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Home , Grazing, Rotational grazing

COOPERATIVE EXTENSION SERVICE • UNIVERSITY OF KENTUCKY COLLEGE OF , LEXINGTON, KY, 40546

ID-143 Rotational Ray Smith, Garry Lacefield, Roy Burris, David Ditsch, Bob Coleman, Jeff Lehmkuhler, and Jimmy Henning

Agriculture and Natural Resources • Family and Consumer Sciences • 4-H Youth Development • Community and Economic Development EXTENSION otational grazing can help Kentucky Kentucky’s land and climate offer increase productiv- farmers the opportunity to grow large ity,R which can increase yield of animal quantities of high-quality from products per acre and may increase cool- and warm-season grasses and le- profit margins for forage-based farming gumes. However, only about one-third of systems. At the same time, rotational the pasture produced are actually grazing has the potential to used by grazing animals. In addition, • reduce cost of machinery, fuel, and much of the forage consumed is not as facilities high in quality as it should be, resulting • reduce supplemental feeding and in low animal output per acre of forage pasture waste grazed. This low-quality forage occurs • improve monthly pasture distribution particularly in late spring and summer and yield and in much of the that is • improve anima l waste distribution and produced. nutrient use Kentucky pastures are generally too • improve pastures’ botanical composi- large to ensure the even grazing that tion would result in greater forage utilization. • minimize daily fluctuations in intake With large pastures, the animal decides and quality when, where, what, and how frequently • allocate pasture to animals more ef- a plant is defoliated. Use of low-cost, Much of Kentucky’s land resource has roll- ficiently, based on nutritional needs versatile fencing to reduce pasture size ing topography and would be best used can transfer decision making from the by implementing sound systems for . Farmers and ranchers who have ad- animal to the manager, which often re- opted improved grazing practices may sults in improved utilization of available call these practices controlled grazing, forage and greater control over pasture intensive grazing, management intensive allocation. grazing, rotational grazing, or intensive Kentucky has great opportunity and rotational grazing. potential in animal-based agriculture, A rotational grazing program can and better utilization of forage is the key generally be defined as use of several to realizing this potential. If pastures Ray Smith, Garry Lacefield, David Ditsch, pastures, one of which is grazed while the are managed for better productivity, and Jimmy Henning are faculty members in the Department of Plant and Soil Sciences. others are rested before being regrazed. captured in a higher-quality stage, and Continuous grazing is the use of one converted more efficiently to animal Roy Burris, Bob Coleman, and Jeff pasture for the entire grazing season. products, animal-based agriculture will Lehmkuhler are faculty members in the without question increase Kentucky’s Department of Animal and Food Sciences. agricultural income.

2 stock nutritional needs (which can vary from animal to animal) is not limited by pasture quantity. The amount of forage in 1,000 to 1,500 lb can vary, too. It may represent only 4 inches of dense grass, or it may represent 8 inches or more forage if the stand is thin and open. Keeping an adequate supply of for- age before grazing across the full grazing season is challenging for all managers. A rotational grazing system will require the use of a mix of forages to meet the seasonal fluctuations in plant growth and livestock requirements. An almost infinite combination of forages can be used successfully. Principle 2: Maintain Forage Quality to Rotational grazing allows the manager to make the best possible match between animal needs and forage production, as on this reclaimed mine site in Perry County. Meet Animal Nutrient Needs Rotational grazing allows the manager Key Principles of allow the forage to regrow to a grazable to regulate the frequency and intensity of height. An improved grazing system will grazing to control quality, yield, utiliza- Rotational Grazing also allow alteration of the stocking rate tion, and persistence of pastures. A sound A sound rotational grazing system is to adjust to the forage’s changing growth rotational grazing system has benefits for a worthy goal for Kentucky producers. rates. forage production and utilization. These Such a system involves three principles: Continuous grazing does not allow for benefits fall into six main areas: quality, adjustment of changing forage growth regrowth, persistence, utilization, and Principle 1: rate or for rest periods to allow for forage nutrient recycling. Rotational Grazing Maximizes regrowth. Continuous grazing leads to Quality: Rotational grazing systems are Forage Yield and Availability during slow-growth periods. more likely than continuous grazing to Overgrazed pastures will not reach their maintain pastures in an actively growing Rotational grazing helps managers yield potential. state. With continuous grazing, animals make the best possible match of quan- Continuous grazing has been com- tend to return to the same area repeat- tity and quality between forage and the pared to planting a of soybeans and edly and allow forages in non-grazed livestock’s nutritional needs, which will then running a combine over the field all areas to become mature, resulting in vary with age, body size, livestock class, year long. Such a comparison makes it reduced intake and digestibility. The net and especially the production level to easy to see the negative effects of continu- result is that overall quality of the pasture be supported. Growing animals, lactat- ous grazing on pasture yield. In contrast, declines. With rotational grazing, selec- ing livestock, and livestock under stress the graze per rest cycles of an improved tive grazing is limited, resulting in forage (cold temperatures, wet weather, etc.) grazing system allow for maximum re- being more uniformly grazed and more need more nutrition than mature, non- growth of the forage, given limitations uniformly regrown. lactating stock. resulting from factors such as weather Within the pasture, forage quality var- Pasture that is leafy and green and and . ies greatly from the base of the plant to the free from anti-quality factors (such as the uppermost leaves, especially with legumes endophyte of tall fescue and undesirable Availability: Meeting the nutritional and to a lesser extent with forage grasses. weed species) will provide both high pro- needs of grazing livestock is not only a The upper half of an or red clover tein and high energy for grazing livestock. function of forage quality, but animal in- canopy, for example, contains the majority Pasture must also be made available in take as well. Every day, grazing stock need of the leaf yield. Therefore, forage quality quantities that permit grazing animals to consume forage dry matter equal to 2 of legumes is higher in the top half of the to achieve their nutritional requirements. to 5% of their body weight. For example, a 1,100-lb cow can require 22 to 33 lb of pasture than in the lower half. The crude Yield: Moving to an improved grazing dry matter from pasture daily. A 100-lb protein in the top 6 inches of an alfalfa system will increase yield per acre beyond doe can require 3 to 5 lb of dry matter canopy, for example, can be twice that of that of continuous grazing. Improved from pasture daily. Pastures should the lower 6 inches. (Energy content fol- grazing systems allow for quick defo- contain 1,000 to 1,500 lb of usable forage lows a similar pattern, although it doesn’t liation of the forage to a target residual dry matter per acre so that meeting live- decline as sharply toward the lower part height followed by enough rest time to of the plant.)

