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New Range Management Tool on Wyoming Ranch Tools Website

by Wyoming Livestock Roundup

Economists often complain that all animal scientists or range scientists want to talk about is economics. Well, I am turning the tables in this article. I am an economist, but I am talking about range management today. However, my co-author is a range scientist.

Range management can be a challenge in Wyoming, as Mother Nature can often be quite tricky to deal with. This summer, northern Wyoming is short on moisture and grass, while here in southwest Wyoming, we are having an amazing grass year.

Grazing plans are an important component of ranch management. An understanding of grazing fundamentals gives us a foundation on which to plan. Successful ranch managers strive for sustainable use of their forage resources. It is critical that the frequency, intensity and season of use that grazing occurs be thought out and managed for the health of the plants and livestock performance.

Frequency, the number of times a plant is grazed, can influence a plants ability to regrow. Plants grazed often may not be able to replace photosynthetic tissues during the growing season. Intensity, the amount of plant tissue removed, impacts plant health as well. However, if the grazing is done during dormant phases of plant growth, even high intensity grazing may have little impact. This timing, or season of use of the grazing, is the third component of the basics of grazing from a plant health perspective. Grazing plans should take care to ensure that some pastures are not subjected to too high of frequencies and/or intensities during critical plant growth stages.

Grazing plans should consider previous years’ use on pastures when planning for future years. Current years’ growing season precipitation is another critical planning tool for grazing plans. Ranch managers should monitor precipitation and available irrigation. Grazing plans should also include what do to in the case of drought. Drought plans may include partial destocking, purchase of additional feeds and pasture and increased attention to both plant health and livestock performance.

Most pastures on a ranch have had some previous livestock use. With records of what class, age and weight of animals grazed and for how long they were in the pasture, producers can estimate how much forage the livestock harvested and use that figure to estimate what the overall production of that pasture was.

Although the formulas for making these calculations have been around for quite some time, they have not been in a user-friendly online tool. With this in mind, we developed the latest tool on the Wyoming Ranch Tools Website at The tool is the “Stocking Rate” tool on the website and is really three to four calculators in one.

The first calculator on the page allows you to estimate total production per acre from past use records. The user enters in the number of head, average weight per head, days in pasture, acres in pasture and an estimate of the percent utilization. The calculator then provides the total animal unit months (AUMs) harvested, AUMs per acre, pounds consumed per acre and total production per acre.

Once you generate the total production per acre you can use the second calculator, which helps you estimate a stocking rate. The user enters the total production per acre, pasture utilization percentage, average weight per head, number of months the pasture is to be grazed and the acres in the pasture. The calculator then generates the forage availability for grazing, a one-month capacity given the weight of the animals and the number of animals that can be grazed for the intended grazing period.

The final calculator on the page helps to estimate a grazing season. Again, the user enters total production per acre, pasture utilization percentage, average weight per head, number of head and acres in the pasture. The calculator then provides the forage available for grazing and the months of grazing available for the specified animals.

A second tool is available under the clip-and-weigh tab. If you do not have past use information on a pasture, an alternate method for estimating production is the clip-and-weigh method. This tool walks you through the process of clipping and weighing random hoops to estimate production.

Animal performance should also be considered during planning for grazing. Nutrient levels vary over the growing season. During dormant stages some species nutrient levels may not meet the animal’s requirements. Ranch managers should become familiar with the nutrients in their forage species, how they vary over time, and what their livestock nutrient requirements are.

No matter what tool you use to estimate forage production and stocking rate, or if you use an online tool or the old pencil and paper method, it is important to include these estimates in a grazing plan. Even more important is to just take the time to think through and develop a written grazing plan. When we go through the process of writing a plan down, we often find things that we have previously overlooked or misjudged.

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