Rotational grazing is a proven concept. But it has become accepted by only a moderate percentage of the agricultural community as an efficient and productive way to manage animal grazing. A 2017 Census of Agriculture shows the number of operations employing such a system has actually decreased by more than 23,000 from 2012, adding to an even larger reduction of 100,000 from the 2007 Census results.
There is no doubt that rotational grazing comes with financial output, especially early in the process. Fencing materials and labor costs, along with potential water availability and expansions, are legitimate concerns and need to be evaluated. If considering such a system, attempt to keep it as simple as possible by utilizing existing farm fences, roads and lanes for easier cattle control and movement. Using temporary electric fencing during the first season will help to establish what works best so permanent fences can be added later in an effective way.
In general terms a rotational grazing system includes grazing, animal-impact, stock-density and rest modules. Each of those pieces interact and influence one another in a positive or negative manner, with all parts being dependent on environmental conditions.
Grazing module – The goal of the grazing module is to deliver consistent forage to the cattle while keeping an eye on the other three aspects of the rotational grazing system. That sounds simple but its time calculation is based on numerous factors – including moisture, type and quality of grass available, and the number of animals. When perfect conditions align, cattle should never take a second bite of the same plant during the same period.
Comparing continuous and rotational grazing programs, Dennis Hancock, University of Georgia-Extension forage specialist, said, “Of every 100 pounds of forage produced, only 30 to 40 pounds actually get into an animal. A slow rotation through three to four paddocks gets that up to about 60 percent.”
Animal-impact module – The animal-impact module is directly related to the stocking-density module. It refers to soil compaction that can decrease fertility and water absorption. Soil when properly managed can leverage an increased resistance to drought by retention of organic matter and forage cover.
Tong Wang is a production specialist with South Dakota State University-Extension. He cites the results of a survey pertaining to drought resistance completed by 315 South Dakota ranchers.
“Nearly 50 percent of the users perceived significant benefit of rotational grazing when it came to the increased resilience of grassland to drought,” he said.
Stocking-density module – The stocking-density module pertains to how tightly grouped the animals are in the paddocks or cells.
“What we want is higher overall stocking rates,” Hancock said. “At least 12 places I know of have looked at this; rotational grazing gives at least a 30 percent increase in stocking rate. Weeds are opportunistic. In the absence of competition they flourish. When you do things to encourage vigorous growth of desirable forages, weeds may disappear.”
Rest module – Like the straight-forward grazing period, the rest module should allow plants to reach late-stage-two production to transfer energy to their roots. Re-growth is not only extra ingestible dry matter, but is also an increase in existing leaf-surface area. “In a rotation program, with more biomass left after a grazing cycle photosynthesis continues at a higher rate,” Hancock said. “Plant vigor is enhanced.”
Environmental conditions are the main factor dictating each operation’s decision to employ a rotational-grazing system. While commodity pricing is beyond a producer’s control, cost of production is not. Optimal use of well-managed modules will maximize the potential of the varying plant life. They will boost the distribution of natural waste, allowing more stock per acre. That in turn will produce more net profit, encouraging a larger percentage of producers to participate in the environmentally friendly process.