foraging behavior and grazing management planning

Pasture and Range ManagementJan. 2007

PRM-2

Published by the College of Tropical Agriculture and Human Resources (CTAHR) and issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperationwith the U.S. Department of Agriculture. Andrew G. Hashimoto, Director/Dean, Cooperative Extension Service/CTAHR, University of Hawai‘i at Mänoa, Honolulu, Hawai‘i 96822.An equal opportunity/affirmative action institution providing programs and services to the people of Hawai‘i without regard to race, sex, age, religion, color, national origin, ancestry, disability,marital status, arrest and court record, sexual orientation, or status as a covered veteran. CTAHR publications can be found on the Web site <http://www.ctahr.hawaii.edu/freepubs>.

Foraging Behavior andGrazing Management Planning

Mark S. Thorne1, Glen K. Fukumoto2, and Matthew H. Stevenson1

Department of Human Nutrition, Food and Animal Sciences1Kamuela and 2Kona Extension Offices, UH-CTAHR Cooperative Extension Service

Asuccessful grazing management plan requires asound understanding of the effect the grazing

animal exerts on the range or pasture ecosystem. Thegrazing animal exerts pressure on the range or pastureecosystem through consumption and trampling of theplants, by their digestive processes, and by their move-ment across the landscape. Separation of this total in-fluence into individual factors (Heady and Child 1994)increases understanding of the grazing impacts and pro-motes informed grazing management decisions. Man-agers who learn to manipulate the grazing factors listedin Figure 1 are typically the most successful at main-taining forage and animal production goals.

The goals and objectives of a successful range or pas-ture management plan are achieved only through twodistinct methods of manipulation of the vegetative com-munity: (1) by altering the grazing factors or (2) throughrange improvement practices. Range improvement prac-tices include applications of seeds, fertilizers, or otherimprovements directly to the soil-vegetation complex.While these practices can be an important and effectivetool for land managers, they are usually costly. For thisreason they are usually reserved for drastically disturbedrangelands and pasturelands, where recovery from deg-radation would otherwise be too slow.

Four grazing factorsA grazing animal selects for certain plants or plant partsand consumes them to a particular degree, resulting in acertain grazing intensity. This grazing event occurs dur-ing a specific season in the growth of the plant and may

be repeated. Each of these four factors—selectivity,intensity, season, and frequency (repeated grazing)—influences the growth and reproduction of the grazedplants differently. Inherently then, plant communities areinfluenced differently. Thus management of the animalscan influence the vegetation of range and pasture sys-tems by manipulating their relationship to the four graz-ing factors (Figure 1).

It is important to understand, however, that one graz-ing factor does not occur without the others. Grazinganimals exert the various grazing impacts at the sametime (Figure 2). For example, a cow tramples plantswhile grazing forages to a definite degree or intensityduring a specific season (or period of growth for theplant). Thus, the grazing process and the resulting plantresponse is a dynamic interaction dependent on the com-position of the plant community and the species of ani-mal (which determines animal behavior).

Successful livestock managers generally have a goodunderstanding of the dynamics of interaction betweengrazing animals and the plants that support them. Whilethe response of the plant community to grazing is im-portant to a grazing management plan, it is not the focusof this publication. Instead, we provide an overview ofthe factors that influence foraging behavior and showhow it needs to be considered in the development of asuccessful grazing management plan.

Foraging behaviorDifferent kinds (species) and classes (heifer, steer, lac-tating, growing, etc.) of grazing animals utilize range

UH–CTAHR Foraging Behavior and Grazing Management Planning PRM-2 — Jan. 2007

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Figure 1. A conceptual representation of the relationship between the land, animals, and vegetation (adapted fromHeady and Child 1994).

and pasture systems differently (Figure 3). Specifically,the foraging behavior of a given kind or class of animaldetermines how it moves across the landscape and se-lects different forages. In the process of grazing, an ani-mal progresses through levels of instinctive responsesand behaviors that lead to the consumption of a plant(Stuth 1991). These instinctive responses and behaviorsare driven by sensory cues and the physiological needsof the animal. These vary across the landscape andthrough time.