3 This layering of quality within the pas- ture canopy has practical implications. Grazing management that promotes the removal of the top half of the canopy to support maximum gains is a technique called top grazing. Stocker cattle are ex- cellent as top grazers because they select 3" the highest quality forage and maximize 1.5" their average daily gains. Significant residual forage remains, however, when top grazing is used. This residual material, though lower in quality, is still valuable for dry cows or other animals with lower nutritional needs than stocker cattle. Fol- lowing top grazers with dry cows or other livestock with lower nutritional require- ments is known as leader/follower grazing or first-and-second grazing. This system allows for maximum forage utilization as well as high levels of animal output per acre. Figure 1. Effect of grazing height on legume and grass regrowth in a grazed pasture. From The quick, nonselective grazing that Blaser, et al., 1986. Virginia Polytechnic Institute Bulletin 86-7. occurs with rotational grazing is an ad- vantage in grass-legume pastures (Figure 1) because it enables legume regrowth systems lead to slow top growth and changing the method of grazing from and grass regrowth to occur at about the lower water infiltration into the soil and continuous to weekly or daily rotations same rate. If only top grazers are used so uptake by the plant. increased the persistence of big blue- that grazing heights remain high, grass Persistence: Rotational grazing will result stem. University of Georgia researchers regrowth tends to be faster. in greater persistence of forage species reported that repeated close grazing of Regrowth: Rotational grazing and that regrow from stored carbohydrates endophyte-free tall fescue caused a weak- managing to maintain both adequate and are sensitive to overgrazing or re- ened stand. However, the fescue survived carbohydrate reserves from root or peated defoliation. It also helps species in those endophyte-free pastures that had stubble and proper residual leaf area will persist during periods of drought stress. 4 inches of residual growth maintained result in maximum regrowth rates. The In University of Missouri research, across the season. rate of regrowth by forage species after defoliation (mowing or grazing) is related to the amount of leaf area remaining and Figure 2. The orchardgrass plant on the left was clipped weekly to 1 inch for one month to carbohydrate reserves in the root system, simulate continuous grazing. The orchardgrass plant on the right was clipped at the begin- both of which supply energy needed for ning and end of the month to 3.5 inches to simulate rotational grazing. For the plant on rapid regrowth. the right, the value of rotational grazing is apparent after six days of regrowth. The rest cycle in a rotational grazing system allows carbohydrate-cycling spe- cies (such as alfalfa, red clover, big blue- stem, switchgrass, and indiangrass) to maintain proper energy reserves to fuel regrowth. Rotational grazing can also benefit forage species that rely more on residual leaf area for regrowth (- grass and tall fescue), because grazing pressure can be managed to leave enough green leaf tissue to power that regrowth (Figure 2). Grazing that removes most of the available top growth of grasses leads to death and sloughing of large portions of grasses’ fibrous root systems. Small root

4 Guidelines for Designing Rotational Grazing Systems The whole should be planned, followed by development of the rotational grazing system as time and money allow. This approach will limit the number of times fences will need to be moved. Lanes can be a positive in the system. They are necessary if there is a dairy, and they also • make separating sick cattle easier • make Al breeding much easier • allow cattle to be put where they need to be Two lanes side by side and rotated back and forth will help control .

Rotational grazing keeps pastures higher in quality than does continuous grazing and Lanes can also be a negative force: favors the growth and persistence of legumes. • 15 percent of is left in the alleyway. • Cows will drink less if they have to travel too far to water.

Utilization: Most pastures contain a sium (K2O). Grazing animals excrete, in Long, round corners make it easier to great deal of forage that is never con- their feces and urine, between 70 and 90 mow or crop when fencing around the sumed and eventually decays. Traditional percent of the N, P, and K they consume better soils on the farm; fence for the most soils benefit. continuous grazing systems may use only from forage. Since a mature cow (1,200 30 to 50% of the available forage. The rest lb) on pasture or consuming hay eats The squarer the paddock, the better. However, the smaller the paddock, the of the forage is either trampled, soiled, or approximately 5½ tons of forage per year, less critical the shape. of little value because it overmatures or a significant amount of nutrients moves Every paddock should have water. dies. Most of this loss occurs with under- through their digestive system. Manure utilized fall stockpiles and during periods can be a valuable resource in maintaining Make sure you have a good mix of warm- and cool-season forages and of rapid growth where there is surplus pasture soil fertility. a plan to use them to balance forage beyond what is needed for livestock. Rotational grazing provides better ma- availability throughout the year. When the appropriate stocking density nure (fertility) distribution than typical Fencing should not be put up all at is used, shortening grazing periods to continuous grazing, in which most of the once; it should be a learn-as-you-go three to seven days increases utilization manure and urine is distributed close to process. Make sure good-quality per- 50-65%; to two days, 55-70%; and to one shade and water. Research has shown that manent fencing is used where needed, day, 60-75%. soil-test P and K values are often three but also use temporary fencing. Integrate the fencing system with live- Nutrient Recycling: Pasture fertility to five times higher within 50 ft of shade than are average levels in the general pas- stock handling facilities so cattle can be represents a real opportunity for Ken- treated or moved to a handling facility tucky livestock producers. Kentucky ture. The smaller paddocks and shorter easily from any paddock on the farm. distance to water in rotational grazing surveys show that soil testing is done on Use as much of the usable forage as only about 10 percent of pastures. Of the systems improve manure distribution. possible to meet the nutritional needs pastures that are soil tested, 40% are be- Manure is also more evenly distrib- of livestock but still allow forages to low pH of 6.0, 45% are low in phosphorus, uted at higher stocking densities. When regrow. and 35% are low in potassium. These low the travel area of the animal is restricted, A manager should not reseed with all rates should be a concern to managers for grazing and manure distribution are new varieties until how to manage what is already there. all types of pastures, but are especially enhanced. critical for fields where legumes are to Maintaining pasture fertility solely Current resources should be used. It is with plant nutrients supplied in manure not necessary to spend a lot of money be established and grown. Ideally, plant in order to have water and fence. nutrients should be applied according and urine may be easy on some pastures Fertilizing should be done where it will to soil test recommendations to achieve but more difficult on others. Realistic monitoring of pasture fertility through do the most good following soil test desired levels of pasture production. recommendations. A ton of grass-legume forage har- soil testing (in general, every three years) and grazing practices that encourage To make rotational grazing successful, vested as hay removes 35 to 45 pounds of managers must gather information, nitrogen (N), 10 to 15 pounds of phospho- more uniform distribution are essential. make a plan, put a system in place, rus (P2O5), and 40 to 50 pounds of potas- and then look to see which parts are working.

