East vs. West Stocking Rates

As one moves from east to west across the United States, precipitation declines, especially after you cross the 100th meridian.  With this decline in average annual precipitation, plant species change–there are less trees and different species of grasses and broadleaved plants.  This change can easily be seen on a satellite image of the earth; west of the line colors tend to be in the brown family, while on the east side of the line, colors are more in the green family.  Because of the difference in plant species, time and timing of precipitation, and amount of precipitation the number of animals that you can sustainably graze on a piece of land throughout the year differ greatly.  To determine how many animals you can graze on a piece of land, you will need to know two things, 1) how much forage the particular animal will consume, and 2) how much forage is available.

The 100th Meridian of the United States (Photo Google Earth)

The 100th Meridian of the United States (Photo Google Earth)

 

When comparing different livestock grazing systems it is necessary to convert all units to a common language.  To do this we use what is known as an animal unit month (AUM).  An AUM is the measure of forage required by an animal for 1 month, which in most cases is defined as 760-800 pounds depending on what land management agency you are working with.  An animal is defined as one, 1000 pound cow or her equivalent.  See the chart below for the equivalent definition.  This allows us to compare different types of animals as well as different sizes of animals in the same grazing system.  Let us look at two different systems–one found on the east side of the 100th Meridian and one found on the west.

Animal Unit Equivalent Chart (University of Wyoming Extension)

Animal Unit Equivalent Chart (University of Wyoming Extension)

 

Jasper County, Missouri is located in the Southwest corner of the state. It is characterized as a loamy upland prairie.  Its elevation is 1000-1700 feet above sea level.  It has an average annual precipitation of 41-45 inches and its growing season is 195-225 days long.  The soils in the county are characterized as deep to very deep, moist but well-drained, and medium to fine textured.  The annual vegetation production is 5,000-10,000 pounds per acre depending on soil type and precipitation.  Native grasses include big bluestem, little bluestem, Indian grass, and switch-grass.

Jasper County is located in Southwest Missouri.

Jasper County is located in Southwest Missouri.

 

On the west side of the 100 Meridian is Converse County, Wyoming.  It is located in the East Central part of the state, in the Northern Prairie, and has an elevation of 2950-5900 feet above sea level.  Its average annual precipitation is 9-14 inches, with a growing period of 145-170 days.  Soils are characterized as shallow to very deep, dry, well drained, and medium to fine textured. Annual forage production is 700-2,000 pounds per acre depending on soil type and precipitation.  Native grasses include rhizomatous wheatgrasses, green needle, needleandthread, and blue grama.

Converse County is located in East Central Wyoming.

Converse County is located in East Central Wyoming.

 

So let us just say we had 10 acres of land in each of these counties.  How many 1000 lb cows could we graze for one month?

Jasper County, Missouri
Forage production = 7,000 lbs/acre/year
Forage for 1 month = 5,833lbs
We will use 60% of the forage (40% is left for the wildlife and to ensure plant health) = 3,500lbs
Animal Units (or 1000 lb cows) = 3500/800 = 4 cows
We could graze 4 cows for 1 month on 10 acres

A Missouri rancher moves cattle and sheep from one paddock to another (Photo: NRCS)

A Missouri rancher moves cattle and sheep from one paddock to another (Photo: NRCS)

 

Converse County, Wyoming
Forage production = 1,000lbs/acre/year
Forage for 1 month = 833lbs
We will use 40% of the forage (60% is left for wildlife and to ensure plant health) = 333lbs
Animal Units (or 1000 lbs cows) = 333/800 = 0.5 cows
We could only graze 1/2 a cow for 1 month on 10 acres; or we would need 20 acres to graze 1 cow for 1 month; or we could graze 1 cow for 15 days on 10 acres.

Cattle graze out across the Wyoming plains (Photo: Morgan Hays, Converse County Extension).

Cattle graze out across the Wyoming plains (Photo: Morgan Hays, Converse County Extension).

 

Stocking rates differ greatly depending on forage production which is determined by the amount and timing of precipitation, plant species present, and soil type.  Figuring stocking rates is fairly easy once you get the hang of it and is one of the more important tasks in a successful livestock production system.  Forage production and stocking rate records are critical in making timely management decisions. If you need assistance in calculating your stocking rate be sure to contact your local University Extension Office.

