Pasture Algebra Tutorial

Answers
1. What formulas do I use? Where do I find the formulas?
All of the formulas and information such as grazing efficiency, and intake rate in % of body weight can be found on the grazing stick page, or on a grazing stick. The main formula you will use is here:
(Total Forage/Acre) x (Acres) x (% Grazing efficiency)
Days =
(Animal Wgt) x (Intake Rate in % of Body Wgt) x ( # of Animals)

2. I think I have the correct answer but am not getting anywhere.
Are you typing it in an X.X format? For example an answer of 0.5 would work, or 5.678 would be rounded to 5.7. Do not round numbers off before finding the final answer. A pasture 4 inches or below should not be grazed and will result in a negative number or 0. If this occurs the answer is 0.0- this pasture should not be grazed at this time. See Answer # 5

3. How do I find the total forage/acre?
To find the Total Forage/ Acre, first determine the percent coverage. Next find the Pounds per Acre Inch, use the percent coverage & the Forage type to determine the range. Take an average of the range. To take an average, add both numbers and divide by two. Multiple this number by the inches of forage - 4. This is the Total Forage/ Acre.

4. How do I determine the percent coverage?
Percent Coverage is a measurement of the amount of soil covered by forage. If there is no visible soil in the majority of the pasture, then the pasture is labeled > 90 % coverage. If there are a few bare spots, or the forage is thin, then it is labeled 75-90 % coverage. A < 75 % coverage will have more bare spots, and the forage is extremely thin. Erosion may be a problem in this field. Example pictures are found on the grazing stick page by clicking on the percent coverage labels. To determine the percent coverage use the pictures of the forage in the pasture.

5. Why shouldn't I graze when the forage is less than 4 inches?
Depending on the forage type you could drastically reduce future yields or even damage the pasture beyond repair. A pasture which has been grazed to this point will often require complete reseeding. Occasionally a paddock in this condition has been "sacrificed" during periods when forages are growing slowly and the producer needs a place to feed hay in.

6. I would like to see an example worked out.
Follow the steps below: a. First collect the following data; pasture height, percent coverage, forage type, species type, pasture, size, number of paddocks, % grazing efficiency, average animal weight, intake rate (as % of body weight), number of animals.

Pasture Height	12 inches	Percent Coverage	75-90 %
Forage Type	Bluegrass	Species Type	Dry Dairy Cows
Pasture size	50 acres	Number of Paddocks	40
% Grazing Efficiency	75 %	Average Animal Weight	1100 lbs.
Intake Rate (as & of body weight)	2 %	Number of Animals	65

d. Fill in the formula.
2600 x 1.25 x .75
Days =
1100 x .02 x 65
Then do the math!
2437.5
Days =
1430

Days = 1.70 days per paddock ( 1 day & ~17 hours)

	Return to Algebra Pages
Beef Cattle	Dairy Cattle	Goat	Horse	Sheep