5 How to Know When to Move to Fresh Pastures The right time to rotate pastures depends on many factors. Making the following six observations can help with the decision: Look down. Has the present paddock been used as much as desired, or is there too much forage left? In general, most new rotational grazing managers tend to allow livestock to overgraze pastures. A good rule when starting out is to leave a little more forage than seems necessary, which means live- stock will need to be moved often. Look ahead. Is the next paddock ready for grazing? How fast is pasture A good rotational grazing system allows the use of high-quality forages such as alfalfa, growth? Fast growth may indicate the which requires rest periods after grazing and in the fall. need to speed up rotation or harvest some paddocks for hay. Slow growth signals the need to lighten stocking rate, add acres, or feed hay. University of Missouri researchers • Square paddocks generally result in Look at the animals. Do the animals have conducted several studies over the more even manure distribution than appear hungry, and are they in good past five years on fertility and manure paddocks of other shapes. condition? Livestock can let a manager management in pastures. Their work • When setting up a grazing system, know when they want to move, but resulted in the following conclusions, keep in mind that any landscape posi- their desire to move may be too soon for optimum pasture utilization. High- summarized here: tion that looks cool and comfortable to performing animals should be moved • Alley way paths to water of ten become people (north- and east-facing slopes) more often, however. areas of significant manure and urine will also appeal to livestock. Setting up Look behind. How fast is the last deposition, which can result in a loss paddocks and rotations to minimize paddock regrowing? Periods of slow of plant nutrients from manure best the number of days that livestock can growth may signal the need to slow utilized on pasture. These high-traffic camp at these sites will more uniformly the rotation, reduce stocking rate (by pathways can also be the primary distribute manure over the entire adding grazing acres or by selling or sources of parasitic larva that hatch pasture. moving stock), or feed hay. Slowing the rotation (more days per paddock) from feces of small ruminants. (Ac- makes animals graze closer and gain cording to the UK Veterinary Disease Principle 3: less, and future regrowth from these Laboratory, parasitism is the leading Economic profit can be realized “overgrazed” paddocks will be slower. cause of small ruminant death in through improved livestock Look at the weather. Approaching Kentucky.) efficiency and productivity. rain can signal the need to move from • Shade trees in pastures are major sites pure legume to grass-based pastures of manure accumulation; however, Rotational grazing produces eco- to prevent pugging of the soil and the availability of shade is important nomic profit by allowing the manager to damage to the legume stand. Animals should be removed from johnsongrass in hot weather and is desired in most optimize animal performance and forage utilization. By switching from continuous and sorghum-sudan type pastures systems. before frost. • Grazing systems with more frequent grazing to rotational grazing, animal Finally, look at the calendar. During rotations will result in more uniform gain per acre generally can be increased significantly, though individual animal the active growing season (April to distribution of manure and plant October), residual forage height should nutrients across a pasture. Frequent performance actually may decrease be managed to allow fast regrowth. On rotations can also serve to interrupt slightly. Farmers often increase stock fall and winter stockpiled pasture, graze life cycles of some livestock parasites numbers to capitalize on all of rotational longer and closer on each paddock to grazing’s benefits for quality and quantity use forage that would otherwise be lost and may reduce parasitic pressure. during the winter. • Fencing paddocks to minimize land- of pasture growth. scape variation will encourage more Good management of pastures, pad- uniform grazing and manure distribu- docks, and rotation schedules can lead tion. For example, managers should to increased gain per acre. For example, fence slopes separately from bottoms workers in several states have found that and ridgetops. rotational grazing will increase pounds of per acre from 35 to 61% (Table 1).

6 Increasing beef yield per acre can result in a reduced forage cost per pound of gain. More beef per acre at a lower cost of gain potentially leads to greater profit. Dairy net profit for rotational grazing in Pennsylvania was 72% greater than for continuous grazing ($129 vs. $75, Table 2). Rotational grazing as a dairy farm enterprise was more profitable per acre than either hay or corn silage, based on Pennsylvania budgets. Finally, a study from the University of Georgia (Table 3) showed several ben- efits from rotational grazing compared to continuous grazing. These benefits included an increase in stocking rate and total calf gain per acre, with a reduction in hay fed per cow. These results were Rotational grazing enables managers to use high stocking densities and short grazing realized without significantly reducing periods to increase utilization and decrease animal selectivity in grazing. calf weaning weight or pregnancy rate.

Layout and Design In most situations, the best way to the gate between two pastures—dividing Developing grazing systems involves start is to make a few simple or basic an existing pasture in half is the start of subdividing large pastures into smaller improvements in the current grazing sys- a rotational grazing system. pastures or paddocks (cells) that give the tem, which will begin the learning curve Being flexible is fundamental to manager control over how long cattle are and allow the manager to develop the putting rotational grazing systems to- allowed to graze a particular area (pad- rotational system at a comfortable pace. It gether. The should do what he or dock) before they are moved. No single will also minimize “improvements” that she thinks best, but should be open to blueprint or model exists for setting up later prove to be less than optimal. A lot change—and continual planning—before a grazing system that will provide maxi- of progress can be made by simply closing driving the first post. mum control. Every Kentucky farm is unique; many different solutions are pos- sible and workable. The most important Table 2. Dairy enterprise budgets per acre for pasture and forage crops. factor in developing a rotational grazing Intensive Continuous Corn system is to develop one that is right for Pasture Pasture Hay Silage the farmer, the farm’s resources, and the Gross return in field $193 $112 $196 $313 land’s capabilities. Average storage loss 0% 0% 12% 13% Laying out or designing a pasture Gross return after storage $193 $112 $172 $273 system involves many decisions, includ- Total cost $64 $35 $156 201 ing how many paddocks the system will Profit $129 $75 $20 $58 have and their size, location of water Source: Farmer Profitability with Intensive Rotational Grazing. L. Cunningham and G. Han- sources, lane placement, and livestock son, Penn State University. 1995. Note: Feeding loss was not measured. Pasture was valued based on dry matter nutrient value compared to the nutrient value and market price of dry hay. flow around working facilities.

