Extension circular 87-115 is about breeding and management improves quality of switchgrass pasture

Anderson, Bruce E.

Vogel, Ken

Ward, John

English

DigitalCommons@University of Nebraska

University of Nebraska - LincolnDigitalCommons@University of Nebraska - LincolnHistorical Materials from University of Nebraska-Lincoln Extension Extension1987EC87-115 Breeding and Management ImproveQuality of Switchgrass PastureBruce E. AndersonUniversity of Nebraska-Lincoln, banderson1@unl.eduKen VogelUniversity of Nebraska-Lincoln, Ken.Vogel@ars.usda.govJohn WardFollow this and additional works at: http://digitalcommons.unl.edu/extensionhistThis Article is brought to you for free and open access by the Extension at DigitalCommons@University of Nebraska - Lincoln. It has been accepted forinclusion in Historical Materials from University of Nebraska-Lincoln Extension by an authorized administrator of DigitalCommons@University ofNebraska - Lincoln.Anderson, Bruce E.; Vogel, Ken; and Ward, John, "EC87-115 Breeding and Management Improve Quality of Switchgrass Pasture"(1987). Historical Materials from University of Nebraska-Lincoln Extension. 4625.http://digitalcommons.unl.edu/extensionhist/4625ftGt-1 5 25 t7 University of Nebraska Cooperative Extension Service EC 87-115 Institute of Agriculture and Natural Resources r~PR 1 ~; i987 Breeding and Management Improve Quality of Switchgrass Pasture By Bruce Anderson, Ken Vogel, and John Ward Reprinted from BETTER CROPS with PLANT FOOD Spring 1985 Potash & Phosphate Institute 2801 Buford Hwy. , N.E. Suite 401 Atlanta, GA 30329 a Issued in furtherance of Cooperative Extension work , Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture . Leo E. Lucas, Director of Cooperative Extension Service , University of Nebraska , Institute of Agriculture and Natural Resources . The Cooperative Extension Service provides information and educational programs to all people without regard to race, color , national origin . sex or handicap . ~0 •• •• l • . .. ~ ~ ' ' I • ... ~.~ • • <>~ Breeding and Management Improve Quality of Switchgrass Pasture By Bruce Anderson, Ken Vogel, and John Ward LIVESTOCK PRODUCERS north and east of the central Great Plains rely on cool-season grasses like smooth brome, orchardgrass, tall fescue, and timothy for pasture. Cool-season grass-es can be highly productive and nutritious during spring and fall , but during sum-mer they are less productive and low in quality. Switchgrass is an erect, warm-season perennial grass native to this area. When switchgrass pastures are grazed during summer and cool-season grass pastures are grazed during spring and fall, livestock gains are higher than when cool-season grasses are grazed during the en-tire grazing season (Table 1). Table 1. Dally gain Of lielfers during summer fOI· lowing spring grazing of tall fescue at Mt. Vernon, MO. Grass ADG Tall fescue 0.92 Swltchgrass 1.21 Matches et al. 1!175-78. SWC ReL Rep, UMC Historically, switchgrass has been difficult to establish because of slow seed-ling growth and weed competition. Today, switchgrass can be established in one growing season when atrazine herbicide is used to control weed growth (Table 2). Although using switchgrass for mid-summer grazing will improve cattle gains, the digestibility of switchgrass is lower than that of cool-season grasses harvest-ed at similar stages of maturity. Digesti-bility measures the energy value of a grass, and the more digestible grasses usually produce faster rates of gain. In 1973, a study was initiated in eastern Nebraska to improve switchgrass digest-ibility by plant breeding. Over 2,000 switchgrass plants that were similar in maturity and origin to 'Pathfinder' switchgrass were established in a selection nursery. Each of these plants had digest-ibility measured using a test-tube tech-nique called in vitro dry matter disappearance (IVDMD). This technique uses rumen fluid collected from cattle to digest a sample of forage. Twenty-five healthy, vigorous plants were identified that had high digestibility. Another 25 vigorous plants with low IVDMD also were identified to help grass breeders es-timate the genetic variability of digesti-bility in switchgrass. After the high and low IVDMD plants were identified, both Table 2. Stands and forage yields of