Factors that influence foraging behavior can be di-vided into two categories: factors that affect spatialchoice, and factors that affect forage species choice.Spatial choice is a function of landscape features, plantcommunity characteristics, and grazing patch attributes.

Landscape featuresForaging behavior at the landscape level is primarily afunction of physical and thermal features of the rangeor pasture system that influence animal distribution and

Managed grazing animal

Animal nutrient requirementsSpecies of animal

Breed typeKind / class of animal

Range or pasture ecosystem components

Vegetative community Landscape conditions Abiotic conditionsSpecies composition, distribution Configuration ClimateGrowing season Accessibility SoilsEcological condition Water TopographyTrend Size, terrain

Grazing factors

Intensity of grazingSeason of grazing

Frequency of grazingSelectivity

Animal behavior

Mineral cyclingPhysical

environment

Resources

redistributed

PlantsMinerals

Other

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movement (Table 1). The ar-ray of certain features acrossthe landscape influences howthe grazing animal will uti-lize the range or pasture sys-tem as they seek to meetphysiological needs. Physi-ological needs of grazing ani-mals that determine distribu-tion and movement across thelandscape include, in order ofimportance to the animal:1. thirst2. heat/cold

(thermal balance)3. hunger4. orientation and

predator avoidance5. rest.

The grazing animal mustmaintain water balance ordie. Thus thirst is the most in-fluential physiological needdetermining animal move-ment and distribution acrossthe landscape. Stuth (1991)defines large ungulates as“central place foragers.”That is, they have a homerange that is centered on wa-ter. Cattle and sheep gener-ally do not graze beyond 1mile from water. Conse-quently, a distance betweenwater sources of greater than2 miles reduces grazing ca-pacity by 50 percent. Whencalculating stocking rates inlarge pastures, managersmust consider not only thespatial distribution of theherd in relation to all thewater sources but also the frequency of drought. Stock-ing rates will need to be adjusted accordingly.

Maintaining a neutral thermal balance is a majorphysiological requirement for grazing animals and of-

ten takes precedence over alleviating hunger, especiallywhen they are experiencing temperature extremes. Land-scape features that provide relief from temperature ex-tremes include trees for shade and riparian areas or

Figure 2. Young steers grazing a pasture on Maui. The animals simultaneously selectparticular plants and plant parts as they graze.

Figure 3. Cattle and goats share a pasture on an up-country Maui ranch. The cattlegraze primarily on the grasses in the pasture, while the goats browse on the shrubsand forbs.


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gulches that provide protection from the wind. Animalthriftiness often suffers in areas where relief from tem-perature extremes is not available.

The final three physiological needs of the grazinganimal are interrelated: mitigation of hunger (maintain-ing energy balance), orientation and predator avoidance,and rest. After grazing for some time, most ungulatesmove to loafing or bedding areas to ruminate and digestfood. This will be in an area where the animal feels safefrom predators or other threats. Animals generally grazefirst near their water and shelter areas and then moveoutward. The distance traveled while grazing is a func-tion of their digestive (gut) capacity, potential harvestrate of forages encountered, grazing velocity, and level

of hunger. These grazing patterns often produce ringsof diminishing levels of forage utilization as distancefrom the water source or bedding ground increases.

Plant community characteristicsA plant community is typically defined by its structuralconfiguration, spatial arrangement, and plant species com-position. Plant communities can be further divided intopatches of more uniform groupings of species. The distri-bution of these patches influences the foraging behaviorof the grazing animal within the plant community. Selec-tion of a particular plant community by a grazing animalis largely a function of the site attributes that determinethe animal’s ability to harvest nutrients (Table 2).

