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Oat Hay Variety and Management Trial
R.L. Dovel, J. Rainey and G. Chllcote'
INTRODUCTION
Oat hay is of value in feeding both beef and dairy cattle. An
increasing acreage of oat hay is being produced in the Klamath Basin.
Little data has been collected on the relative hay yield potential of
various oat varieties in the Klamath Basin. Current varieties being
grown for oat bay are those also being grown for grain production. A
comprehensive variety trial examining the yield potential and quality
of currently available varieties is needed to provide producers with
a reasonable choice in selecting oat hay varieties.
Hay quality is affected both by variety and management. Management
has greater impact on forage quality than variety selection. Currently,
oat hay is generally cut at soft dough stage with the belief that getting some amount of grain production will increase quality. This has
not been found to be the case with other grass species. Delayed cutting
and advanced maturity tends to lower forage quality; however, forage
production does increase as the grass ages. This study was conducted
to examine the effect of time of cutting on oat hay quality and yield
and evaluate the relative yield potential of commercially available
bay varieties in the Klamath Basin.
MATERIALS OR PROCEDURES
Twenty-two oat varieties and two barley varieties were grown in a
variety trial. The trial was harvested at two distinct phenological
stages, at early boot and soft dough. Yield and acid detergent fiber
(ADF) were examined at both cutting dates.
The trial was established at the Klamath Experiment Station on fine
sandy loam soil that was moderately deep but somewhat poorly drained.
The plots were sprinkler irrigated on a weekly interval. The trial was
arranged in a randomized complete block design with four replications.
Seed was planted to the depth of 1 inch using a modified Kincaid plot
drill. Seeding rate was 100 lbs/A. All plots were fertilized with 50
lbs N, 30 lbs P 2 0 5 and 22 lbs S/A. Plots measured 5 x 20 feet with a
1/ Assistant Professor, Biological Sciences Research Technician and
Research Technician, respectively, Klamath Experiment Station.
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row spacing of 6 inches. One-half of each plot was harvested at boot
and soft dough growth stages. Growth stage was determined independently for each plot. Multiple harvests were made throughout the growing
season to insure harvesting each variety at the appropriate phenological stage. Area harvested measured 3 x 8.5 feet. Plot weights were
determined and sub-samples taken for lab analysis. Analyses included
measurements of (ADF) and crude protein (CP).
RESULTS AND DISCUSSION
Forage yields when harvested at early boot stage averaged 2.4 T/A
(Table 1). A significant difference existed between varieties. The
highest yielding varieties were Moore, Athabasca, Kanota, Cascade and
Winter Grey. The poorest yielding varieties when harvested at boot
stage were Benson, Whitford barley, Swan, Curt and Ogle. Yields were
substantially higher when harvested at soft dough stage, averaging 6.2
T/A. The higher yielding cultivars included Winter Grey, Montezuma,
Corbit and Stampede. Lower yielding oat varieties included Ogle and
Swan. Barley varieties included in this study yielded only 4.6 T/A when
harvested at soft dough stage. This was lower than any oat variety in
the trial.
Delaying harvest from boot stage to soft dough stage resulted in
loss of forage quality as reflected by higher ADF values. The average
ADF for oat varieties harvested at the boot stage was 34.1 percent while
the soft dough harvest resulted in ADF values of 39.5 percent. There
were significant differences in forage quality between varieties at both
harvest stages. Although quality decreased as harvest was delayed, ADF
values of the hay harvested at soft dough stage still remained at
acceptable levels to meet energy requirements for all but the most
demanding livestock classes (i.e. growing, finishing steer calves and
yearlings). Hay harvested at the boot stage was still not of sufficient
quality to meet the needs of these higher demanding livestock classes.
Hay harvested at the soft dough stage met the energy needs of pregnant
yearling heifers above 700 lbs., dry and lactating beef cows, and bulls
above 700 lbs.
Since forage quality of hay harvested at both boot and soft dough
is sufficient for similar livestock classes, comparison of total
digestible nutrients per acre is a valid comparison for forage value
produced. Harvesting at boot resulted in 3,134 lbs. of digestible
nutrients per acre. Harvesting at soft dough produced 7,576 lbs. of
digestible nutrients per acre. This is over twice the amount produced
at the boot stage and is a clear indication that best management practice for harvesting of oat hay is to cut at the soft dough stage, in
spite of a decline in quality. High yielding varieties that had very
low ADF at the soft dough stage included Sierra, which yielded 6.7 T/A
and had an ADF of 37.5 percent, and Kanota which yielded 6.7 T/A and had
an ADF of 37.7 percent.
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Table 1. Oat Hay Trial . Observations of the effects of variety
and stage of growth on forage yield and quality of 22
oat varieties and 2 hooded barley varieties at the
Klamath Exper iment Station in 1989.
Yield, tons/acre
Soft dough
Boot
Boot
ADF,
Soft dough
Variety
Species
1
2
3
4
5
Svea
Sierra
Cal Red
Cascade
Grey
0
0
0
0
0
2.3
2.4
2.8
2.8
3.0
6.3
6.7
6.8
5.5
8.2
32.4
33.6
40.2
32.9
36.8
41.8
37.5
41.6
37.5
42.6
6
7
8
9
10
Kanota
Benson
Porter
Otana
Park
0
0
0
0
0
3.1
1.4
2.1
2.3
2.6
6.7
5.3
5.7
6.5
6.8
30.4
35.4
33.0
33.6
34.3
37.7
37.6
41.1
40.8
39.4
11
12
13
14
15
Ogle
Montezuma
Curt
Cascade
Monida
0
0
0
0
0
1.6
2.9
1.6
3.0
2.8
4.9
7.9
5.4
6.3
5.9
33.7
35.3
33.4
34.7
35.4
40.5
40.4
39.8
38.3
39.7
16
17
18
19
20
Viking 765
Athabasca
Swan
Corbit
Moore
0
0
0
0
0
2.5
3.2
1.6
2.4
3.4
6.6
6.0
4.9
7.6
5.7
31.1
36.0
35.6
33.4
37.6
38.8
40.4
37.8
39.0
36.1
21
22
23
24
Stampede
Valley
Whitford
Westford
0
0
2.3
2.7
1.5
2.6
7.5
5.3
4.6
4.6
30.4
32.0
30.6
36.6
43.4
38.4
36.5
40.4
2.4
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1.1
6.2
19
1.7
34.1
5
2.6
39.5
5
2.8
Mean
CV(%)
LSD(0.05)
B
B