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Rangeland Monitoring: Piece of Cake

I was offering a rangeland monitoring class this week but because of the wonderful rain it was canceled.  Rangeland monitoring is best done as a hands on activity.  Yes, I was disappointed, but I am not one to complain about the rain.  While I was working on rescheduling this class I was visiting with a livestock producer who told me that rangeland monitoring was just more paperwork so learning about range monitoring wasn’t in the plan.  As you can imagine, since I am a range nerd and all, this made my hackles rise up just a bit and I feel like addressing the comment, so you get another blog post!  I’d say it was a win-win!

The Red Desert Ranch in Wyoming (Photo by Randy C. Bunney; CC 3.0)

The Red Desert Ranch in Wyoming (Photo by Randy C. Bunney; CC 3.0)

 

It has been my observation that most livestock producers do a great job at keeping livestock performance and tax records; however many do not actually monitor the most important resource on the property–the vegetation–which supports the ranch enterprises.  Typically when producers visit with me and complain about having more paperwork, I give them a simple answer:  Plants are the primary producers on your ranch–they convert solar energy which is free, into usable energy that fuels your livestock, why would you not want to ensure their health?  Answers to this question vary, but the answer is not that important.  What is important is understanding how rangeland health can affect your overall business.

The Grant-Kohrs Ranch near Dear Lodge, Montana (Photo National Park Service).

The Grant-Kohrs Ranch near Dear Lodge, Montana (Photo by: National Park Service).

 

Tracking animal performance, as I have mentioned, is something most producers willingly do, but did you know that it can take several years for animal performance to show a decline in rangeland condition?  This is because animals are smart and they will compensate by selecting less preferred but equally as nutritious plants.  Also years with above average precipitation will typically show an increase in animal performance and can mask the decline in forage condition.  By the time animal performance shows a decline due to resource decline, pastures may have been degraded to the point where full recovery may take years and may be very expensive.

The Gifford Ranch in Capitol Reef National Park in Utah (Photo: National Park Service)

The Gifford Ranch in Capitol Reef National Park in Utah (Photo by: National Park Service)

 

In my observance range monitoring is only as time consuming as you make it and can be fairly easy if approached in the right way.  There are some instances where extensive monitoring may be necessary but in most cases the simple approach can provide enough indication of rangeland condition to help you make appropriate grazing decisions.  Most rangeland monitoring records can be kept in your National Beef Cattleman’s Association Redbook or equivalent, where you keep your livestock records.  They can be kept on your calendar where you keep your rotational grazing schedule.  They can even be kept on your smart phone.  Bottom line: where ever is easiest for you to keep your livestock records is a perfect place to keep basic rangeland monitoring records.

Blue skies over a ranch in Canada (Photo: Public Domain)

Blue skies over a ranch in Canada (Photo: Public Domain)

 

Let’s look at the simple approach. I believe there are 4 different types of records you need to keep for simple rangeland monitoring that can help you make decisions and track rangeland condition.

  1. Take photos while checking the fence lines.  Landscape photos that show forage growth, taken annually can be really helpful when referring to the condition of each pasture.  Almost everyone has a camera phone these days–there are no excuses.
  2. Make a list of plants found in each pasture annually–this gives you the ability to know if an invader species are present and in what amounts.  This is easy to do when checking livestock or water sources.  You don’t have to even know the name of the plant.  You can call it whatever you want, just so you know what it is and how to recognize it, especially the bad ones.
  3. Maintain precipitation records.  This can help you understand how the timing and amount of precipitation can affect forage growth.
  4. Keep stocking rate and grazing duration records for each pasture.  They can help you determine where overgrazing may be occurring or where grazing may be affecting the plant types found in that pasture.
Horses graze on a South Dakota Ranch (Photo: Public Domain)

Horses graze on a South Dakota Ranch (Photo: Public Domain)

 

There you have it! Four easy steps to a range monitoring program.  Again some instances may require more in-depth monitoring, especially if you want to answer specific questions.  Be sure to contact your local Extension Office if this is the case.  They will likely be more than happy to help you out.  So guess what, the “too much paperwork” or “too little time” excuses may not work for you anymore.  Rangeland monitoring typically takes no more time than checking a fence or water source, but will provide you with information on the health of one of the most important resources on your ranch–the vegetation.

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