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Experiments to Determine the Effects of Spring Chaparral Treatment on Forage Characteristics and
Beef Steer Performance in Missouri
©Dr. Kevin Bradley, University of Missouri
Materials and Methods
• 12, 2.5 acre paddocks; 6 E+, 6 E-
• April 1: 2 ozs Chaparral + 1 qt 2,4-D sprayed on 3 E+ and 3 E-paddocks; 1 qt 2,4-D sprayed on remaining 3 E+ and 3 E-paddocks
• Forage harvests conducted monthly from April – July
Sprayed with 2 ozs Chaparral + 1 qt 2,4-D/A on April 1, Photo Taken May 5
©Dr. Kevin Bradley, University of Missouri
Sprayed with 1 qt 2,4-D/A on April 1, Photo Taken May 5
©Dr. Kevin Bradley, University of Missouri
Influence of Spring Chaparral Application on Total Forage Yields from April - July (Columbia, MO 2010)
0
500
1,000
1,500
2,000
2,500
3,000
3,500
April 13 May 19 June 10 July 9
Yie
ld (
lb/A
)
Harvest Date
1 qt 2,4-D
2 oz Chaparral + 1 qt 2,4-D
© Drs. Sexten, Bradley, and Roberts, Univ. of Missouri
735 a
1846 a
3687a3350 a
540 b
878 b
1600 b 1556 b
*Means within harvest dates followed by the same letter are not different, P<0.05.
Harvest Dates
Herbicide
Treatment
Endoph.
Level April 13 May 19 June 10 July 9
--- Ergovaline + Ergovalinine (ppm)a ---
2,4-D EsterE- 1.83 a 0.18 b 0.08 c 0.02 b
E+ 1.32 a 0.71 a 0.54 b 0.29 a
Aminopyralid+
Metsulfuron+
2,4-D Ester
E- 0.9 a 0.07 b 0.04 c 0.03 b
E+ 1.06 a 0.73 a 0.76 a 0.26 a
a Means within a column followed by the same letter are not different, P<0.05.
© Drs. Sexten, Bradley, and Roberts, Univ. of Missouri
Harvest Dates
Herbicide Trtmt April 13 May 19 June 10 July 9
-------------- Crude Protein (%)a -------------
2,4-D Ester 26.0 a 12.1 b 9.2 b 8.8 b
Aminopyralid +
Metsulfuron +
2,4-D Ester
21.6 b 12.7 a 10.7 a 10.3 a
aMeans within a column followed by the same letter are not different, P<0.05.
© Drs. Sexten, Bradley, and Roberts, Univ. of Missouri
Harvest Dates
Herbicide Trtmt April 13 May 19 June 10 July 9
------------------- ADF (%)a ------------------
2,4-D Ester 28.9 a 36.1 a 39.4 a 40.8 a
Aminopyralid +
Metsulfuron +
2,4-D Ester
30.6 a 35.1 b 37.7 a 36.7 a
aMeans within a column followed by the same letter are not different, P<0.05.
© Drs. Sexten, Bradley, and Roberts, Univ. of Missouri
Harvest Dates
Herbicide Trtmt April 13 May 19 June 10 July 9
------------------- NDF (%)a ------------------
2,4-D Ester 51.9 a 62.7 a 65.3 a 67.5 a
Aminopyralid +
Metsulfuron +
2,4-D Ester
52.2 a 61.5 b 63.2 a 65.5 a
aMeans within a column followed by the same letter are not different, P<0.05.
© Drs. Sexten, Bradley, and Roberts, Univ. of Missouri
Influence of Spring Chaparral Application on Forage Grass Seedheads at the July Harvest (Columbia, MO 2010)
0
50
100
150
200
250
300
Tall Fescue Orchardgrass KY Bluegrass Smooth Brome
See
dh
ead
s (#
/m2)
Forage Grasses
1 qt 2,4-D
2 oz Chaparral + 1 qt 2,4-D
282 a
111 b
6 a21 a
83 a
60 a
6 a 4 a
© Drs. Sexten, Bradley, and Roberts, Univ. of Missouri
*Means within harvest dates followed by the same letter are not different, P<0.05.
Influence of Endophyte Level and Chaparral Treatment on Steer Performance (Columbia, MO 2010)
Control Chaparral P =
Item E- E+ E- E+ SEMa Trtb Endoc Trt x End
Initial wt, lbsd 475.4 469.4 486.1 488.6 10.6 0.19 0.87 0.69
Final wt, lbs 658.3 621.9 639.7 646.8 16.5 0.85 0.38 0.21
ADG, lbs /day 2.24 1.83 2.15 2.08 0.12 0.47 0.07 0.18
Grazing days 82.0 84.0 71.3 76.0 1.3 < 0.001 0.03 0.34
Slick hair, %e 53.3 63.2 56.6 93.2 0.08 0.03 0.13
a Largest standard error of least squared means
b Broadleaf weed control method
c Pasture endophyte presence
d Two day full weight at pasture turnout
e Percent of cattle exhibiting slick hair coat
© Drs. Sexten, Bradley, and Roberts, Univ. of Missouri
Influence of Spring Chaparral Application on Steer Serum Prolactin (Columbia, MO 2010)
27
16
21
28
2524
0
5
10
15
20
25
30
May 11 June 8 July 7
Seru
m P
rola
ctin
, ng
/ m
l
Sample date
1 qt 2,4-D 2 oz Chaparral + 1 qt 2,4-D
* Treatment P < 0.05
*
© Drs. Sexten, Bradley, and Roberts, Univ. of Missouri
Influence of Endophyte Infection Level on Steer Serum Prolactin (Columbia, MO 2010)
34
28
26
22
13
20
0
5
10
15
20
25
30
35
40
May 11 June 8 July 7
Seru
m P
rola
ctin
, ng
/ m
l
Sample date
E- E+
* **
* Endophyte Level P < 0.05 © Drs. Sexten, Bradley, and Roberts, Univ. of Missouri
Influence of Spring Chaparral Application on Tall Fescue and Grass Weed Density in September (Columbia, MO 2010)
0
10
20
30
40
50
60
Tall Fescue Yellow Foxtail Large Crabgrass Other Grass Weeds
De
nsi
ty (
#/m
2)
Species
1 qt 2,4-D
2 oz Chaparral + 1 qt 2,4-D
© Drs. Sexten, Bradley, and Roberts, Univ. of Missouri
*Means within harvest dates followed by the same letter are not different, P<0.05.
57 a
13 b
5 b 1 b
33 b
37 a
26 a
14 a
Spring Treatment:
2,4-D Only
Spring Treatment:
Chaparral + 2,4-D
Picture Taken on Sept. 9 ©Dr. Kevin Bradley, University of Missouri
Picture Taken on Sept. 9
Spring Treatment:
Chaparral + 2,4-D
Spring Treatment:
2,4-D Only
©Dr. Kevin Bradley,
Univ. of Missouri
©Dr. Kevin Bradley, University of Missouri
Spring Trtmt. of 1 qt 2,4-D/A
Picture Taken Sept. 9
©Dr. Kevin Bradley, University of Missouri
Spring Trtmt. of 2 ozs
Chaparral + 1 qt 2,4-D/A
Picture Taken Sept. 9
©Dr. Kevin Bradley, University of Missouri