Table 3. Effect of year-round continuous vs. rotational stocking of endophyte-free tall fes- Table 1. Increase in beef gain per acre in cue and common bermudagrass mixed grass pastures at Central Georgia Branch Station, rotational grazing compared to continuous Eatonton, Ga., 3-year average. grazing. Continuous Rotational Difference, % State % Increase Stocking rate, cow-calf units per 0.50 0.68 +36 Arkansas 44 acre Georgia 37 Calf weaning weight, lb 502 502 0 Oklahoma 35 Total calf gain per acre, lb 251 342 +36 Virginia 61 Cow pregnancy rate, % 94 93 0 Hay fed per cow, lb 2,390 1,690 -29 Source: Dr. Carl Hoveland, University of Georgia.

7 Both cool- and warm-season forages are needed for a sound graz- A leafy, high-quality mix of grasses and legumes can be achieved ing system. This field of switchgrass in Owen County provides sum- through well-managed rotational grazing. mer pasture for these stockers and complements tall fescue, which is used in spring and fall.

Physical Components of Forage Supply season species (tall fescue, orchardgrass, timothy, white clover, and red clover) A good rotational grazing system Rotational Grazing Systems perform best in spring and after the begins with a forage system that allows A good rotational grazing plan will weather cools down in the fall. Warm- the maximum number of grazing days include four main physical components: season species (bermudagrass, eastern per year with forages that are suited to forage supply, fencing system, water sup- gamagrass, alfalfa, and annual lespedeza) the land, livestock, and the manager’s ply, and shade. perform better in midsummer. abilities and objectives. Forage species should be matched to Forage can be divided into two cat- soils that will maximize their yield and egories: cool-season and warm-season growth. For example, tall fescue and species, which differ in their seasonal white clover are well adapted to thin soils ability to produce grazable yield. Cool-

5. The next step is more difficult and requires patience. Subdivide Steps in Setting Up a Grazing Program the permanent fields in near-equal sizes, keeping the pad- 1. Start with a good aerial photograph of your pastures—the docks as square as possible. Plan and plan again. Draw lines, larger the scale, the better. These photographs are avail- think, erase, and try again. Even when you start to fence, use able at the local office of the Farm Service Agency office and temporary fencing so it will be easy to change. Try to use exist- USDA National Resources Conservation Service (NCRS) online ing water if possible. sources. Just be sure you have a scale map. A soils map is also 6. At this point you are already doing a good job of grazing, and a valuable tool. A soils map, a list of descriptions , and some it is time to refine the process. You should have enough pad- professional guidance are available through the NCRS. A grid docks so that your livestock will be moving every seven days or for counting acres is also handy. It will help you even up the less. Place water in every paddock. This practice will allow you odd-size fields in total acres. to make the paddocks as square as possible. You should also 2. On your aerial photo, mark the property line, all roads, build- have shade in as many paddocks as possible, especially those ings, livestock-working areas, parlors, other permanent that will be grazed in the summertime. facilities, and existing water and shade. 7. At some point you will want a system that will allow you to 3. Using the soils map, mark the major soils changes, consider- move your livestock to any part of the farm as needed, which ing both slope and quality of the soils. Then adjust these lines will require a system of alleyways or lanes. All lanes should to make them workable as markers for your first permanent allow you to take an animal anywhere you need to if she has fences. trouble birthing, is sick, or is scheduled for deworming and 4. Draw around any crop fields if their soils are different from the vaccination. This system will also allow you to graze more than soil breaks. You may also want to identify areas with different one at a time. You may also want to build some sorting forages, such as alfalfa or warm-season grasses. Divide the squares to separate livestock as needed without moving them farm along existing water sources. to the barn. This system of alleyways/lanes will let you be in Your completed map should control of the grazing on your farm and make it easy to move • be a basic grazing system with water in each field cattle to your handling facilities, chutes, or scales. • be divided based on productivity • have enough fields to begin rotational grazing

8 or steeply sloping sites that hold water for growth in spring but often become droughty in summer. Because they hold little moisture for summer growth, these fields would be poor choices for maxi- mizing productivity of warm-season forages. In another example, highly productive forages such as alfalfa should be planted on the deepest, best drained soils. Most forage systems in Kentucky are based on cool-season forages such as tall fescue, orchardgrass, white clover, and red clover, which produce an abundance of forage in the spring and most falls but are not productive in mid-to-late sum- mer. The two biggest challenges in de- High-tensile electrified wire is a viable and economic alternative to conventional fencing veloping a balanced forage system are materials such as woven wire, and it enables a fencing system to be built more quickly. maintaining supplies of quality forage in midsummer and extending the grazing season as long as possible into the fall and early winter. Many forage species are capable of midsummer production, but they all have disadvantages that prevent their use for some producers. Alfalfa, as noted above, requires deep, well-drained soils, and it also requires a high level of management for best performance. Eastern gamagrass and other native warm-season perennial grasses are slow to establish, and seed is expensive com- pared to other cool-season forages. Sum- mer annuals such as sorghum sudangrass and the millets must be seeded each year and require inputs of nitrogen to maximize yield. However, a balanced and well-planned grazing system will Temporary fencing materials such as tread-in posts and electrified polytape allow for quick include some acreage of warm-season subdivision of existing pastures. forages that can be used as rescue crops in midsummer or in short periods of heat and drought stress when cool-season that provide pasture in fall and winter. for growth than reproductive operations, species are less productive. Fall pasture options include stockpiled in which the mother’s milk helps support An efficient grazing management plan tall fescue, small grains, turnips or other calf/kid/foal performance. should attempt to match pasture growth brassicas, and annual ryegrass. to animal needs and offer the potential Stocker operations are usually one of Fencing System for minimum pasture to be harvested two types: and stored as hay or silage. Livestock sys- Use of low-cost, versatile fencing to • buying in the spring and selling in the tems managed for reproduction will have reduce pasture size can transfer decision fall the greatest forage needs in the birthing making from the animal to the manager. • buying in the winter, overwintering on and breeding season; forage needs will Rotational grazing usually relies on an hay or stockpiled pasture, and turning drop off after weaning. Spring-calving/ electrified fencing system to subdivide out on spring pasture kidding need the quality and quan- larger pastures into smaller grazing units. tity of spring and early summer pasture Development of high-voltage, low-im- Both systems provide freedom to sell but must rely on stored forage in late pedance electric chargers allows fencing all or part of the stockers as forage growth winter. Fall-calving/kidding herds rely of large acreages without losing voltage slows. Stocker operations are much more more on hay or silage and forage crops due to fence-line . These ener- sensitive to forage quality and quantity gizers send high-voltage, short-duration