swltchgrass seeded In 1978 at Mead, NE. 1978 1979 Forage Forage Atrazlne Yield Yield Stand ·····-··lbiA········· ··················tons/A·················· o/o 0 0 4.0 65 0 + handweeded 3.9 5.2 90 1 2.7 6.0 97 2 2.4 5.0 94 Marlin et al. 1982. Agronomy Journal 74:916·920 Dr. Anderson is Extension Forage Specialist and Dr. Vogel is Research Geneticist, USDA/ARS, in the Depart-ment o f Agronomy, and Dr. Ward is P rofessor in the Department of Animal Science at the University of Nebraska-Lincoln. Table 3. Forage y1elds and d1gestiti11ity of ttiree swltchgrass hays seeded at Mead, NE in 1978. ~ 1978 Strains Yield IVDMD tons/A Dfo High IVDMD 3.3 47.2 Pathfinder 3.2 45.6 Low IVDMD 3.3 43.3 Vogel et al. 1984. Crop Science 24:977·980 groups were moved to separate, isolated fields where seed was produced. In 1978, seed produced from these iso-lated switchgrass fields and from Path-finder were seeded in small plots (Figure 1). From 1978 through 1980, the IVDMD of the high IVDMD, Pathfinder, and low IVDMD strains averaged 50.6, 47.7, and 46.70Jo, respectively. The strains did not differ appreciably in forage yield (Table 3). Switchgrass responds well to nitrogen fertilizer (Table 4) so these high yields were obtained by applying lOOlb ofN/A. Soil tests showed no P was needed in that particular study. However, switchgrass does respond to P applied on low P soils Means 1979 1980 Yield IVDMD Yield IVDMD tons/A Dfo tons/A 0/o 4.1 55.8 5.6 48.9 4.0 54.0 5.2 43.6 4.1 52.8 5.6 44.1 (Table 4). On low P soils, switchgrass uses N fer-tilizer more efficiently when P require-ments are met. Table 4. Annual yield of swltchgrass fertilized with N and/or P in Dixon County, NE. p N Aj!j!lied {lb/A} Aj!j!lled 0 40 80 120 lb/A ··················tons/A·················· 0 1.58 1.60 1.93 1.90 20 1.33 2.17 3.12 3.46 40 1.35 2.18 2.98 3.63 Rehm, 1981. Soli Sci. Res. Rep, UNL Figure 1. Switchgrass plots. (continued on next page) Replicated one-acre pastures were seed-ed to these three strains in 1981. To speed establishment, 2 lb active ingredient of atrazine/ acre was applied preemerge. In 1982 and 1983, pastures were burned in early spring and 2lb of atrazine were ap-plied to reduce weed invasion. Each year 100 lb ofN as ammonium nitrate/acre was applied in May. Pastures were grazed by three beef yearlings/ pasture for 69 and 62 days, respectively, in 1982 and 1983 (Figure 2). Heifers were used in 1982 and steers in 1983. Yearlings grazing the high IVDMD strain gained 0.4 lb/ day more than yearlings grazing Pathfinder and produced nearly 80 lb more beef per acre each year (Table 5). At 60 cents/ lb, this would mean an additional $48 annual profit per acre. Gains during 1983 were much higher than in 1982. In 1982, yearling heifers began grazing when switchgrass was 32 inches tall and were unable to consume it as rapidly as new growth occurred, allowing many seed-heads to develop. In 1983, yearling steers began grazing when switchgrass was 12 inches tall and consumed it at nearly the same rate as growth occurred. No seed-heads developed during grazing. This il-lustrates the importance of grazing management practices that provide livestock with less mature, more digesti-ble forage. Conclusion These results demonstrate that switch-grass is a highly productive warm-season grass for hay production or summer graz-ing. A small improvement in IVDMD produced a large increase in livestock gains. The high IVDMD strain has been released as the new cultivar 'Trailblazer', and switchgrass quality might be im-proved even more with additional breed-ing and improved forage management. Certified seed should be available for planting in the spring of 1986. Breeding for improved forage quality in other grasses may also improve gains of livestock grazing these grasses. • Table 5. Average forage digestibility and performance of beef yearlings grazing switchgrass strains at Mead, NE. 1982 1983 1982-83 Avg. Strain IVDMD ADG Gain/A IVDMD ADG Gain/A ADG Gain/A Dfo ......... Jb-········ 0/o ·······················lb······················· High IVDMD 49.4 1.0 210 63.7 2.2 402 1.6 306 Pathfinder 47.2 0.6 128 62.0 1.8 327 1.2 227 Low IVDMD 48.0 0.9 186 61.3 1.7 311 1.3 255 Ward et al. 1984. Journal of Animal Science 59 (Supplement1):303 (abstract 385). Figure 2. Beef yearlings grazing. 

