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Rotational Grazing

What - Why - Where - How??

Sid Brantly, Grazing Lands SpecialistBy Sid Brantly, Grazing Lands Specialist, NRCS - Kentucky
This article was originally written for Hoofprint Magazine (The Small Ruminant Magazine - Spring 2013)

What is rotational grazing? 

Rotate What?
When these goats are rotated into a fresh, wooded pasture, they forage voraciously, reducing the grazing and browsing selectivity.

Rotational grazing is a management strategy used to maximize forage growth and encourage desirable plants and plant parts!  Generally, the leaves of plants are much more palatable, nutritious, and photosynthetically active than stems.  And, of course, some plants are much more nutritious than others.    In order to maximize forage growth, livestock are strategically moved through a series of fresh pastures in order to provide a “grazing-rest period” for plants to regrow their leaves; which in turn photosynthesize more plant tissue; which then grow at a faster rate because there is more leaf material.  After a period of significant regrowth, livestock are rotated back to the point of origin while plants are still leafy and have not begun building a lot of stem tissue.  Because livestock are more concentrated in the pasture (while other pastures are resting) the normal activity of “consuming only the most desirable plants and leaving the rest to dominate” is curtailed.

Continuous grazing (the alternative to rotational grazing) tends to result in the best forage plants being weakened by regular grazing, while the least desirable plants thrive.  This results in poor grazing efficiency because only part of the vegetation is utilized at its optimum rate.

Why implement rotational grazing?

More forage!   A multi-agency effort by the Natural Resources Conservation Service, the National Institute of Food and Agriculture, The Agricultural Research Service and the National Resources Inventory reviewed 27 research papers that included both rotational and continuous grazing systems.   Eighty-five percent of the research papers reported greater forage quantity resulting from the rotational grazing.  The average forage production advantage was thirty percent!   This increase in forage produced is then coupled with an increase in grazing efficiency.   Rotational grazing in small research paddocks generally increases utilization rates by five to fifteen percent over continuous grazing.  However, the actual improvement in utilization may be much more in larger-sized, production operations.                            

Why rotate?
With rotational grazing, a more nutritious "cocktail" of forage choices can be offered to livestock.  On this farm in Ohio, there is forage chicory, perennial ryegrass, orchard grass, tall fescue, clover and dandelion. 

More pasture plant diversity!   A better diet offered by a mixture of grasses, forbs, and woody species can improve sheep, goats, and cattle performance.  Providing appropriate “graze” and “rest” periods through rotational grazing, and stocking at or below the farm’s carrying capacity (not overgrazing) allows many of the preferred forages to recover between grazing cycles.   When leguminous forbs and/or woody species are not grazed out from continuous overgrazing, the plant community benefits from nitrogen that is “fixed” by the plants; and the animals benefit from the increased protein and digestibility of the legumes!

Superior persistence of desirable forage plants!   Rotational grazing allows the desirable plants to grow more “above ground” vegetation.  The chlorophyll in the additional leaf tissue produces additional roots for a healthier plant.  The more robust root system can, in turn, provide the water and nutrients from deeper in the soil profile, resulting in a more “drought-proofed” pasture.  In this way, the desirable plants can persist while the invading weeds cannot easily gain a foothold.

The tall fescue plant on the left was not grazed or clipped.  The plant in the center was clipped once per month at three inches height, simulating rotational grazing.  The plant on the right was clipped once per week at one inch height, simulating continuous overgrazing. Root growth related to grass height

 

Opportunities to extend the grazing season through stockpiling of forage!  Stockpiling is allowing forage to grow in order to use at a later date, or when pasture plants have stopped growing.  Almost any grass or leguminous forb can be stockpiled.  Tall fescue is often the “standard” for stockpiling because it grows well into the late fall and holds forage value well.  It is also important to note that the anti-quality alkaloid in the most-common “fungus-infected” strains of Tall fescue declines rapidly during late fall and winter.  Rotational grazing gives managers the opportunity to stockpile forage, which helps extend the grazing season and reduce feed purchases.

Grazing Goats
These goats have been turned into a wooded pasture that has been rested.  The animals will not be grazing/browsing primarily from "ground level."

Greater control of grazing and browsing heights!  Gastrointestinal parasite loading is highest near the ground.  The increased growth and performance of the plants result in higher sward heights for the grass, and increased woody understory recovery for browsing.  Goats will then be consuming forage at a higher level, thus ingesting less numbers of parasites.

Where do I implement rotational grazing?

Rotational grazing can be implemented wherever forages are grazed!  It can be used on farms with flocks of sheep, herds of goats, a brace of ducks, a herd of cattle, or even a flerd.  A flerd is a group of mixed livestock species (grammatically FLock-hERD contraction) in which the small ungulates (sheep, goats) are bonded to the larger ones (typically cattle) in such a way that they consistently remain together.  Rotational grazing with more than one species of livestock usually increases the efficiency of forage utilization and reduces the intensity of “landscape maintenance” practices such as mowing, chopping, or herbicide application.  This is because cattle have a higher level of preference for grass, goats for woody plants, and sheep for forbs.   Manipulating the percentages of different grazing animal species can also be used to change pasture composition to have more grass, more forbs, more woody plants, or any combination of these plant types. 