When considered in relation to grazing by livestock,plant communities can be divided into four categories(Stuth 1991): grazing-preferred, grazing-avoided, ter-rain-constrained (directed-use), and high-impact (Fig-ure 4). The bulk of the grazing animals’ forage is de-rived from grazing-preferred sites, which have highoccupancy-to-area ratios and high utilization-to-forage-mass ratios. Grazing-preferred sites typically have agreater density of high-quality forage species. This of-ten results in slower grazing velocity and greater resi-dence time relative to other grazing areas available tothe animal. For these reasons, grazing-preferred sites caneasily become overgrazed when management actions arenot timely.

Grazing-avoided areas generally have low foragevalue, either because of the plant species composition

Table 1. Characteristics of the landscape that affect thedistribution, movement, and diet selection of grazinganimals.

Attribute Components

Boundaries Fences, home range, migration routes

Distribution of Range sites, soils, aspect, elevation, plant communities structure, species composition

Accessibility Slope, gullies, streams, shrub density,rockiness, roads, trails, fence lines,cut openings

Distribution of Location of water, shade, loafing and important features bedding sites, and other convergent

and divergent points in a landscape

From Stuth, 1991

Table 2. Attributes at the plant community and area level that influence the animal’s selection of forage sites.

Attribute Function affects

Soil moisture-holding capacity Forage supply and stability

Species composition Suitability/stability of the site to meet general nutritional needs

Plant frequency Probability that the animal will encounter a desirable plant species;number of dietary decisions the animal makes

Abundance Supply of nutrients

Structure Accessibility of forages species

Continuity Animal movement rate

Size Amount of search area available

Aspect Thermal characteristics of the site

Orientation in the landscape Frequency of exposure to grazing (position relative to other areasthat meet animals needs)

From Stuth, 1991

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Figure 4. Grazing-preferred areas (A) provide the bulk of theforage consumed by the grazing animals. Grazing-avoidedareas (B) typically have low forage value, either because ofspecies composition or inaccessibility. High-impact grazingsites (C), sometimes referred to as “sacrifice areas,” occuraround water sources and along trails.

A

B

C

or because they are not readily accessible. Terrain-constrained (directed-use) sites generally have longoccupancy time but low utilization levels, often de-spite abundant forage. These sites typically resultfrom concentration of the herd in pasture cornersor against gullies, hills, or roads. Finally, high-impact grazing sites have low residence times rela-tive to the area but have high utilization levels.High-impact sites develop along directional graz-ing paths such as trails to water and shelter areas.

Foraging behavior and grazingmanagementThe primary focus of a grazing management planis to properly distribute the grazing impact acrossthe pasture. By doing this, managers increase thequantity and quality of the forage available to thegrazing animal and allow adequate recovery timefor the forages between grazing events.

Poor grazing distribution within pastures has beenand continues to be a major problem confronting live-stock managers. On most range and pasture systems,improvement will occur without reducing livestocknumbers if practices that provide more uniform graz-ing are implemented. Determining the appropriatepractices to implement takes a thorough apprecia-tion for the interaction between an animal’s forag-ing behavior and factors that contribute to poor graz-ing distribution. Holechek et al. (1989) listed the fac-tors that lead to poor grazing distribution, which aredistance to water, rugged topography, diverse veg-etation, wrong type of livestock, pests, and weather.

Improving animal distributionSeveral factors can be used to improve livestockdistribution in Hawai‘i, including• changing and/or increasing the number of

water sources• increasing the number of and/or changing salt,

mineral, and supplemental feed stations• fencing• changing the kind, class, or breed of grazing

animal• changing the grazing system• range improvements• construction of artificial features to provide

shade or protection from wind.


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Water. Poor distribution of water within the pasture isthe primary cause of poor livestock distribution in mostgrazing systems. Grazing utilization tends to be highestnear water sources and decreases with distance from wa-ter, resulting in zones of over-utilization nearby water andunder-utilized pasture farther away. There is usually moreunder-utilized area in a pasture than over-utilized area.

