Pasture Management: Using Rotational Grazing

Published on Thu, 01/24/2019 - 11:46am

 Pasture Management: Using Rotational Grazing.

 By Bruce Derksen for American Dairymen Magazine.

 The use of rotational grazing, otherwise known as cell, mob, or holistically managed grazing has become accepted by only a moderate percentage of the agricultural community as an efficient and productive way to manage animal grazing.  The system can be extensively in the pasture manager’s control, but a 2012 Census of Agriculture found that only 30% of producers employed it which is down significantly from the previous 2007 Census.  Perhaps it has been a harder sell to the average operation as it undeniably costs both time and money, although in the long run, it can end up saving producers both.

In general terms, a rotational grazing system includes grazing, rest, animal impact and stock density modules.  Each of these pieces interact and influence one another in a positive or negative manner, with all parts being dependent on environmental conditions.
The grazing module sounds simple, but its time calculation is based on numerous factors including moisture, amount, type and quality of grass available along with number of animals.  In basic terms, the goal of the grazing module is to deliver a consistent forage to the cattle while keeping an eye on the other three aspects of the rotational grazing system.  In perfect conditions, animals should never take a second bite of the same plant during the same period.  A study by South Dakota State University claims rotational grazing increases long term profits and improves soil conditions with well managed grazing programs increasing quality forage production by 30- 70% each year.
The rest period of the pasture land is the time needed for plants to recover and re-grow.  For enough recovery, plants should reach late stage 2 production and transfer energy to their roots.  Re-growth is not only extra ingestible dry matter but should allow for larger leaf growth and increased surface area.  A grazed blade of grass has a minimal “solar panel” while blades that reach a length of 2 inches or longer have a much greater area for photosynthesis.  They will not only grow faster but recover quicker and produce larger amounts of forage over the course of the season.
Animal impact refers to soil compaction and stimulation which can decrease fertility and water absorption if not managed properly.  This module is directly related to stocking density and rates.  A benefit of proper animal impact management is soil can leverage an increased resistance to drought by retention of organic matter and forage cover.  Run-off from heavy rainfalls is slowed and soil will absorb available moisture more efficiently, in turn increasing forage production and maintaining growth for longer periods during drought conditions.

The stocking density module pertains to how tightly grouped the animals are in the paddocks or cells.  Proper density rates will deter selective over-grazing of the most palatable plants and help control less desirable forage and weeds.  Over time this will increase the amount of regular, consistent high-quality energy dense forage.
Beyond the direct benefits provided by the four aspects of rotational grazing, other random values include improved animal management and medical assessment.  Regularly moved cattle exhibit lower stress and are easier to manage. In favorable conditions, extra grass can be baled and fed at a later time.
Rotational grazing comes with financial cost 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 moving forward, attempt to keep the system as simple as possible.  Utilize 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.  
Environmental and weather conditions are the main factor dictating the number of paddocks or cells required and each operation will need to assess their own parameters in making these decisions.  While commodity pricing is beyond the producer’s control, cost of production is not.  Home grown feed has always been the cheapest feed source and boosted by natural waste as fertilizer, rotational grazing will solidify this fact.  With forward thinking, this will allow more stock per acre producing more net profit, thereby potentially encouraging a larger percentage of producers to participate in this environmentally friendly process.