Forage Systems for Stocker Cattle (B 1392) University of Georgia Extension This publication provides a guide to the various forage systems that could be used for stocker development and provides guidelines for managing grazing or hay harvests for optimum forage yield and quality. 2014-10-02 13:57:54.0 2011-10-10 10:24:59.0 Forage Systems for Stocker Cattle | Publications | UGA Extension Skip to content

Forage Systems for Stocker Cattle (B 1392)

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Dennis W. Hancock, Extension Forage Agronomist, Department of Crop and Soil Sciences
R. Curt Lacy, Extension Livestock Economist, Department of Agricultural and Applied Economics
R. Lawton Stewart Jr., Extension Beef Nutritionist, Department of Animal and Dairy Science

cows grazing in a landscape

Forages can be a relatively inexpensive feedstock for stocker development in the Southeast. With the luxury of a nearly year-round growing season, beef producers in this region have a competitive advantage over producers in other regions with a shorter grazing season and cattlemen who primarily use concentrate-based rations. However, it is critical to appropriately match the animal?s nutritional needs to the forage base. This publication provides a guide to the various forage systems that could be used for stocker development and provides guidelines for managing grazing or hay harvests for optimum forage yield and quality.

Comparing Forage Systems

When evaluating or comparing forage systems for stocker development, a number of factors need to be considered. Many of these considerations are specific to the individual farm, situation, or management ability (e.g., the capability to plant, manage, and use annual forage crops; appropriateness of the site to the requirements of the forage system in question, etc.). With all other factors being equal, the primary basis for comparing forage systems includes:

  1. Average daily gain: ADG; the expected average rate of gain per animal,
  2. Gain/acre: the amount of gain expected to be produced per acre,
  3. Grazing period: the expected number of days when the forage system can be grazed at a specified stocking rate, and
  4. Stocking rate: the expected number of animals capable of being grazed on a given acre for the specified grazing period.

These factors individually influence the profitability of the forage system but they are also interrelated. The interrelationship between some of these factors can be seen in their definitions (e.g., stocking rate and grazing period) or their mathematical relationships (e.g., gain/acre = ADG x days in grazing period x stocking rate). To understand how these aspects interact, it is important to understand that the grazing pressure applied by different stocking rate levels can affect ADG and gain/acre.

Figure 1. The general interrelationship between stocking
rate, average daily gain (ADG), and gain/acre for a given
grazing period. Figure 1. The general interrelationship between stocking rate, average daily gain (ADG), and gain/acre for a given grazing period.

In general, the goal is to maintain ADGs at least above 1.5 lbs/head/day so that the animal?s weight stays appropriate to its age. However, this must be done while optimizing gain/acre, since this term is a primary determinant of profitability. Though one may think that gain/acre could be increased merely by increasing the stocking rate, this may be counter-productive. Certainly, increasing the stocking rate up to a certain level improves gain/acre (Figure 1). However, ADG generally decreases as stocking rate increases. As the stocking rate increases beyond an optimum, the lower ADG of the individuals can begin to cause gain/acre to decrease. The reason for this is that as stocking rate increases, an individual animal may not be able to select high quality forage and, ultimately, may not have enough forage available to meet its nutritional needs for high production.

Since these four key aspects are interrelated, it is important to consider them collectively when comparing forage systems. Like a jigsaw puzzle, the only way to see the whole is to simultaneously consider these four core pieces (Figure 2). In this publication, research results for a number of different forage systems for stocker development have been summarized using these four factors whenever possible. Unfortunately, not all of the research that has been done was performed in such a way as to provide all of these four factors.

Figure 2. Gain/acre, average daily gain, the days
in the grazing period, and stocking rate are interrelated
and central to understanding how one
forage system for stockering compares to another. Figure 2. Gain/acre, average daily gain, the days in the grazing period, and stocking rate are interrelated and central to understanding how one forage system for stockering compares to another.

It is also important to recognize that the provision of supplemental feed can influence or improve all four of these key factors. The results of research trials reported here are from trials where no supplemental feed was provided to the animals. This makes for a good comparison of the different forage species and indicates the species (or varieties) that would need to be supplemented more or less. Additional information about improving ADG, gain/acre, stocking rate, and grazing period with supplemental feed can be found in the Related Publications section.

Forage Systems Overview

The Southeast?s mild climate and high rainfall allow for excellent forage production conditions. More than 60 forage species are grown and used in Georgia. Of these forage crops, several are capable of producing the quality and quantity of forage necessary to support a stocker beef cattle production system. Table 1 presents a summary of the 12 forage crops that are most commonly used for stocker development in Georgia.

