Grass growth rates and forage types help set rotation plans and grazing-pressure thresholds.

April 23, 2020

4 Min Read
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"We all understand that a ranch has to be economically viable in the short term to have any opportunity to be economically viable in the long term," said Hugh Aljoe, director of producer relations for the Noble Research Institute in Ardmore, Okla. That’s why management needs to adapt quickly to uncontrollable changes like drought, he said. Recordkeeping and monitoring are key.

The basics. In planning for available forage, Aljoe contrasted carrying capacity with stocking rate.

Capacity is a measure of the forage supply or how much grass is being produced. Stocking rate is a measure of forage demand, or how much grass is being grazed, he said.

"Carrying capacity changes from year to year or season to season based on moisture and our pasture management," he explained. "The better we manage, the more opportunity we have for production."

Monitoring carrying capacity throughout the year helps determine where adjustments should be made to stocking rate. It’s a supply-and-demand relationship based on what the pasture produces and what the cattle need.

Across the country, rainfall varies in amount and timing, which affects growing patterns and pasture management, Aljoe said.

The first thing Aljoe looks at is historical annual precipitation. Start by studying rain at the end of the growing season in October, "when the water begins to recharge the soils," Aljoe advised.

By the end of March, there should already be 40% of the annual rainfall, he said. The amount of precipitation accumulated in the soil will determine whether it’s going to be an early or delayed spring.

"Did we receive abundant rainfall and can add more numbers? Or did we receive less rainfall and need to de-stock in order to preserve our pastures?" he asked.

Regardless of where a ranch is located, 30-35% of annual forage production should occur by the end of May. That increases to 65% by the end of June, when yearly rainfall should reach 65-75%, Aljoe said, referring to water table records.

"If we're not there in the spring, we're probably never going to catch up," he said, explaining that while livestock can have compensatory gain, "unfortunately pastures cannot."

Another important component is variance, or how much rainfall is normal, positive or negative. Small differences are less critical than those above 10-15 percentage points.

Aljoe shared one example of when forward-looking management saved the ranch. Charting a major drought as it developed in the spring, management at the typically 1,000-cow ranch sold more than 700 head before major downward price pressure. By September, those pastures stood out for not showing much drought stress.

"The land resource was maintained," Aljoe said. "That’s what is possible when you use the water table."

Look down. "Take half; leave half" is a good starting rule, but grass growth rate and forage type help set rotation plans and grazing-pressure thresholds, Aljoe said.

"In the South, there’s bermudagrass, or fescue in the North," Aljoe said. "Those we can take as much as 50% to 65% of the production every time we graze, because they'll recover rapidly. On the other hand, on native range pastures, we only want to take 25%, at best."

How often does a rancher walk across a pasture and look down? Is the ground cover highly unfavorable, unfavorable, favorable or highly favorable?

"You want to rate it on a system where there is no middle ground," Aljoe said. Even numbers make it easier to see if land needs improvement or maintaining.

Building small exclusion plots with wire panels and T-posts is another way to monitor the amount of forage grazed.

"We never want to take more than half," he said. "In the early growing seasons, we don’t want to take but the top third in a good grazing program."

Some producers like to make cattle "hustle," eating what’s probably better left as residual ground cover, Aljoe said. Forced "cleanup" grazing may damage the forage’s ability to come back and can leave soil unprotected. It can take years to recover.

Visual evidence. Sometimes, it’s hard to see the changes, so Aljoe suggested using visual evidence from the same "photo points" each year.

Take pictures at the peak and end of growing seasons, marking locations with a simple T-post or through a downloaded global positioning system (GPS) app.

"We had a producer that bought a degraded resource, and through management planning, he took it from poor condition to what we would consider excellent condition in just five years," he said, noting that the photos played a key role.

Doing something is better than doing nothing. Be consistent, and only make it as complicated as you’re willing to stand, he said.

It can be as simple as these examples or customized with free consultation from resources like the Oklahoma-based Noble Research Institute or the government’s Natural Resources Conservation Service.

A powerhouse cow can’t grow a calf of the same caliber without the grass to match.

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