Recommendations on distance between wateringpoints depend on terrain, type of animal, and breed oflivestock. Generally, distances should not exceed 0.5mile in rough country, 1 mile in rolling or hilly country,and 2 miles in flat country. Also, the capacity of the watersystem (storage volume and recharge rate) must be ad-equate for the number of animals. Inadequate supply ofwater will lead to poor animal performance as they com-pete for water. For large pastures, a common rule ofthumb is to provide one watering point for every 50 headof cattle or 300 sheep. This helps maintain animal con-dition and provides good grazing distribution across thepasture. In small, intensively grazed pastures, these ra-tios can be doubled.

Often the development of additional watering pointswill improve livestock distribution and productivity. Newwater sources can be developed by drilling wells, in-stalling pumping units, constructing storage tanks anddrinking troughs, constructing catchment reservoirs, andpiping water to new locations. Each manager will needto determine what type of water development is mostfeasible economically. Managers should carefully selectthe location, number, and distribution of new wateringpoints relative to existing ones within their pastures toimprove animal distribution.

Salt, mineral, and supplemental feed stations. Care-ful placement of salt, mineral, and other supplementscan be a great tool to obtain the desired distribution ofgrazing animals and can increase grazing capacity by asmuch as 20 percent. Livestock usually go from water tograzing and then to salt. Thus it is not necessary or de-sirable to place salt near watering points. In fact, strate-gically placing salt in grazing-avoided areas is one meansto entice livestock to use these areas. Desirable areasfor salt grounds include ridges, knolls, benches, andgentle slopes away from water. In large pastures, saltshould be placed at the farthest distance between water-ing points (0.5–1 mile).

Fencing. Fencing is typically used to divide largerange units into smaller units. In planning fence place-

ment, the livestock manager should carefully considerthe location, size, and shape of the grazing units as wellas the direction of livestock rotation. Fences serve to(1) control the movements of livestock, (2) regulate useamong forage types or protect choice grazing areas forspecial use, and (3) separate range or pasture units forspecial management.

Uniform grazing is difficult when several vegetationtypes (or range sites) occur in the same grazing unit.Separating large grazing units into several smaller unitsthat are more or less similar greatly increases the uni-formity of grazing. Utilization of less palatable foragespecies can be greatly increased by increasing the den-sity of livestock on each unit for short periods.

Kind, class, and breed of grazing animal. Livestocktypically fall into one of three groups based on their pref-erences for different forage types. These groups includegrazers (cattle and horses) whose diet is dominated bygrasses, browsers (goats) who graze primarily on forbsand shrubs, and intermediate feeders (sheep) who ex-hibit no particular preferences among grasses, forbs, orshrubs. Understanding these grazing preferences canhelp managers match the type of livestock to their rangeor pasture system. Moreover, multi-species grazing sys-tems can be an effective management tool to controlundesirable vegetation. For example, goats can be usedto reduce cover of undesirable shrubs and encouragebetter production of grasses for cattle production.

Within a species, different types of animals use therangeland or pasture system differently. For example,yearling cattle will use rugged terrain better and willrange farther away from water than cows with calves.Likewise, some breeds of cattle will make better use ofrough terrain than other breeds, and still others are moresuited to dry country than others. Selection of the properbreed and type of cattle for your operation can be, there-fore, an important decision.

Grazing systems. There are many different types ofgrazing system, and a full discussion of all the varia-tions is beyond the scope of this publication. Discus-sion here is limited to a brief description of the differentsystems typically used and conditions where they aremost effective.

Factors that need to be carefully considered whenselecting a grazing system include climate, topography,vegetation, kind or class of livestock, wildlife needs,watershed protection, labor requirements, and fencing

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and water developmentcosts. Each type of grazingsystem carries with it a dif-ferent set of costs for devel-opment and maintenance.Likewise, each system re-quires a different level of la-bor input. Finally, there is noone system that is best in allsituations.

