/year be in AUMs/Ac?
An example – Mollie Texan

19. Step 4- Calculate Stocking Rate
282 sheep/1000 ac/year in AUM/Ac?
5 sheep = 1 Animal Unit (AU) so we have AU’s.
There are 12 months per year so we multiply AU’s by 12 to get _ __ AUM’s. (Note: If you had 1 animal unit for a whole year, you would need 12 AUM’s of forage).
So we have _ AUMs/1000 acres, so divide by 1000 to get _ AUMs/Ac.
Or to get Ac/AUM = 1000 ac/ AUMs = _ _ Ac/AUM.
An example – Mollie Texan

20. Step 4- Calculate Stocking Rate
282 sheep/1000 ac/year in AUM/Ac?
5 sheep = 1 Animal Unit (AU) so we have AU’s.
There are 12 months per year so we multiply AU’s by 12 to get _677__ AUM’s. (Note: If you had 1 animal unit for a whole year, you would need 12 AUM’s of forage).
So we have _ AUMs/1000 acres, so divide by 1000 to get _ AUMs/Ac.
Or to get Ac/AUM = 1000 ac/ AUMs = _ _ Ac/AUM.
An example – Mollie Texan

21. Step 4- Calculate Stocking Rate
282 sheep/1000 ac/year in AUM/Ac?
5 sheep = 1 Animal Unit (AU) so we have AU’s.
There are 12 months per year so we multiply AU’s by 12 to get _677__ AUM’s. (Note: If you had 1 animal unit for a whole year, you would need 12 AUM’s of forage).
So we have _677 AUMs/1000 acres, so divide by 1000 to get _.677 AUMs/Ac.
Or to get Ac/AUM = 1000 ac/ 677 AUMs = _ _ Ac/AUM.
An example – Mollie Texan

22. What if scenario An example – Mollie Texan
What if Mollie decides to stock her ranch with stocker steers instead of sheep?
Suppose Mollie wants to buy steers weighing 600 lbs April 1st and then sell them June 30 when they weigh about 800 lbs.
How much will each steer eat a day (average for the whole period)?
How much will each steer need for the 3 month grazing period?
How many steers should Mollie stock?
An example – Mollie Texan

23. What if scenario An example – Mollie Texan
What if Mollie decides to stock her ranch with stocker steers instead of sheep?
Suppose Mollie wants to buy steers weighing 600 lbs April 1st and then sell them June 30 when they weigh about 800 lbs.
How much will each steer eat a day (average for the whole period)?
How much will each steer need for the 3 month grazing period?
How many steers should Mollie stock?
An example – Mollie Texan

24. What if scenario An example – Mollie Texan
What if Mollie decides to stock her ranch with stocker steers instead of sheep?
Suppose Mollie wants to buy steers weighing 600 lbs April 1st and then sell them June 30 when they weigh about 800 lbs.
How much will each steer eat a day (average for the whole period)?
How much will each steer need for the 3 month grazing period?
How many steers should Mollie stock?
An example – Mollie Texan

25. How do you set stocking rate?
Four-step procedure:
Balance supply with demand
Karen Launchbaugh
Rangeland Ecology & Management
University of Idaho