Table 1. Key characteristics of forage systems commonly used for pasture-based stocker development programs in Ga.
Forage
Type
Yield (tons/a)
Quality§
Cost of
Ease of Use For††
CP (%)
TDN (%)
Establishment
Production
Grazing
Hay
Annual Ryegrass
CSAG
4-5
10-20
56-74
Medium
Medium
1
3
Oats
CSAG
3-4
8-17
55-70
Medium
Medium
2
2
Rye (cereal)
CSAG
2-3
8-17
52-70
Medium
Medium
2
4
Wheat
CSAG
3-4
8-17
50-70
Medium
Medium
2
2
Arrowleaf Clover
CSAL
1.5-2
14-24
56-75
Low
Low
1
4
Crimson Clover
CSAL
1.5-2
14-24
57-75
Low
Low
1
4
Tall Fescue
CSPG
4-5
10-16
58-62
Medium
Low
1
1
Crabgrass
WSAG
2-5
9-12
58-65
Low
Medium
1
3
Pearl Millet
WSAG
4-6
8-12
52-58
Medium
High
3
4
Sorghum-Sudangrass
WSAG
4-10
9-12
53-60
Medium
V. High
4
4
Bahiagrass
WSPG
3-5
9-12
50-56
High
Medium
1
1
Bermudagrass (hybrid)
WSPG
5-8
10-14
55-60
V. High
V. High
1
1
Cool season annual grass (CSAG), cool season annual legume (CSAL), cool season perennial grass (CSPG), warm season annual grass (WSAG), and warm season perennial grass (WSPG).
Typical range in yields of recommended varieties, but highly dependent on growing season and conditions.
§ Assumes harvest or grazing occurs at recommended stages of growth.
Based on 2010 seed, fertilizer, and fuel costs and assuming moderate soil fertility.
†† Ratings are 1–4: 1 = relatively easy and 4 = quite difficult or requires high level of management.

Cool Season Annual Forage Programs

Figure 3. A typical seasonal yield distribution of selected cool season annual grasses in Georgia. Figure 3. A typical seasonal yield distribution of selected cool season annual grasses in Georgia.

Mild weather and the ability to grow high quality forages during late winter and spring make the cool season annual forage program an excellent option for forage-based stocker systems. In general, cool season annuals are high in crude protein and very digestible (Table 1). Cool season annual forage grasses and legumes can maintain high quality through the spring if the forage is kept in a vegetative stage of growth by proper grazing management. Research suggests that lightweight calves should gain an average of 1.8 to 2.3 pounds per day on productive, well-managed cool season annual pastures with little or no supplementation. The performance of cool season annual crops varies with location in the state, soil type, and management. However, it is generally useful to combine cool season annuals either individually in separate paddocks or as mixtures within a paddock. The primary reason for doing this is that the crops differ in when they are most productive and complement the forage quality of one another (Figure 3). Using two or more species, either in a mixture or in different areas, provides better distribution of forage production.

Cool Season Annual Forage Crops

Small Grains

Rye, wheat, and oats are widely used in stocker programs. Rye and wheat are more cold tolerant than oats and can be grown statewide. Oats are best adapted to south Georgia. Rye produces more forage in late fall and late winter than wheat but matures earlier in spring. Wheat will provide grazing about three weeks later in spring than rye. The growing season for oats is similar to wheat. Rye is the best choice for land that will be plowed in spring for a summer row crop because it matures in early spring. Wheat and oats are slightly more palatable than rye, and cattle generally gain slightly faster than when grazing pure stands of rye. Rye can mature very rapidly. As a result, the forage quality can decrease very quickly. Triticale (a hybrid of rye and wheat) can also be used, but it is not as grazing-tolerant and offers no substantive advantage over rye or wheat.

Annual Ryegrass

Annual ryegrass is a highly productive cool season annual grass with excellent forage quality. It is widely used in forage programs throughout the Southeast. In Georgia, ryegrass is more productive on heavier soils (those with a high clay or loam content or moist low-lying soils) than on deep well-drained sandy soils. Ryegrass is more productive in late spring than the small grains and will extend the spring grazing season. Ryegrass may be seeded in pure stands. However, it may be necessary to mix ryegrass with rye and/or an annual clover so that high-quality forage can be maintained from late winter through spring (Table 2).

Table 2. The effect of a cool season annual mixture on stocker production.
 