Continuous grazing (con-tinuous stocking, or setstock). A continuous grazingsystem is one in which thepasture is continually stockedwith livestock. It is widelyspeculated that this type ofgrazing program results inovergrazing of desirablegrasses, but this is not sup-ported in the literature(Holechek et al. 1989). Theadvantage of continuousgrazing over other systems is also part of the problem.Under good management, continuous grazing allows theanimals to select the most nutritious diet over the great-est period of time. Thus, their production relative to ani-mals in other systems may be higher. However, this se-lectivity is typically problematic over the long term andoften results in areas of overgrazing (preferred-use ar-eas). These are in areas where forage, water, and coverare in close proximity (Figure 5). This type of grazingsystem is most suited to areas where landscape featuresand the vegetation type, quantity, and quality are rela-tively uniform over large expanses. For example, thisgrazing system is typically used in dry desert environ-ments where forage production is very low, such as westTexas. In this type of system, pastures need to be largeand stock density needs to be very low to avoid over-utilization of grazing preferred areas. Very few areas inHawai‘i are suited to continuous grazing; most of theseare located in the leeward ranges of the island of Hawai‘i.

Deferred rotation. This system involves using mul-tiple pastures (usually two, but sometimes more) thatare periodically or seasonally deferred from grazing(ungrazed for a particular season of year) on a rotationalbasis. The period between deferments for a given pas-

Figure 5. An example of a continuously grazed pasture along the Hämäkua coastshowing signs of overgrazing: severe erosion, encroachment of weeds, and low vigorof desirable forages, resulting from long-term, chronic overgrazing with a stock densitythat is too high.

ture varies depending on the total number of pastures inthe system. This system provides a better opportunityfor preferred plants to maintain vigor than does con-tinuous grazing. Typically this system is best suited tolarge operations with pastures having different seasonsof production or different forage types. For example, adeferred-rotation system would work well for largeranches in Hawai‘i that have high-elevation kikuyugrasspastures and low-elevation guineagrass pastures.

Rest rotation. This system incorporates a 12-monthrest period for one pasture while the remaining pasturesabsorb the grazing pressure. However, the benefits fromthe year-long rest on one pasture may be lost to the ex-tra use that occurs in the grazed pastures. Pastures arealternately rested in successive years. This system is bestsuited for medium to large operations that have rela-tively uniform forage type, production, and quality acrossall pastures. Annual stocking rates need to be estimatedbased on the pastures being utilized for any given year.

High-intensity–low-frequency (HILF). This systemof rotation grazing typically involves three or more pas-tures, with grazing periods longer than two weeks andperiods of non-use extending beyond 60 days. An im-portant feature of this grazing system is that it forces the


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livestock to use all of theavailable forages in the pas-ture more uniformly. This re-duces the competition be-tween palatable and less pal-atable forage species andprevents undesirable shifts inspecies composition. The ex-tended periods of non-useare intended to offset theheavy use levels that occurduring grazing.

Animal performance un-der HILF grazing is reducedcompared to animals on con-tinuous grazing programsbecause their average diet isof lower quality. However,under the right conditionsHILF can result in a highercarrying capacity, perhapsoffsetting the loss in averageanimal performance. TheHILF grazing system worksbest in flat, humid rangelands such as in the tropical andsubtropical ranges in Hawai‘i where recovery from graz-ing is rapid (Figure 6). HILF is not a suitable grazingsystem for rugged, arid rangelands such as are found onthe leeward sides of Hawai‘i and Maui.

Short-duration (SD, SD–high intensity, cell grazing).Short-duration grazing systems typically involve mul-tiple pastures arranged in a wagon-wheel pattern withwater and livestock handling facilities located in thecenter of the wheel. However, SD grazing can be ap-plied without the use of the wheel arrangement, whichis now discouraged because of the large impact causedby concentrating animals continuously in the center.