9 pulses down the fence. Although 2,000 volts is considered adequate to control most stock, most fence chargers and systems should start with around 7,000 volts. There is no standard system for com- parison of energizers, and every manu- facturer has a different scale. Joules are the most common measure of power in energizers. The joule rating is calculated using a combination of voltage, amper- age, and pulse duration. Changing any of them affects the rating. Generally speaking, fencing system needs will grow, so obtain enough energizer capacity to cover future needs. Energizers come in mains, or plug-in units, as well as battery and solar units. It is best to use a plug-in Electrified polytape (available in widths up to 1½ inches) is very visible and can be used for energizer if possible because it delivers subdivision fencing for pasture. The twist in the polytape makes it flutter in the wind, more charge (joules) per dollar spent. resulting in greater visibility. A good ground is essential for the ef- fectiveness of any electric fence system. The energizer’s ground is like a radio In Kentucky, the most economical galvanized (Class III). Smaller diameter antennae. A large radio collecting waves controlled grazing fencing system is high-tensile wire is also now being used, from a long distance needs large anten- often one that includes a combination of particularly on interior division or pad- nae, and a large energizer powering a lot permanent, electric, smooth, high-tensile dock fences. This type of wire includes of fence needs a large ground system with wire fencing and temporary portable 14½-gauge and 16-gauge thicknesses. a minimum of three 6-foot galvanized polywire (available on reels). An advan- The use of such wire has implications for ground rods. These rods may be placed tage of the reel is that it allows rapid setup energizer selection (since smaller wire in the ground at an angle if there is less and takedown of fence for temporary has a greater resistance to current flow) than 6 ft of soil. Ground rods should be arrangements or strip grazing. Portable and in the length of fencing that can be driven in a damp place, if possible, such fiberglass fence posts are often used energized. as under the drip of the barn roof or in a with the portable braided wire, with one For interior and temporary fences, a low area. strand of wire used for grazing of large more flexible, low-tension wire is popular. An electric fence can be built in either animals and two strands for calves. Since Small-diameter, high-tensile wire can be of two ways. With the all-live system, ev- it is electrified, high-tensile wire for the used, but many producers prefer a slightly ery wire in the fence is energized, and the permanent fence often can be installed softer grade of wire since it is somewhat conduction of electrons back to the en- using low-tension techniques. easier to work with when moving and ergizer depends on the soil. This system handling the fence. An excellent alterna- is generally effective in the southeastern Types of Fencing tive for temporary installations is braided United States because soils in this region Following is an overview of several wire, which contains fine-gauge steel have high mineral content and adequate types of fencing and their appropriate wires braided with polyethylene strands rainfall. Also, in an all-live system, a limb place in a controlled grazing system: into a wire, ribbon, or tape. These wires or branch can fall across the wires and For permanent boundary fence instal- work quite well for installations of up to the fence will remain energized. lations, -type high-tensile 1,200 ft. Because of the lower cross-sec- The other system is the hot ground wire is suggested. This is 12½-gauge tional area of steel, energizer requirements system, which has one or more fence high tensile smooth wire that is heavily differ from those of smooth high-tensile wires connected to the positive termi- nal of the energizer and the rest of the wires connected to the ground terminal. Table 4. Sample water requirements for cattle, gallons per head per day. This system works well in sandy, arid Gal per lb 500-lb Calf, 750-lb Calf, 1,100-lb Dry 1,100-lb areas—moist soil is not necessary to Temp, F DM 12 lb DMI 16.6 lb DMI Cow Nursing Cow deliver a charge. The main disadvantage 40 0.37 4.4 6.1 7.4 8.1 of the hot ground system is that it is high 60 0.46 5.5 7.6 9.2 10.1 maintenance. If any charged wire touches 80 0.62 7.4 10.3 12.4 13.6 a ground wire, the whole system shorts 90 0.88 10.6 14.6 17.6 19.4 out. Rarely is a hot ground system needed Source: Winchester and Morris, 1956. in the eastern United States.