ORG
RG
RRG
TRG
WRG

ADG (lbs/hd/d) §

 

 

 

 

 

Winter 1.2 0.7 1.4 1.1 1.2
Spring 2.5 2.6 2.4 2.1 2.4
Gain (lb/acre)
253
239
281
219
256
Cost of Gain ($/lb)
$0.29
$0.28
$0.25
$0.39
$0.28
Net Return ($/acre)
$110
$106
$144
$56
$115
Adapted from Beck et al., 2007. J. Anim. Sci. 85:536-544 (SW Arkansas, Avg. of 2 yrs). Costs and returns based on actual values at the University of Arkansas’ Southwest Research and Education Center in 2002 and 2003.
ORG = oats + ryegrass; RG = ryegrass; RRG = rye + ryegrass; TRG = triticale + ryegrass; WRG = wheat + ryegrass.
§ Stockers weighed between 500 and 575 lbs. Note that the stocking rate in this study began at 1.5 stockers/acre and additional calves were later added to maintain equal grazing pressure on each treatment (a research method called “put-and-take”). In this study, grazing began in early winter (early January) and continued through early May in each system.

Cool Season Annual Clovers

Arrowleaf and crimson clover are cool season annual legumes adapted to well-drained, fertile soils in the Coastal Plain and Piedmont areas. These clovers are most productive in spring. Crimson matures earlier in spring than arrowleaf and provides less grazing in late spring. In the Piedmont, arrowleaf may provide grazing until early June.

Legumes are generally higher in protein and more digestible than cool season annual grasses, particularly as the grasses mature in late spring. As a result, gains of 2.5 lbs/head/day and 260 lbs/acre can be expected during spring grazing when an annual clover is used. In addition, these legumes may contribute as much as 100 lbs of nitrogen (N)/ acre via nitrogen fixation.

Management Considerations for Cool Season Annual Stocker Pastures

Detailed recommendations for managing cool season annual forages are covered more fully in other UGA Extension publications such as “Georgia Forages: Grass Species” and “Georgia Forages: Legume Species”. However, there are some slight variations on the recommendations for planting, fertilizing, and managing the grazing of cool season annuals that should be considered when they are to be used in a stocker development enterprise.

Planting

The first priority is to ensure that adequate forage is available when the grazing period needs to begin. The timing of forage availability is primarily affected by the cool season annual species (and, in some cases, variety) that is used, the type of seedbed into which the crops are to be planted, and the planting date. If late fall or early winter grazing is desired, rye or oats should be used (Figure 3). However, if peak forage availability is needed in the spring, annual ryegrass and wheat will generally provide more forage during those months. Crops planted into a prepared seedbed start quickly and provide grazing as early as late November in south Georgia or late December in north Georgia. However, to allow for the earliest possible grazing, the crop will need to be seeded as early as possible (early to mid-September in the Limestone Valley/Mountains region, mid- to late September in the Piedmont region, late September to early October in the Coastal Plain region).

If grazing in mid- to late winter is the goal, then cool season annuals can be planted into an existing warm season perennial grass sod. However, sod-seeded cool season annuals are slow-growing in the fall, and the forage is unlikely to achieve a sufficient height for grazing until late December or the end of January. Planting early may not allow for much earlier grazing when it is sod-seeded, and these early plantings may be slowed by the perennial grass or damaged by disease. When sod-seeding into perennial grass pastures, it is best to wait until growth of the perennial grass has been slowed by cool temperatures (mid-October).

Seeding rates can also affect the timing of forage availability in certain situations. When attempting to graze as early as possible, use a seeding rate that is on the high end of the recommended range, as this will generally provide more grazing earlier in the season (Table 3). Seeding rates higher than the recommended range are unlikely to provide any additional or earlier grazing and may increase the risk of disease. Late winter and spring forage yields are not influenced by seeding rates in the recommended range.

Table 3. Seeding rates and target planting dates for cool season annual forages.
Species
Seeding Rate*
Grown Alone
Mixture
lbs / acre
Ryegrass
25-30
15-25
Rye
90-120
60-90
Wheat
90-120
60-90
Oats
90-120
60-90
Triticale
90-120
60-90
Arrowleaf Clover
6-8
5-6
Crimson Clover
20-30
10-15
* Use higher seeding rates when broadcasting and lower rates when drilling into a prepared seedbed or existing sod (overseeding pasture).

Fertilization

A good fertilization program is necessary to produce high yields of high quality forage. Obtain a representative soil sample from each pasture and apply the recommended rates of phosphorus (P) and potassium (K) before planting. Amend the soil with lime to maintain soil pH above 6.0.

Small grain and ryegrass pastures can utilize up to 150 lbs of N/acre. Nitrogen fertilization is a key management tool to control forage growth. Adding N at the right time can increase tillering (thickening of the stand) and forage yield. Withholding N at certain times can help prevent the crop from growing too fast. Applying N at planting or soon thereafter is critical, since that initial 50 lbs of N per acre increases initial tillering and provides earlier grazing. A second application of N per acre should be applied in mid-January to early February to increase winter and spring forage production. If there is a great need for forage at that time and the coming weeks, 50 lbs of N per acre should be applied. If the need is less, decrease the N rate accordingly. If cool season annual legumes were used and they contribute 30 to 40 percent or more of the stand, then no more than 25 lbs of N per acre will be necessary in the winter application.