Ideally, the grazing period for each paddock is short(five days or less) followed by four to six weeks of non-use. Typically, livestock are moved more quickly dur-ing active growth periods than during slow growth ordormant periods. The high stock density (numbers ofanimals per unit area) is thought to• improve water infiltration through animal hoof

action• increase mineral cycling• reduce animal selectivity

• improve forage plant leaf area index• give more even use of the range or pasture system• increase the availability of green forage• reduce the percentage of ungrazed plants.

Like HILF grazing, SD grazing works best in flat,humid regions with extended periods of plant growth. Itis successfully utilized in Hawai‘i on windward and low-to mid-elevation ranges. It is not suitable for windy, rug-ged ranges on the leeward slopes of the islands.

Range improvementsSeveral techniques can be used to improve range or pas-ture condition, including fertilizer application, prescribedburning, mowing, inter-seeding with more desirable for-age species, and irrigation. Often the additional cost as-sociated with the implementation of one or more rangeimprovement practice is offset by the increased grazingcapacity of the range or pasture system. While the pri-mary focus of implementing most range improvementpractices is to increase the quality and quantity of for-ages available in the pasture, another equally importantoutcome is improved animal distribution.

Figure 6. An example of a well managed high-intensity–low-frequency (HILF) grazingsystem in Hawai‘i. Note the different degrees of pasture growth. Dark green pastureshave fully recovered and are ready to graze, brown pastures have recently been takenout of grazing, the light green pasture at right has been out of grazing for a couple ofweeks, and the pasture with the cattle is nearing full utilization.

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Figure 7. Light applications of lime (2.5 tons/acre CaCO3) and nitrogen (69 lb/acre N)effectively increase forage quantity and quality in pastures converted from formersugarcane and pineapple lands. Note the difference in plant vigor between the treatedplot (application of N and CaCO3) on the right and the untreated plot on the left threemonths after treatment.

The use of fertilizers to in-crease production andachieve a better animal dis-tribution on range and pas-ture systems is well docu-mented for most temperatesystems (see Herbel 1963,Graves and McMurphy 1969,and Wight and Black 1979).Amendments also enhancethe mineral cycling in therange or pasture ecosystem.In Hawai‘i, the addition ofsmall amounts of agricul-tural lime (CaCO

3; 2.5 tons/

acre) and nitrogen (69 lb/acre) are very effective inincreasing production of de-sirable forages on formersugarcane and pineapplelands (Figure 7). Strategicapplications of soil amend-ments can be used to drawanimals into areas that oth-erwise receive little or no use.

Prescribed burning is an effective tool to reduce oldgrowth, burn out weedy species, and improve grazingdistribution. The accumulation of litter in excess of 1600lb/acre can cause a reduction in bacterial activity neces-sary for sustaining decomposition of organic matter inthe soil due to reduced soil temperatures. Althoughslowed, the breakdown of that litter also ties up nutri-ents in the system so that they are unavailable for plantgrowth. Finally, a heavy accumulation of litter slowsthe cycling of nitrogen within the system. Burn prescrip-tions can be developed to remove litter build-up and,with proper time for recovery, increase the quality andquantity of forages in areas previously under-utilized.While the judicious use of fire has been shown to beeffective in many regions of the world, it is not com-monly used in Hawai‘i. However, prescribed burning inHawai‘i has a great potential to be an important tool formanagers interested in controlling many kinds of inva-sive species and improving pasture condition.

Mowing is commonly used in Hawai‘i to remove old,poor quality forage in guineagrass pastures. While thismethod helps managers maintain the quality of these

pastures, the cost of equipment, maintenance (parts),fuel, and man-hours makes it one of the most expensiverange-improvement techniques. It is most beneficialwhere stocking rates are insufficient to keep up with therapid growth of the forages. Mowing can also be effec-tively employed to reduce the cover of undesirableshrubs and weeds.

Where mowing is used, the period between mowingand grazing needs to be long enough that forage vigorrecovers. The grazing capacity of a mowed pastureshould be based on the amount of new growth avail-able. This will help ensure a suitable grazing intensityand distribution and provide a more uniform allocationof forage quality and quantity for the grazing animals.

