This month we’re focusing on using planning the upcoming grazing season using a grazing chart. Last week we provided free, downloadable grazing charts with questions you can answer to get started with your planning. This week we’re looking at information you need to answer some of those questions.

Here we’ll look at five different ways you can measure and estimate forage production. It goes along with another article this week on figuring animal requirements. We’ve covered all of this in a variety of articles here at On Pasture, so you’ll find a variety of links with additional information.


Ask the Web Soil Survey

If you’re just want a basic idea of what you can expect for your operation based on the soils and environment where you are, check out the Web Soil Survey provided by the Natural Resources Conservation Service. In addition to information about your soils, you’ll find information on what they can do, including how much forage they produce. Head here for instructions on how to get started with this tool.

What Are Your Soils Capable Of?

Using a grazing stick

Estimating how much forage you have available in a pasture is easy when you’ve got a good grazing stick.  Here Grass Whisperer Troy Bishopp shows you how to use one. (Different areas require different measurement sticks. Contact your local Natural Resources Conservation Service office to find out if there is one for your area.)

If you prefer reading about how to use the grazing stick, here’s a great article from Don Ashford.

The Grazing Stick: Tool or Toy?

Using a yard stick

Jim Gerrish shared this method with On Pasture readers. It is based on measuring the height of the pasture and understanding that an inch of pasture can provide a somewhat predictable amount of grazable forage.

Jim writes, “We can bypass measuring the actual pounds per acre of available forage and jump right to an Animal Unit Day/acre yield per inch of forage grazed.”

Here are the values per inch Jim uses:

• 5 animal unit-days/inch of grazable forage per acre for fair pastures, 

• 10 AUD/inch for good pastures, and 

• 15 AUD/inch for excellent pastures.

Now, measure the height of the forage, choose a target residual height and do a calculation.

Now Jim tells us how to do the math. “Let’s say we come up with 14 inches. We decide we want to leave 6 inches which means we plan to remove 8″ of available forage. If we called this a ‘good’ pasture, we would be hoping to remove 80 AUD/acre.”

(8” x 10 AUD/Inch = 80)

That means you could graze eight 1,000 pound cows for one day on one acre.

But what if you’re not raising 1000 pound cows? Let’s say you have a flock of ewes with lambs instead. When you look at the AUD chart you’ll see that one ewe is .17 of an AUD. So how many sheep can you graze on that same acre of pasture?
80 ÷ .17 = 470.58

Remember that you are ESTIMATING. Sources of error include not really having 14 inches of forage, or grazing more or less than 8 inches.

Clipping and weighing

This is the most tedious way to determine how much forage you have. It involves clipping and collecting forage in within a hoop in several sample areas, weighing it, and doing the math to get a pounds per acre estimate. Kiley Whited shows us how in this video.

Ask an expert

If you’re just starting out, working with someone who’s done this before is a great idea.
Your local Natural Resources Conservation Service or Conservation District staff can give you some good starting estimates, and can even help you develop a grazing plan. Cooperative extension service agents are also available in most counties in most states. The extension service is usually associated with a state university and their job is to help folks like you. All of these are free services and many times they can help you learn about other technical and financial assistance.
Another option is to join a state grazing or grassland coalition. You’ll find links to a list of these groups in the Resources and Links section at the end of this ebook. Some of these organizations have established mentoring programs to help fellow graziers. If they don’t have a mentoring program, you’ll at least find experienced graziers who can answer questions and give you an idea of what to expect from forage in your pastures.

Grow this skill

Estimating forage available is not just a once a grazing season thing. It’s something that you’ll need to be able to do throughout the grazing season. The good news is, the more you do it, the better you’ll get. Better yet, you’ll train your eye so that eventually, you’ll be able to estimate what you have simply by walking through your pasture.

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