For release: Aug. 13, 2003
Contact: Barry Dunn, (605) 688-5455

Stocking Rate Critical in Good Grazing Management

 BROOKINGS, S.D. -- Ranchers may have to adjust their assumptions about traditional concepts such as "stocking rate" and "animal unit" to make the best use of ranch resources, a specialist said.

Barry Dunn, range livestock production specialist for South Dakota State University Cooperative Extension, said stocking rate will be an important topic at the upcoming South Dakota Grazing School, “Managed Grazing – Pathway to Profit.” The grazing school takes place Sept. 9-11 at the CLC Ranch overlooking the Missouri River and at Al's Oasis in Oacoma. The registration deadline is Aug. 26. Contact Dunn for more information at (605) 688-5455.

"Stocking rate" is defined by the Society for Range Management as “the amount of land allocated to each animal unit for the grazable period of the year,” Dunn said. An animal unit is defined as “a 1000-pound cow with a calf up to 6 months of age.” “Carrying capacity” refers to the maximum stocking rate possible year after year without causing damage to the resources base.

But Dunn added that the traditional definitions no longer reflect reality in places such as South Dakota. That could have a rancher overstocking his range even if he's careful to go by the book, making it all the more difficult to manage through drought years.

Here are some points Dunn suggested for ranchers to think about:
* A cow no longer corresponds to an animal unit -- it's typically larger. "It would be hard to find a herd of cows in the Dakotas or Nebraska that weigh on average 1,000 pounds," Dunn said. Cows in many production systems are weighing between 1,300-1,400 pounds," Dunn said.

Cows eat 2-3 percent of their weight each day as dry matter. So the larger the animal, the more it eats.
"The cow that stocks most of our rangelands is consuming one-third more dry matter each day than the animal represented in the standard definition of an animal unit," Dunn said. "If we have increased the amount of forage removed by one-third, then we have also increased our real stocking rate by that much as well."

* A calf is not always a newborn. A calf at six months of age will also eat 2 percent of its weight as dry matter. A 500-pound calf is eating at least 10 pounds of forage a day. A cow with a calf at 6 months is not the same as a cow with a newborn.

* The facts about cow-calf pairs turned out on range have changed. A two-year survey of 485 South Dakota ranches taken in the late 1970’s found that on average, ranchers started calving April 27. In a survey of 185 cow-calf operations in the late 1990s, SDSU researchers found that the ranchers were beginning calving on March 1. "In the 1990s, cows turned to grass had calves almost 60 days older than just twenty years previous," Dunn said.

The yearlings are gone. Ranchers talk about how the financial crisis of the 1980s drove the yearlings out of cattle operations as they searched for liquid assets to right their financial positions and cut interest payments.

"I distinctly remember mutable ranches selling two-year olds for the last time in the mid 1980s," Dunn said. "Several classes of cattle and the flexibility that they brought to ranches disappeared." A ranch with a base level of 30 percent of its carrying capacity as yearlings probably is better able to respond to cyclical periods of above and below average precipitation, Dunn said.

"I would suggest that it is time to re-evaluate how simple things like “animal unit”, “stocking rate”, and “carrying capacity” are used in short- and long-term ranch planning," Dunn said.
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Lance Nixon, Editor
AgBio Communications Unit
South Dakota State University
ACC, Box 2231, Rm 200
Brookings SD 57007
Telephone: (605) 688-4653
LANCE_NIXON@SDSTATE.EDU