10 Consider using the raw water source of springs. They are an excellent source of water but are as different as grazing systems. A stream of water the size of a pencil and a large collection tank could water up to 70 to 100 beef cows. Also consider ponds as a water source. Water- ing from tanks below ponds is strongly preferred to watering directly out of the pond. The pipe should be installed under the dam when building the pond. The pipe then can go directly to a tank or to a collection basin. Water can then be pumped anywhere on the farm. Shade Shade is necessary to maximize live- An effective water distribution system is essential to the grazing system. This permanent stock performance. Heat stress in the water tank was developed from a spring and provides an inexpensive source of water on a absence of shade can have several effects. Metcalfe County farm. Black-hided cattle, for example, can suf- fer from heat stress on bright sunny days in late summer when air temperature is wire. Some newer braided wires have Cooling water has been shown to reduce comfortable. more steel (thus less resistance), so they heat load and allow increased feed intake. Cows with natural shade spend more can be used in longer runs. Studies with dairy cattle have shown the time grazing and less time standing than most acceptable water temperature to be cows without shade. Natural shade from Water Supply in the 60° to 80°F range. Using insulated large, well-canopied trees is the most Water is possibly the most important, drinking receptacles or building shades effective. This type of shade intercepts but least considered, nutrient for live- over the water tank can reduce heating radiation from the sun and provides stock. It is needed for virtually every body from the summer sun. Insulated or heat- some air cooling through evaporation of function. Many factors influence water ed waterers will be needed for pasturing moisture from leaves. intake. As air temperature increases stockpiled forage in late fall and winter. Artificial shade also will reduce heat above 40° F, water intake increases per Location of water in the grazing site stress, but attention must be paid to the lb of dry matter consumed (Table 4). will greatly influence grazing distribu- type, orientation, and square footage per Lactating livestock require more wa- tion. During hot weather, livestock con- head. Hay or straw on wire are the best ter than dry animals, and at a constant gregate nearer the water source, resulting types of artificial shade because they temperature, livestock consuming more in less use of pasture farther from it. have high insulation value, low bottom feed need greater water intake. Similarly, Research has shown that the maximum surface reflectance, and loss of absorbed if water intake becomes limited, feed distance cattle will travel to water with- heat to the air by convection. Aluminum intake will decrease, and performance out decreasing grazing uniformity is 800 panels painted white on top and black on will be limited. Lush pasture can be ft. As travel distance increases above that the bottom are also effective. Direct heat 70% or more water and can decrease the amount, pasture use decreases. from the sun is well reflected by the white amount of water that must be supplied in Developing Water Sources: Each situ- paint, and the black bottom absorbs the water system, at least on a short-term ation is different, and flexibility is re- the heat from the ground and animals. basis. warded when it comes to developing Snow fence or shade cloth may also be Water intake restrictions can result water sources. used, but they are less effective than the from inadequate access of livestock to the Although there is a monthly cost, other materials mentioned here. Both let water source, water temperature, and wa- public water supplies are often the best through some sun, so they don’t provide ter quality. Quality is determined by total solution to livestock water needs when complete shading. For maximum shad- dissolved solids (TDS). High TDS levels development, maintenance, and reli- ing, the long axis of the artificial shade may not pose serious health risks but ability are considered. At some point in should be oriented on an east-west line. may decrease total water intake. Water developing a management system, a Most research shows that 45 to 60 sq ft exposed to direct sunlight (tanks, ponds) pressurized water system will become a per cow is desirable. can become quite warm in the hot days necessity. It will provide water where it is of summer, resulting in lower intakes. needed instead of forcing the manager to Regardless of why decreased water work with a few water sites. intake occurs, performance will suffer.

11 triangle, pie, etc.). Square paddocks allow animals to obtain their daily ration of forages with a minimum of grazing time, effort, and trampling damage. Studies have shown that square paddocks are more economical to construct than other shapes (Figure 3). Having exactly square paddocks is not absolutely necessary, but avoid long, narrow paddocks. Whenever possible, fence across slopes rather than up and down slopes. and Rotational Grazing As a spot grazer, horses are selective in which parts of the plant they will graze. Temporary or seasonal water systems can reduce distance traveled to drink and increase Typically, horses select the more imma- pasture utilization. Small to medium-sized tanks can easily be moved from paddock to ture plant material, even when adequate paddock. forage is available. Horses also show preferences for particular forage types. UK research has shown distinct grazing Pasture Number and Size University of Kentucky modeling preferences in which horses select one studies compared continuous grazing species of grass over another to the point One of the most frequently asked with rotational grazing (four paddocks that they overgraze that species while questions by producers who want to start and eight paddocks) for beef production virtually ignoring other available forages. a rotational grazing program is “How on endophyte-free tall fescue. Produc- This preferential grazing behavior can many paddocks should I have?” Answers tion ranged from 683 lb per acre for result in some pasture areas being grazed appear contradictory: continuous grazing to 810 lb per acre to bare ground. • One pasture can be grazed just as ef- for eight paddocks. The most striking ficiently as many. difference was the four-paddock system, or which showed an increase of 112 lb of Figure 3. Effect of pasture shape on amount of fencing needed around 1 acre. • Regardless of how many paddocks beef per acre over the continuous system. there are, divide them again, and more The eight-paddock system showed a Shapes Length money can be made. 127-pound increase in beef per acre over The truth lies somewhere between the continuous system. The rotational 744' these extremes. system increased returns by $77 to $103 In general, one should consider start- per acre. ing with five to 10 paddocks, which will University of Missouri research- 836' allow a paddock to be grazed in three to ers compared the effect of 3-, 12-, and seven days and rested for 25 to 30 days. 24-paddock systems on the performance In most cases, four paddocks should be of beef cow-calf and stockers grazing L = 2 x W 888' considered a minimum. Table 5 contains cool-season grass and clover. When all several formulas that can help determine costs and returns were compared, the 60° paddock number and size. three-paddock system resulted in $84.36 951' Some systems in the United States and increase above pasture, animal, and inter- 60° 60° est cost, the 12-paddock system showed New Zealand have as many as 30 to 60 or 45° even more paddocks. Many of these are a $115.43 increase, and the 24-paddock 1,007' dairy where pastures are changed system showed a $117.74 increase. These after each milking. Several studies have results suggest that going to 12 paddocks 45° been conducted in the United States, yielded a profit of $31. Going from 12 to and they generally show that for most 24 paddocks resulted in only a $2.31 per L = 4 x W 1,040' beef operations, the added benefit above acre increase. 8 to 12 paddocks may not be worth the Shape of individual paddocks is 1 43,560 87,122' additional cost of fencing, water, labor, important. Within practical limits, and management. square paddocks are the most efficient Source: Garry Lace eld, University of Kentucky. compared with other shapes (rectangle,

12 Table 5. Grazing mathematics.

days of rest • Days of rest: Values range from 10 or less for grasses during periods Number of paddocks = + 1 of rapid growth to 30 for legumes and even more for periods of slow days of grazing growth. • Days of grazing: Varies from 1 to 7 and up. Shorter times on a pad- Example: dock yield greater season-long utilization and less waste, selectivity, 28 days rest and regrowth grazing. Number of paddocks = + 1 = 8 paddocks 4 days grazing

Acres required per paddock = • Weight: Weight per head, in pounds. • Percent DMI: Percent dry matter intake, ranging from 2% to 4%. weight x % DMI x number x days per paddock • Number: Number of head to be grazed. • Days per paddock: Amount of time that animals are to be allowed DM per acre x % utilization to graze in a given paddock. Values can range from 1 to 7 and up. To keep animals from grazing regrowth, keep days per paddock to 7 or Example: less. Acres required per paddock = • DM per acre: Estimate of total forage dry matter available per acre as the animals enter a paddock. 500 lb x 3% x 100 head x 4 days • Percent utilization: Portion of the available forage per acre that = 5 acres 2,000 lb per acre x 60% animals will consume during a grazing period. Improved grazing systems can result in utilization of 60% for grasses and 75% for legumes.

