2. Drought-Stressed Corn:
Silage is an Option
• Drought-stressed corn that is unlikely to
resume growth should be ensiled.
• 85 to 100% of the normal net energy content.
• May contain more crude protein.
• May contain high nitrate concentrations,
especially in the lower third of the plant.
• Do not feed until at least 3 weeks after the
silo has been filled.
3. Corn Silage: Nitrate Caution
% Nitrate
(NO3) in Dry
Matter
Feeding Instructions
0.0 – 0.44%
Safe to feed.
0.44 – 0.88%
Limit to 50% of total dry ration for pregnant
animals.
0.88 – 1.50%
Limit to 25% of total dry ration.
Avoid feeding pregnant animals.
Over 1.50%
Toxic. Do not feed.
At high enough concentrations, nitrates are poisonous to cattle.
The ensiling process will decrease nitrates by 30 to 50%.
4. Corn Silage Harvesting
• Milk line is ½ to ¾ down the kernel.
• Leaves above the ear should be
mostly green.
• Dry matter content should be near
35%, slightly less for storage in
bunkers, trenches, or stacks.
• Silage should be chopped into
lengths of approximately 3/8 to 1/2
inch.
1/2
3/4
5. Corn Silage Storage
• Any structure that preserves the green and moist forage
in the absence of air and water.
• Silo
• Bunker
• Bags
6. Corn Silage Moisture:
Microwave Test
•
•
•
•
•
•
Collect a representative sample of fresh plants.
Chop the plants in 1 to 2 inch pieces.
Weight a sample (about 3 to 4 oz or 100 g)
Spread the sample uniformly and thinly over a microwave safe dish and
place in oven.
Heat for 1 to 2 minutes and weigh. Heat for 30 seconds and reweigh.
Repeat until two weight recordings are similar. If the sample chars, use
the previous weight.
Calculate the percent moisture.
[
% moisture =
fresh wt – final wt.
fresh wt
]
X 100
7. Corn Silage Moisture: Grab Test
Squeeze a handful of green chop as tightly as
possible for 90 seconds to make a forage ball.
Condition of forage ball
Approx. Dry Matter
Content
Holds shape and there is considerable free juice
Below 30%
Holds shape but very little free juice
25 to 30%
Falls apart slowly and there is no free juice
30 to 40%
Ball falls apart rapidly
Above 40%
8. Corn Silage: Production
• Planting Date
– April 1 to May 1 in western Kentucky
– April 15 to May 15 in eastern and central KY
– Soil temperatures should be above 50oF at a 2inch depth for 3 or 4 days
• Planting Depth
– 1 ½ - 2 inches (depending on moisture and
temp)
9. Corn Silage: Production
• Planting Population
– 24,000 to 30,000 seeds/acre
– increase of 2,000 seeds/acre over grain corn
• Row Width
– 30 inches
• Fertility
– Follow AGR-1: Lime and Fertilizer
Recommendations
10. Corn Silage vs. Grain Production
• Increase plant populations by about 2,000 seeds/A
compared to grain corn.
• Add more pounds of potash per acre compared to
grain corn (see AGR-1).
• Use a full- to late-season, high grain producing hybrid.
11. Silo Gases: Caution
• Lethal gases - greatest danger is between 12 to
72 hours after filling.
• Run the blower.
• Stay out of the silo for at least one week after
filling.
• Keep doors closed between silos and barns.
Any experience of the slightest throat irritation or
coughing requires immediate medical attention.
12. Nutrient Sampling for Feed Quality
• Collect a couple handfuls of each load of silage that
is being unloaded.
• Keep the samples out of sunlight.
• Mix the samples together.
• Keep refrigerated until sent off for analysis.
13. Silage Publications
• AGR-79: Producing corn for grain and silage
• ID-139: A comprehensive guide to corn
management
• AGR-1: Lime and fertilizer recommendations
• AEU-41: Temporary silage storage
• ID-86: Using drought-stressed corn: harvesting,
storage, feeding, pricing
14. Corn Hybrid Types
• Dual-Purpose
– Normal corn hybrids used for grain and/or silage
• NutriDense
– Slightly higher oil and protein content in the kernel
• Waxy
– 100% amylopectin (believed to be more digestible)
• Leafy
– Have more leaves above the ear than normal
hybrids
• BMR
– Lower lignin content than normal corn, making it
more digestible
15. No-Till Silage Project
• Four hybrids
–
–
–
–
Dual Purpose
Nutri-Dense
Waxy
Leafy
• Three Populations
– 22,000
– 27,500
– 33,000
• Two N Fertility
Levels
– AGR-1
– Yield Goal
16. Hybrid effect on yield
18
16
14
12
Dry Matter 10
(Mg/ha)
8
6
4
2
0
a
a
a
b
ES213ND
ES112
F2F797
8464wx
Hybrid