Because ryegrass is longer-lived, a third application of up to 50 lbs of N per acre may be needed in early spring when ryegrass is grown alone or used in a mix for late spring grazing, hay, or silage. If cool season annual legumes constitute 30 to 40 percent or more of the stand, then little if any additional N will be necessary in the spring. The key to remember is that ryegrass is very responsive to N. Take care to only apply enough N to meet the forage yield goal. Excess ryegrass forage, if it cannot be utilized, can be wasteful and pose risks to the grass crop that follows. This is especially problematic if the annual ryegrass is sod-seeded into bermudagrass, as late ryegrass production has been shown to decrease bermudagrass yields by 30 to 50 percent.

Grazing Management

Well-managed stands of cool season annual forages can provide excellent grazing. Grazing management can influence forage growth and utilization and animal performance. Limited grazing can begin in the fall as soon as the plants are well established and have 6 to 8 inches of accumulated growth. This ensures that root development is sufficient to prevent grazers from plucking the plant from the soil. Limited early grazing will improve tillering and increase stand density. However, it is critical that the pastures are not overgrazed during the early grazing period (i.e., maintain at least 2.5 to 3 inches of stubble height). This is also important in late winter when pastures start to recover from extreme cold. Allowing some regrowth to occur before putting significant grazing pressure on the pasture will significantly improve spring forage production.

Achieving the proper balance between cattle stocking rate and the forage growth rate is difficult. Forage growth varies during the growing season with changes in temperature and moisture conditions. The correct number of animals per acre in one week may be far too many the next week. To best utilize the forage that is grown, plan to provide supplemental feed and/or conserved forage during periods of slow pasture growth so that pastures will not be overgrazed.

Another way to prevent damage to late fall and winter pasture is to implement a rotational grazing program. Rotational grazing systems (sometimes called management-intensive grazing or MiG) allow the forage crop to recover more fully before being grazed again. Further, rotational grazing can substantially increase forage utilization efficiency (i.e., more of the forage that is produced ends up being consumed by the grazing animals) and this can increase the stocking rate that the forage system can sustain. More detailed information about the benefits of rotational grazing/ MiG and the steps necessary to develop an efficient grazing system can be found on the University of Georgia?s Management-Intensive Grazing website (www.caes.uga.edu/topics/sustainag/grazing/index.html).

Another strategy to more tightly control grazing is a method called “limit grazing.” Limit grazing is a system by which the animals are only allowed a brief opportunity to graze (usually one to two hours). Limit grazing works best when the cattle are allowed access at strategic times during the day. Cattle generally consume large quantities of forage in the morning (~6:00 to 8:30 a.m.) and mid-afternoon (3:00 to 5:00 p.m.) with a smaller bout around the time the sun sets. Timing a limit grazing bout to align with one or more of these natural grazing behaviors during a day can allow the animals to obtain much of their diet from the available pasture while minimizing hoof traffic and other damage to the stand. Of course, this assumes that one has another pasture or lot and enough conserved forage and feed for the animals when they are not present in the limit grazed pasture.

Regardless of the grazing system, it is important to measure how much forage is on offer, monitor the growth rate of the forage, and manage how much forage is allocated to the herd. The forage can easily be measured using a grazing stick or rising plate meter. This data can then be entered into a spreadsheet that can display the total forage in each pasture or paddock and the growth rate. More information on how to measure, monitor, and manage forage growth and allocation can be found on the University of Georgia?s Management-Intensive Grazing website on the page titled “Decision Support Tools for the 3 Ms of Grazing Management.”

Cool Season Perennial Forage Programs

The only cool season perennial forage systems recommended for use in stocker development in Georgia are those based on tall fescue. However, a large number of cool season perennial forage species can be used for stocker development in other parts of the U.S.

Tall Fescue as a Forage for Stocker Cattle

Figure 4. Forage distribution of tall fescue and the typical amount and timing of stockpiled tall fescue. Figure 4. Forage distribution of tall fescue and the typical amount and timing of stockpiled tall fescue.

Tall fescue is grown throughout the Piedmont and Mountain regions in Georgia. Tall fescue is best adapted to moist soils and is most productive in spring and fall, but it is dormant during July and August in Georgia. When adequate moisture is available, tall fescue will provide e

Status and Revision History
Published on Sep 30, 2011
Reviewed on Sep 25, 2014