EC87-115  Breeding and Management Improve Quality of Switchgrass Pasture

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University of Nebraska - Lincoln
DigitalCommons@University of Nebraska - Lincoln
Historical Materials from University of Nebraska-
Lincoln Extension Extension
1987
EC87-115 Breeding and Management Improve
Quality of Switchgrass Pasture
Bruce E. Anderson
University of Nebraska-Lincoln, banderson1@unl.edu
Ken Vogel
University of Nebraska-Lincoln, Ken.Vogel@ars.usda.gov
John Ward
Follow this and additional works at: http://digitalcommons.unl.edu/extensionhist
This Article is brought to you for free and open access by the Extension at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for
inclusion in Historical Materials from University of Nebraska-Lincoln Extension by an authorized administrator of DigitalCommons@University of
Nebraska - Lincoln.
Anderson, Bruce E.; Vogel, Ken; and Ward, John, "EC87-115 Breeding and Management Improve Quality of Switchgrass Pasture"
(1987). Historical Materials from University of Nebraska-Lincoln Extension. 4625.
http://digitalcommons.unl.edu/extensionhist/4625
ftGt-1 
5 
25 
t7 
University of Nebraska Cooperative Extension Service EC 87-115 
Institute of Agriculture and Natural Resources 
r~PR 1 ~; i987 
Breeding and Management Improve 
Quality of Switchgrass Pasture 
By Bruce Anderson, Ken Vogel, and John Ward 
Reprinted from 
BETTER CROPS with PLANT FOOD 
Spring 1985 
Potash & Phosphate Institute 
2801 Buford Hwy. , N.E. 
Suite 401 
Atlanta, GA 30329 
a Issued in furtherance of Cooperative Extension work , Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture . Leo E. Lucas, Director of 
Cooperative Extension Service , University of Nebraska , 
Institute of Agriculture and Natural Resources . 
The Cooperative Extension Service provides information 
and educational programs to all people without regard 
to race, color , national origin . sex or handicap . 
~0 •• •• l • . .. ~ ~ ' ' I 
• ... ~.~ • • <>~ 
Breeding and Management Improve 
Quality of Switchgrass Pasture 
By Bruce Anderson, Ken Vogel, and John Ward 
LIVESTOCK PRODUCERS north 
and east of the central Great Plains rely 
on cool-season grasses like smooth 
brome, orchardgrass, tall fescue, and 
timothy for pasture. Cool-season grass-
es can be highly productive and nutritious 
during spring and fall , but during sum-
mer they are less productive and low in 
quality. 
Switchgrass is an erect, warm-season 
perennial grass native to this area. When 
switchgrass pastures are grazed during 
summer and cool-season grass pastures 
are grazed during spring and fall, 
livestock gains are higher than when cool-
season grasses are grazed during the en-
tire grazing season (Table 1). 
Table 1. Dally gain Of lielfers during summer fOI· 
lowing spring grazing of tall fescue at 
Mt. Vernon, MO. 
Grass ADG 
Tall fescue 0.92 
Swltchgrass 1.21 
Matches et al. 1!175-78. SWC ReL Rep, UMC 
Historically, switchgrass has been 
difficult to establish because of slow seed-
ling growth and weed competition. Today, 
switchgrass can be established in one 
growing season when atrazine herbicide 
is used to control weed growth (Table 2). 
Although using switchgrass for mid-
summer grazing will improve cattle gains, 
the digestibility of switchgrass is lower 
than that of cool-season grasses harvest-
ed at similar stages of maturity. Digesti-
bility measures the energy value of a grass, 
and the more digestible grasses usually 
produce faster rates of gain. 
In 1973, a study was initiated in eastern 
Nebraska to improve switchgrass digest-
ibility by plant breeding. Over 2,000 
switchgrass plants that were similar in 
maturity and origin to 'Pathfinder' 
switchgrass were established in a selection 
nursery. Each of these plants had digest-
ibility measured using a test-tube tech-
nique called in vitro dry matter 
disappearance (IVDMD). This technique 
uses rumen fluid collected from cattle to 
digest a sample of forage. Twenty-five 
healthy, vigorous plants were identified 
that had high digestibility. Another 25 
vigorous plants with low IVDMD also 
were identified to help grass breeders es-
timate the genetic variability of digesti-
bility in switchgrass. After the high and 
low IVDMD plants were identified, both 
Table 2. Stands and forage yields of swltchgrass seeded In 1978 at Mead, NE. 
1978 1979 
Forage Forage 
Atrazlne Yield Yield Stand 
·····-··lbiA········· ··················tons/A·················· o/o 
