World Dairy Expo
Options for Harvesting Corn Stover for Supplemental Feed
Kevin Shinners
University of Wisconsin
World Dairy Expo
• Why consider corn stover :
High feed costs
Abundant – 10 million tons in WI
Relatively low cost
High in effective fiber
Reduces residue
Introduction
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• Important issues with corn stover :
How to harvest, store and feed
Cost
Right feed additives
Introduction
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• How corn stover can be used :
Effective fiber source @ 2 – 5% of dietary DM
Feed for non-lactating and beef animals
Bedding
Biomass feedstock
Introduction
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• What are stover yields?
Rough rule of thumb:
1 : 1 ratio with grain weight
Every 35 bu ~ 1 ton stover
140 bu/ac ~ 4 ton/ac
Introduction
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Dry Bale Harvesting
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Dry Stack Harvesting
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• Issues with bale and stacker systems:
Slow field drying :
Low ambient temps, short day length
Short harvesting window
Frequent weather delays
Dry Stover Issues
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15%
30%
45%
60%
75%
90%
26-Aug 2-Sep 9-Sep 16-Sep 23-Sep 30-Sep 7-Oct 14-Oct
Moi
stur
e .
.. %
w.b
.
Grain
Stover
Stover Moisture
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Stover Drying
10%
20%
30%
40%
50%
2-Oct 4-Oct 6-Oct 8-Oct 10-Oct
Moi
stur
e .
.. %
w.b
.
0
2
4
6
8
10
12
Rainfall .. m
m
Untreated
Flat
Single Windrow
Double Windrow
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Stover Drying
10%
20%
30%
40%
50%
60%
10-Oct 12-Oct 14-Oct 16-Oct 18-Oct 20-Oct
Moi
stur
e .
.. %
w.b
.
0
2
4
6
8
10
12
Rainfall .. m
m
UntreatedFlatSingle WindrowDouble Windrow
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• Issues with bale and stacker systems:
Low productivity
Low density package
High ash content
Dry Stover Issues
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~6
~10
LRB
~3
~5
Stack
Density
~8lb. / ft3
LSB
~16tons / h
Productivity
Dry Stover Harvesting
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Dry Bale Harvesting
Ash .. % of DM
Baled
Standing
7.9
3.5
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• Issues with bale and stacker systems:
High storage losses
Non-uniform product
Dry Stover Issues
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Outdoor Storage of Bales
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14%20%Plastic Twine
Outdoors on Soil
37%
11%
2%
Wet Year
34%
29%
11%
5%
Dry Year
Stacks
Sisal Twine
Net Wrap
Indoors
Storage Losses
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Non-Uniformity of Bales
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Wet Stover Harvesting -Chopping
Chopped Wet Stover
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• Advantages of harvesting stover wet:
Eliminates field drying
Harvest right behind combine
Reduced soil contamination
Higher productivity
Easier to mix additives
Harvesting Wet Stover
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9 – 16
20 – 80
Typical WPCS
8 – 10Silo Density … lb. / ft3
Corn Stover
25 – 35Productivity … tons / h
Chopped Wet Stover
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Chopped Wet Stover
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0.6%0.9%1 – 3%Acetic
3.3%
4.1
3.8%
55%
Corn Stover
1.7%
4.5
1.4%
42%
5 – 10%
3.8 – 4.2
6 – 10%
60 – 65%
Typical WPCS
Lactic
DM Loss
pH
Acids
Moisture
Chopped Wet Stover
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Stover Particle Size
¾ – 1
8 – 10
Particle – Size .. in.
Round Bales and Stacks
Chopped
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Baled Wet Stover
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Baled Wet Stover
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2.3%0.5%Acetic
0.8%
4.4
2.9%
44%
Early
0.4%
5.1
1.2%
29%
Late
Lactic
DM Loss
pH
Acids
Moisture
Baled Wet Stover
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• Compared to dry systems, wet stover offers:
Less weather concerns
More uniform product
Easier mixing & feeding
Fewer storage losses
Potentially lower costs
Wet Stover Systems
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Stover Costs
$9Bales – Outdoors
$14
$14
$14
$28
Approximate cost per dry ton
Storage
Bales – Indoors
Round Bales
Chopped
Chopped – Bag
Harvest
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• How stover is fed :
Free-choice from bales or pasture
Sorting
Ground
TMR
Feeding Stover
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Stover Fractions
Stalk – 58% Leaf – 19%
Cob – 12%
Husk – 8%
After Grain Harvest / Before Stover Harvest
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Dry Bale Harvesting
Stalk – 49%Leaf – 36%
Cob – 3%Husk – 10%
After Stover Harvest
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76.3
46.7
4.0
7.7
Baled
3.8CP
41.9ADF
68.2
–
Chopped
NDF
Ash
After Storage Composition
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• To improve protein and digestible energy :
Wet and dry distillers grains
Grain
Whole-plant corn silage
Ammonia
Stover Feed Additives
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43.0
25.2
8.3
7.0
Stover + Corn*
70.2
45.0
8.3
12.3
Stover
14.4 CP
30.0ADF
57.5
8.4
Stover + DDG*
NDF
Ash
Feeding Stover
* - 50% of dietAfter Summer and Trenkle - 1998
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53.7
6.7
Stover + Corn*
39.1
5.7
Stover
59.4Digestibility .. %
6.4
Stover + DDG*
Intake .. lb. / day
Feeding Stover
* - 50% of dietAfter Summer and Trenkle - 1998
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Future of Stover Harvest
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Future of Stover Harvest
Cob, husk & leaf
Grain
Ear Snapper Head
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Future of Stover Harvest
All stover: Stalk, cob, husk & leaf
Grain
Whole-plant Head
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Future of Stover Harvest
World Dairy Expo
Options for Harvesting Corn Stover for Supplemental Feed
Kevin Shinners
University of Wisconsin