Inter-seeding desirable forages into range and pas-ture areas can be used to increase forage quality andquantity and encourage grazing in areas that receive littleor no use (Figure 8). This practice has many of the samecosts as mowing. However, it generally has a longer life.While the benefit of mowing is short-lived and must berepeated frequently, the benefits of inter-seeding can lastfor several years. The longevity of the seeding and howfrequently it needs to be repeated depends on what is


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seeded. For example, seed-ing with annual forages mustbe repeated more frequentlythan seeding with perennialforages. Also, some foragespecies can persist for onlya few years under grazing,while others may persist fordecades. For these reasons,the costs and benefits of seed-ing various forages should becarefully evaluated.

Irrigation of forages is nota common practice inHawai‘i. Still, where wateris available, irrigation ofrangeland or pastureland candramatically increase thequantity and quality of for-age available. Sources of ir-rigation water in Hawai‘iinclude domestic water sup-plies, wells, rainfall catchments, and streams. Each ofthese sources has different associated costs. While draw-ing water from domestic sources may be less expensiveto develop, it is a continual expense. On the other hand,the high initial cost of infrastructure development forwells and catchments is greatly reduced when spreadover the lifespan of such developments.

Delivery of the water to the range or pasture systemcan be accomplished in a number of ways. Water can betransmitted from the source to the site of irrigation viapipe or ditches. It can be spread over the land surfacevia sprinklers, flooding, or by a series of spreadertrenches. Obviously there are different costs associatedwith each system, and the manager needs to determinewhich would work best for the particular situation.

Construction of sheltersRecall that the second most critical element determin-ing how an animal moves across the landscape is themaintenance of thermal balance. Thus, while it is notcommon practice in Hawai‘i, the construction of shel-ters to provide livestock with relief from sun and windwill greatly improve their performance. In addition, shel-

ters can be strategically placed in order to draw animalsinto areas that would otherwise receive little or no use.Many areas in Hawai‘i lack sufficient shelter for live-stock. It is in these areas that the construction of shel-ters will have the greatest benefit relative to the initialcost of construction. Planted shelterbelts with varioustree or large shrub species can also be used to provideadequate shelter for livestock.

SummaryForaging behavior of livestock is an important consid-eration in developing a grazing management plan. Thelivestock manager that fully appreciates how animalsmove across the landscape and the factors influencingthose movements will be able to capitalize on those fac-tors to improve grazing use and distribution. Managerscan use many techniques to influence an animal’s for-aging behavior and achieve a better distribution of ani-mals. It is important that the manager carefully considerall the costs and benefits before implementing such prac-tices. In this way a manager will be sure to choose onlythose practices that fit the situation and provide the bestreturn on investment.

Figure 8. Perennial peanut (with yellow flower) inter-seeded into a stand of signal-grass as part of a pasture improvement project on former sugarcane land along theHämäkua coast.

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Literature citedGraves, J.E., and W.E. McMurphy. 1969. Burning and

fertilization for range improvement in central Okla-homa. J. Range Management 22:165–168.

Heady, H.F., and R.D. Child. 1994. Rangeland ecologyand management. Westview Press, Boulder, Colorado.

Herbel, C.H. 1963. Fertilizing tobosa on flood plains inthe semi-desert grassland. J. Range Management16:133–138.

Holechek, J.L., R.D. Peiper, and C.H. Herbel. 1989. Meth-ods of improving livestock distribution. In: Rangemanagement: Principles and practices. Prentice-Hall,Inc. Englewood Cliffs, New Jersey. p. 250–263.

Stuth, J.W. 1991. Foraging behavior. In: R.K. Heitschmidtand J.W. Stuth (eds.), Grazing management: An eco-logical perspective. Timber press, Portland, Oregon.p. 65–83.

Wight, J.R., and A.L. Black. 1979. Range fertilization:Plant response and water use. J. Range Management32:345–348.

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