Total acres required per grazing cycle = • Number of paddocks will be determined by the length of the rest and grazing periods. number of paddocks x acres required per paddock • Acres required per paddock are determined by amount of forage needed each day by the grazing herd divided by the grazable forage dry matter per acre. Example: • The number of acres needed per grazing cycle will vary with the Total acres required per grazing cycle = growth rate of the forage. As the growth rate slows, the number of acres required to supply 3% DMI and maintain 4 days on and 8 paddocks x 5 acres per paddock = 40 acres 28 days off a paddock will increase.

number of animals to be grazed • Stocking rate and stocking density are often confused. Stocking rate Stocking rate = applies to an entire grazing period (in this example, 32 days) or can total acres grazed be thought of as a season-long or whole-farm statistic.

Example: 100 head Stocking rate = = 2.5 head per acre 40 acres

number of animals grazing on a paddock • Stocking density is the stocking rate at a given point in time. In Stocking density = this example, 100 steers are grazing in a 5-acre paddock, which paddock size is a stocking density of 20 head per acre. Stocking density can be expressed as the number of pounds of grazing animals per acre at a given point in time (in this case, 10,000 lb per acre). Example: 100 head Stocking density = = 20 head per acre 5 acres

13 When rotational grazing is practiced, warmer summer days, because summer sure to larva of gastrointestinal parasites. horse owners can, to some degree, con- heat and exposure to sunlight helps con- Unfortunately, few studies have been trol spot-grazing behavior. Horses can trol parasites. Horse owners should allow conducted in Kentucky to measure the be put into a paddock when the average 21 to 28 days between rotations for forage benefits of managing in a rotational height of the forage is 6 to 8 inches and regrowth. Amount of regrowth will be grazing system. removed when the average height of the affected by environmental conditions In 2006 and 2007, a study was con- forage across the paddock is 3 to 4 inches. and the amount of forage material left in ducted in Greenup County, Kentucky, Because of a horse’s grazing behavior, the paddock. to compare rotational grazing vs. con- portions of the paddock may be grazed to Pay attention to how much forage is tinuous grazing in a produc- below the 3-inch level, while other areas available, and let forage height dictate tion system. Based on the results of this may still be at 6 to 8 inches, which can when horses are moved to a new pasture. study, rotational grazing did not result in result in preferred areas being extensively It is better to move a day early than a day improved animal weight gain or a signifi- overgrazed and taller forage not grazed at late. If regrowth of the pasture is slow, cant reduction in pressure from internal all. If overgrazing or spot grazing begins horse owners may need to consider hold- parasites (based on FAMACHA scores) to occur, it is important to rotate horses ing horses in an area and feeding hay to compared to continuous grazing. These to the next paddock. Mowing may be allow pastures to regrow to prevent seri- results were probably affected by the ex- required in the first paddock to even ous overgrazing. Well-managed pastures treme dry weather conditions both years pasture height so that spot grazing is with an effective rotational system can and the need for feed supplementation. reduced in the next grazing cycle. reduce feed costs, maintain a good forage However, does showed lower final fecal With a well-managed rotational sys- base, and increase forage produced. parasite egg counts on the rotational vs. tem, mature horses at maintenance will continuous grazing, which suggests that generally maintain body weight. Grazing Goats and Rotational Grazing barber pole worm egg production may projects at UK with mature horses on a Goats are known as top-down graz- be affected by the grazing system. In gen- cool-season pasture maintained body ers, meaning that they prefer to graze eral, forage availability was greater in the weights over a number of summer graz- vegetation above their shoulders and rotationally grazed paddocks than in the ing periods. In addition, grazing projects work their way down the plant. Other continuously grazed pasture through- at UK with bermudagrass have shown livestock species, including cattle, out the grazing season. Care should be that mature horses can maintain body and horses, prefer to graze much shorter taken when designing rotational grazing weight throughout the summer. In 2009, vegetation than goats. Goats also tend to systems for goats, because systems with a group of 2- and 3-year-old horses had prefer browse (shrubs and small trees), common water, shade, or alleyways will acceptable growth rates, with minimal while cattle and horses prefer grasses. allow frequent close grazing in areas that supplementation, while on pasture. Grazing systems that allow all types of have high parasitic pressure. Horse owners should consider the fol- pasture plants time to recover are more Fencing costs may be higher for goat lowing management practices when they likely to meet the grazing preference of vs. cattle production. Woven wire fencing are rotationally grazing their pastures: goats. for predator control on perimeters and Mow the paddock to a 4-inch height In theory, goats managed in a ro- multi-strand fencing for interior fenc- after moving the horses from the pad- tational system should realize greater ing may be necessary for keeping goats dock to help control spot grazing. average daily gains or at least maintain in designated paddocks. Other benefits Drag the paddock to disturb and scat- their weight compared to those grazed of rotational grazing for goats include ter the manure to help it break down and in a continual system. Rotational grazing maintaining a sustainable forage base, reduce its buildup. Ideally, horse owners should also allow goats to graze higher in increased forage production, and a more should drag the paddock during the the forage canopy, reducing their expo- even distribution of manure.

