Corporations use the term “right-sizing” as a kinder, gentler way of saying “layoffs.” The concept has merit though, as companies need just enough people to handle the workload and maintain quality while maximizing profits.
In a cattle operation, right-sizing can apply to the number of cattle turned out to a pasture or maintained on the ranch at a particular time. Too many animals result in overgrazing and potential long-term damage and lost productivity. Too few can result in opportunity costs due to under-utilization of forage. “Just-right” stocking rates optimize forage utilization for sustainability and profitability.
That “just-right” stocking rate, however, is a moving target for any particular ranch, with precipitation causing most of the movement. Ranches in some areas approach this spring in the grips of a multi-year drought. Others are emerging from drought and some others could be seeing early signs of drought settling in.
While most droughts are relatively short-term events, how a rancher responds can influence the long-term impact on the ranch and its forage resource. University of Nebraska range-management specialist Jerry Volesky, PhD, notes that fluctuations in precipitation can dramatically influence forage production on a ranch. Data from the university’s Barta Brothers Ranch in the east-central Sandhills show upland range annual production ranging from 880 pounds per acre in 2002 — a moderate drought year — to as much as 2,360 pounds per acre during 2009, a year with above average spring and early summer rainfall.
Clearly the ideal stocking rates during those years would have been significantly different, but stocking rates often are based more on averages rather than actual forage production. Volesky says 12 years of data from the same location show that annual forage production averages 1,770 pounds per acre, which would support a stocking rate of about 0.75 animal-unit months per acre. Most years though, the actual production is well below or above the average. The best stocking rate based on actual production would have ranged from a low of 0.37 AUM in 2002 to 1.11 AUM in 2009.
Volesky cites another study on mixed-grass prairie in eastern Wyoming where forage production ranged from 100 pounds per acre in a drought year to over 2,000 pounds per acre in a wet year.
Timing of precipitation also plays an important role in forage production, with the ideal timing depending on the location, soil type and mix of plant species on the ranch. Knowledge of these key times, coupled with precipitation records, can help ranchers make stocking decisions early to avoid overgrazing. In the Nebraska Sandhills where warm-season grasses dominate, for example, Volesky says precipitation during May, June and July correlate best with seasonal forage production. In mixed-grass environments in western South Dakota, research shows that April, May and June precipitation is the best predictor of production.
Enduring today’s drought
Texas Extension state forage specialist Larry Redmon, PhD, stresses that ranchers in areas currently affected by drought need to be stocked accordingly, and in some parts of Texas and the Southern Plains that means running no cattle at all. In these areas hit hardest by drought, ranchers need to think in the long term and delay re-stocking until pastures fully recover, he says. He reminds producers that even if they are feeding hay in pastures, cattle continue to graze and cause damage to drought-stricken plants.
Make decisions based on current conditions and long-range weather forecasts, Redmon says. The science and technology behind long-range forecasting has improved considerably in recent years. Current forecasts suggest the drought-stricken areas in Texas, New Mexico, Oklahoma and Georgia will remain dry at least through this year. So unless they see dramatic improvement in moisture levels and spring green-up, Redmon says producers in areas affected by the current drought should sit tight with their stocking levels or reduce numbers further.
Volesky agrees, saying that depending on the severity of drought last year, pastures might need longer recovery periods. In areas where moisture seems to be returning following moderate drought , producers should remain conservative in their stocking rates. Even as they recover, forage plants probably have less root growth and energy reserves, making them more susceptible to damage from overgrazing. In places affected by drought last year, or showing signs of drought this spring, consider delaying turnout for a couple of weeks to allow forages a little more time to develop.
Most pasture grasses are resilient, he says, and will bounce back fairly quickly when rains return. But in areas stricken with sustained extreme or exceptional drought, some death loss probably occurred in pasture grasses, meaning that even with good moisture it could take several seasons for plants to re-seed or spread into bare areas.
Respond early
Where drought appears to be emerging, Redmon encourages ranchers to begin de-stocking earlier rather than later. If you receive 75 percent or less of average precipitation for more than one month, it is time to consider reducing stocking rates.
Waiting too long can result in an environmental and economic disaster, Redmon says. Overgrazing reduces the ability of forage plants to produce energy through photosynthesis, reducing root growth and their ability to withstand and recover from drought. Loss of plant cover reduces the pasture’s ability to trap moisture, and runoff from bare ground results in lost topsoil, lost nutrients and pathogens possibly entering waterways.
Economically, Redmon says, ranchers who wait too long to de-stock can end up selling their cattle at a time when everyone in the area is liquidating their herds, resulting in a severely depressed market.
Volesky notes that drought affects the nutritional value of forage as well as total production, with plants reaching maturity earlier in the season and declining in nutritional value more quickly. In the Sandhills region, for example, the average crude protein content of native range on June 7 is 12.3 percent. During the drought year of 2002, researchers measured CP levels averaging 12.7 percent on June 7. But by July 30, 2002, when CP averages 10.3 percent, CP had declined to 5.9 percent in response to dry conditions.
Total digestible nutrient content for the same area averages 69 percent for June 7 and 54 percent for October 14. During the drought year of 2002, TDN averaged 53 percent on June 7 and 48 percent on October 14.
If drought conditions begin to take hold during the season, Volesky suggests planning for options to reduce grazing pressure and nutritional stress in the cow herd. Early weaning is one good option, as it reduces nutrient requirements for cows as well as the forage calves would otherwise consume. For every day earlier ranchers move weaning dates, they save about 10 pounds of forage per calf, or about 40 percent of the daily requirements for cows. Returning cows to good body condition after weaning benefits fertility and calving rates.
In addition to early weaning, Volesky stresses keeping the cow inventory at least current with normal culling rates. If drought becomes significant, consider culling deeper and earlier, possibly selling cow-calf pairs early in the season.
He also suggests an option of supplementing distillers’ grains mixed with low-quality forages such as straw or mature grass hay. This can reduce their grazed forage intake and extend supplies of standing forages.
For operations with irrigated land that could be planted with alternative forages, Volesky points out warm-season forages such as sorghum, sudangrass or millet can be planted during late spring or summer for late summer or fall grazing. Producers can plant cool-season small grains such as winter wheat, oats or rye in late summer for fall and spring grazing. He notes that seed supplies for some of these crops are short, particularly sorghum, sudangrass and millet for which much of the U.S. seed production is in areas stricken with drought last year. Overall, Volesky encourages flexibility in stocking rates. Monitor precipitation levels carefully during the critical period for your region, and try not to be caught with pastures stocked too heavily if the spring rains don’t arrive.
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