0 0 4.0 65 
0 + handweeded 3.9 5.2 90 
1 2.7 6.0 97 
2 2.4 5.0 94 
Marlin et al. 1982. Agronomy Journal 74:916·920 
Dr. Anderson is Extension Forage Specialist and Dr. Vogel is Research Geneticist, USDA/ARS, in the Depart-
ment o f Agronomy, and Dr. Ward is P rofessor in the Department of Animal Science at the University of 
Nebraska-Lincoln. 
Table 3. Forage y1elds and d1gestiti11ity of ttiree swltchgrass hays seeded at Mead, NE in 1978. 
~ 
1978 
Strains Yield IVDMD 
tons/A Dfo 
High IVDMD 3.3 47.2 
Pathfinder 3.2 45.6 
Low IVDMD 3.3 43.3 
Vogel et al. 1984. Crop Science 24:977·980 
groups were moved to separate, isolated 
fields where seed was produced. 
In 1978, seed produced from these iso-
lated switchgrass fields and from Path-
finder were seeded in small plots (Figure 
1). From 1978 through 1980, the IVDMD 
of the high IVDMD, Pathfinder, and low 
IVDMD strains averaged 50.6, 47.7, and 
46.70Jo, respectively. The strains did not 
differ appreciably in forage yield (Table 
3). Switchgrass responds well to nitrogen 
fertilizer (Table 4) so these high yields 
were obtained by applying lOOlb ofN/A. 
Soil tests showed no P was needed in that 
particular study. However, switchgrass 
does respond to P applied on low P soils 
Means 
1979 1980 
Yield IVDMD Yield IVDMD 
tons/A Dfo tons/A 0/o 
4.1 55.8 5.6 48.9 
4.0 54.0 5.2 43.6 
4.1 52.8 5.6 44.1 
(Table 4). 
On low P soils, switchgrass uses N fer-
tilizer more efficiently when P require-
ments are met. 
Table 4. Annual yield of swltchgrass fertilized 
with N and/or P in Dixon County, NE. 
p N Aj!j!lied {lb/A} 
Aj!j!lled 0 40 80 120 
lb/A ··················tons/A·················· 
0 1.58 1.60 1.93 1.90 
20 1.33 2.17 3.12 3.46 
40 1.35 2.18 2.98 3.63 
Rehm, 1981. Soli Sci. Res. Rep, UNL 
Figure 1. Switchgrass plots. 
(continued on next page) 
Replicated one-acre pastures were seed-
ed to these three strains in 1981. To speed 
establishment, 2 lb active ingredient of 
atrazine/ acre was applied preemerge. In 
1982 and 1983, pastures were burned in 
early spring and 2lb of atrazine were ap-
plied to reduce weed invasion. Each year 
100 lb ofN as ammonium nitrate/acre was 
applied in May. Pastures were grazed by 
three beef yearlings/ pasture for 69 and 62 
days, respectively, in 1982 and 1983 
(Figure 2). Heifers were used in 1982 and 
steers in 1983. 
Yearlings grazing the high IVDMD 
strain gained 0.4 lb/ day more than 
yearlings grazing Pathfinder and 
produced nearly 80 lb more beef per acre 
each year (Table 5). At 60 cents/ lb, this 
would mean an additional $48 annual 
profit per acre. Gains during 1983 were 
much higher than in 1982. In 1982, 
yearling heifers began grazing when 
switchgrass was 32 inches tall and were 
unable to consume it as rapidly as new 
growth occurred, allowing many seed-
heads to develop. In 1983, yearling steers 
began grazing when switchgrass was 12 
inches tall and consumed it at nearly the 
same rate as growth occurred. No seed-
heads developed during grazing. This il-
lustrates the importance of grazing 
management practices that provide 
livestock with less mature, more digesti-
ble forage. 
Conclusion 
These results demonstrate that switch-
grass is a highly productive warm-season 
grass for hay production or summer graz-
ing. A small improvement in IVDMD 
produced a large increase in livestock 
gains. The high IVDMD strain has been 
released as the new cultivar 'Trailblazer', 
and switchgrass quality might be im-
proved even more with additional breed-
ing and improved forage management. 
Certified seed should be available for 
planting in the spring of 1986. 
Breeding for improved forage quality 
in other grasses may also improve gains 
of livestock grazing these grasses. • 
Table 5. Average forage digestibility and performance of beef yearlings grazing switchgrass strains 
at Mead, NE. 
1982 1983 1982-83 Avg. 
Strain IVDMD ADG Gain/A IVDMD ADG Gain/A ADG Gain/A 
Dfo ......... Jb-········ 0/o ·······················lb······················· 
High IVDMD 49.4 1.0 210 63.7 2.2 402 1.6 306 
Pathfinder 47.2 0.6 128 62.0 1.8 327 1.2 227 
Low IVDMD 48.0 0.9 186 61.3 1.7 311 1.3 255 
Ward et al. 1984. Journal of Animal Science 59 (Supplement1):303 (abstract 385). 
Figure 2. Beef yearlings grazing. 


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EC87-115 Breeding and Management Improve Quality of Switchgrass Pasture

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