Left (before): Goats were used where the author wanted to change this weedy pasture and brushy woodland into a grass dominated silvopasture for use by beef cattle on right (after).
 Grazing in weedy pasture

Cattle getting water in field

 

How do I implement rotational grazing?

Begin by creating multiple pastures and grouping livestock into a flock, herd, or flerd that can be rotated from one pasture to the next so that you build “forage recovery periods” into your management.    Fortunately, technological advances in livestock water system design and fence materials have helped to create a feasible working environment where rotation livestock from one paddock to another can be both convenient and affordable. 

 Estimated Water Intake Table
(Source: D.M.Ball, C.S.Hoveland, and G.D.Lacefield)
Livestock Class Daily needs in gallons per Head at 50 degrees F Daily needs in gallons per Head at 90 degrees F
Sheep and Goats 1.5 3.5
Beef Cow 8 20
400 lb. Calf 4 10
Dairy Cow 15 30
Horses and Mules 8 12

The table (right) illustrates the wide range of water intake needed by different types of livestock.  Water use also varies considerably depending upon the animal’s health, air temperature, water temperature, stage of lactation, and additional environmental factors.  Traveling long distances to water can limit animal performance (the less they drink, the less they eat) and tends to promote overgrazing in areas closest to water and underutilization of forages located at greater distances.  Portable water systems using high-density polyethylene, freeze-resistant portable pipe and quick-connectors offer a “quick” solution to the problem of “water short” pastures.

Fencing is the second facilitating practice you will need to install in order to begin rotational grazing management.  Boundary fences for sheep or goats would normally be woven wire (with barbed wire top and bottom) or five to seven strand, high-tensile steel, electrified fence.  These should be constructed with the idea of containing all of the livestock classes (ewes, lambs, does, kids, bucks, rams, and/or cattle) that will be in the grazing system.   Properly designed and constructed boundary fences can also help deter many predators.  Keep in mind that most predators go under or through boundary fences as opposed to over them.  Interior cross-fences are typically three to four strand permanent electrified steel wire, polywire/polytape, or electric netting. 

Protecting livestock from predators usually presents itself as a challenge in a grazing management system, and is normally addressed with guardian dogs, donkeys, or llamas.  Each type of guardian has its own, unique set of issues to deal with and needs to be studied in depth before selecting  a guardian for your particular conditions.  Combining small ruminants and cattle into a flerd also conceives the need to consider the phrase “research before reliance.”   Sheep and cattle, goats and cattle, or sheep, goats and cattle haphazardly thrown together will not be bonded.  Bonding is a necessary part of flerd management, and needs to be done correctly in order to have a more “predator resistant” group of animals.  Animal observation and health is also necessary in order to implement successful grazing management.   Certainly gastrointestinal parasite management through “famacha” type diagnosis, culling highly-susceptible animals, judicial treatment, and managing grazing/browsing heights through rotational grazing and proper feeding techniques is an absolute necessity.

Using modern fencing technology for rotational grazing and applying systematic animal observation and health practices will go a long way towards a successful grazing/browsing operation.
Animal observation Rotational fencing

 

When the fences and water facilities are correctly installed, predator control issues are addressed, and the animal health planning is behind you; it’s time to begin rotational grazing!  Start by resting the best pastures first.  The best pastures will respond the fastest to a grazing deferment, giving you the most forage return for your time, labor, and investment.  When the flock, herd, or flerd has grazed the vegetation to the proper degree, move them to the next pasture.  The proper degree of grazing/browsing can be best assessed by local extension agents, natural resource conservationists, or other practitioners / professionals / researchers in your local area.  But as a rule of thumb, do not graze introduced grass plants (fescue, orchardgrass, bermudagrass, bahiagrass, dallisgrass) any shorter than 2-4 inches and do not graze native grass (big bluestem, indiangrass, switchgrass, gamagrass) any shorter than 8-10 inches, nor remove more than about 50% of the leaves and twigs of desirable woody species.  In fast-growing, introduced pastures, grazing periods should not exceed 3 to 7 days.  The concept here, is that plants should not be grazed twice during the same grazing period.  The rest periods should be 2 to 6 weeks, depending on how fast the vegetation is growing back.   As you rotate the flock/herd/flerd through the pastures, if the pasture ahead of the rotation is seeding out, then shorten the grazing periods in order to keep the pastures from becoming over-mature.  If the pasture ahead of the rotation has not recovered to some level above the proper degree of grazing, then lengthen the grazing periods in order to provide longer rest periods.  If this issue persists, then consider reducing the numbers in your flock/herd/flerd in order to match your forage requirements with the available forage.

There are some mistakes that can be made when beginning a rotational grazing.  However, there is far more to gain from the practice than there is to lose!   So, by all means….begin!