14 Good Grazing Management Table 6. Guidelines for rotational stocking of selected forage crops. Target Height (inches) Usual Days Good grazing management achieves Crop Begin Grazing End Grazinga of Rest the right balance between standing for- Alfalfa (hay types) 10-16 2-4 35-40 age availability, forage utilization, and Alfalfa (grazing types) 10-16 2-4 15-30 animal performance. The good manager Bahiagrass 6-10 1-2 10-20 stocks pastures heavily enough to graze Bermudagrass 4-8 1-2 7-15 available forage down to a target height Big bluestem 15-20 10-12 30-45 that will allow rapid and maximum Caucasian bluestem (and other Old 10-20 4-6 14-21 regrowth (during the growing season) World bluestems) without compromising nutritional needs Clover, white, and subterraneanb 6-8 1-3 7-15 of livestock. A good manager will observe Clovers, all othersb 8-10 3-5 10-20 pastures frequently for overgrazing and Eastern gamagrass 18-22 10-12 30-45 undergrazing and will periodically adjust Fescue, tall 4-8 2-3 15-30 the stocking rate or movement of cattle Indiangrass 12-16 6-10 30-40 as needed. Guidelines for beginning Johnsongrass 16-20 8-12 30-40 and ending grazing heights and usual Kentucky bluegrass 8-10 1-3 7-15 days of rest for several pasture crops are Orchardgrass 8-12 3-6 15-30 contained in Table 6. Pearl millet 20-24 8-12 10-20 A sound rotational grazing system is Ryegrass, annual 6-12 3-4 7-15 a worthy goal for Kentucky producers for Sericea lespedeza 8-15 4-6 20-30 three main reasons. Such a system Small grains 8-12 4 7-15 • helps managers efficiently use forage to Smooth bromegrass 8-12 3-4 20-30 meet the nutritional needs of livestock Sorghum, forage 20-24 8-12 10-20 • helps managers optimize forage yield, Sorghum/sudan hybrids 20-24 8-12 10-20 quality, and persistence Switchgrass 18-22 8-12 30-45 • increases profit by improving grazing Source: Excerpted from Forage Pocket Guide, developed by Don Ball, Garry Lacefield, and livestock efficiency and productivity Carl Hoveland. 1999. Note: These are merely guidelines. Stocking rates and growing conditions greatly affect for- age growth. Also, the more closely pastures are grazed, the longer the rest period gener- The components of a good rotational ally needs to be for species that are sensitive to defoliation. grazing system are a balanced forage sys- a The nutritional requirements of the livestock being grazed should be considered when tem, an electric fencing system, distrib- deciding when to end grazing. The closer a pasture is grazed, the lower forage quality uted water supply, and adequate shade will be toward the end of that particular grazing cycle. Greater residual heights may be desired for animals with higher nutritional requirements (for example, stocker cattle vs. for livestock. These components can be cows and calves). designed and customized to fit the needs b Clovers are typically grown in pastures in mixtures with grasses. White clover and subter- of each farm. High-quality pasture is es- ranean clover are quite tolerant of close defoliation; most other clovers are not. sential for Kentucky’s livestock industry, but most fields are too big to be managed efficiently, so smaller, easier-to-manage pastures in a rotational system should be considered.

15 Grazing Terminology Forward creep: A method of creep graz- Pasture: A type of grazing management ing in which dams and offspring ro- unit enclosed and separated from other Aftermath: Forage grown following a tate through a series of paddocks with areas by fencing or other barriers and harvest. offspring as first grazers and dams as devoted, primarily by grazing, to the last grazers. A specific form of first-last production of forage for harvest. Animal unit day: The amount of dry for- grazing. age consumed by one animal unit per Put-and-take stocking: The use of variable 24-hour period. Grazing land: Any vegetated land that is animal numbers during a grazing period grazed or has the potential to be grazed or grazing season with a periodic adjust- : The maximum stock- by animals. ment in animal numbers in an attempt ing rate that will achieve a target level to maintain desired sward management of animal performance in a specified Grazing management unit: The grazing criteria—a desired quantity of forage, grazing method that can be applied over land area used to support a group of graz- degree of defoliation, or grazing pressure. a defined time period without deteriora- ing animals for a grazing season. It may tion of the ecosystem. be a single area, or it may have a number Rotational stocking: A grazing method of subdivisions. that uses recurring periods of grazing and Continuous stocking: A method of graz- rest between two or more paddocks in a ing livestock on a specific unit of land Grazing pressure: The relationship be- grazing management unit throughout in which animals have unrestricted and tween the number of animal units or for- the period when grazing is allowed. uninterrupted access throughout the age intake units and the weight of forage time period when grazing is allowed. dry matter per unit area at any one point Short-duration grazing: Not an accept- in time; an animal-to-forage relationship. able term. Creep grazing: The practice of allowing The opposite of forage allowance. juvenile animals to graze areas that their Stocking density: The relationship be- dams cannot access at the same time. Intensive grazing management: Grazing tween the number of animals and the management that attempts to increase specific unit of land being grazed at any Deferred grazing: The delaying of grazing production or utilization per unit area or single point in time. in a nonsystematic rotation with other production per animal through a relative land units. Stocking rate: The relationship between increase in stocking rates, forage utiliza- the number of animals and the grazing Extensive grazing management: Grazing tion, labor, resources, or capital. management unit used over a specified management that uses relatively large Mixed or co-species grazing: Grazing by time period. land areas per animal and a relatively low two or more animal species on the same Stockpiling forage: To allow forage to level of labor, resources, or capital. land unit, not necessarily at the same accumulate for grazing at a later period. First-last grazing: A method of using two time but within the same grazing season. Sward: A population of herbaceous plants or more groups of animals, usually with Mob grazing: In the management of a characterized by a relatively short growth different nutritional requirements, to grazing unit, grazing by a relatively large habit and relatively continuous ground- graze sequentially on the same land area. number of animals at a high stocking cover, including both aboveground and Forage allowance: The relationship be- density for a short time period. belowground parts. tween the weight of forage dry matter per Nonselective grazing: Utilization of forage Vegetative: Involving nonreproductive unit area and the number of animal units by grazing animals so all forage species plant parts (leaf and stem), the nonre- or forage intake units at any one point in and/or all plants within a species are productive stage in plant development. time; a forage-to-animal relationship. The grazed. opposite of grazing pressure. Paddock: A grazing area that is a subdivi- Forage crop: A crop of cultivated plants or sion of a grazing management unit and is plant parts (other than separated grain) enclosed and separated from other areas produced to be grazed or harvested for Excerpted from Terminology for Grazing Lands by a fence or barrier. use as . and Grazing Animals, Forage and Grazing Terminology Committee, Dr. V. Allen, Chair, Pocahontas Press Inc., Blacksburg, Virginia.

Educational programs of Kentucky Cooperative Extension serve all people regardless of race, color, age, sex, religion, disability, or national origin. Issued in furtherance of Coop- erative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture, M. Scott Smith, Director of Cooperative Extension Programs, Uni- versity of Kentucky College of Agriculture, Lexington, and Kentucky State University, Frankfort. Copyright © 2011 for materials developed by University of Kentucky Cooperative Extension. This publication may be reproduced in portions or its entirety for educational or nonprofit purposes only. Permitted users shall give credit to the author(s) and include this copyright notice. Publications are also available on the World Wide Web at www.ca.uky.edu. Revised 10-2011