CCP Storage: Limiting Dry Matter and Quality Losses
from Harvest to Feedout
Everett D. Thomas
Oak Point Agronomics, Ltd.
Hammond, NY 13646
INTRODUCTION
Farmers pay a lot of attention to the crop inputs that influence yield and forage quality: variety and hybrid selection,
fertilization and pest control, and of course the equipment
needed to get the crop into the ground and then from field
to silo. Yield reductions in the field are obvious, both to
the farmer and to his farming neighbors, and to a lesser
extent so are the in-field quality losses due to delayed
harvest (hay crops) or inadequate nitrogen fertilization
(grasses, corn grown for whole-plant silage) Often much
less attention is paid to preserving quality and dry matter
retention from harvest to feedout, though these losses
can often be even more costly. For instance, a 10% dry
matter loss after the crop is harvested is worse than a
10% yield loss in the field because of the additional costs
involved in harvesting, transporting, and ensiling the crop.
This paper will highlight several of the management factors involved in preserving forage quality from the field
to the feedbunk.
SILAGE INOCULANTS
Bacterial silage inoculants should be considered as part
of a farm’s risk management strategy—a very economical
form of post-harvest “crop insurance.” A meta-analysis of
silage inoculant trials—all brands of inoculant, all types
of forage—found that silage inoculants “work”—their
use results in increased dry matter preservation and/or
increased milk production—about three-quarters of the
time. Milk production (where it was measured) increased
in about half the trials, with the average increase 2 pounds
per cow per day. Therefore, the overall response averaged
1 pound for all trials where milk production was measured. Assuming current milk prices and the typical cost
of a silage inoculant, a 1-pound milk response represents
a payback of at least several dollars of milk income per
dollar spent for a silage inoculant.
There are many companies selling bacterial silage inoculants as well as non-bacterial silage additives including
acids and enzymes. Some products are marketed as crop-
2014 Penn State Dairy Cattle Nutrition Workshop
specific while others are recommended for a wide range of
ensiled crops. In choosing a silage inoculant, consider the
type of crop that will be stored, the approximate moisture
content—some inoculants are more effective than others
when crops are ensiled at less than 30% DM—and feedout
procedures. There are thousands of strains of Lactobacillus
plantarum, the most common homofermentative silage
bacteria. Some are very effective, others not so much
so. The best silage inoculants contain the most effective
fermentation bacteria, often patented combinations of
homofermentative and heterofermentative species; that’s
what the farmer is paying for when purchasing an inoculant. Priority should be given to silage inoculants marketed
by companies that back their performance claims with
data, preferably from unbiased sources.
The physical form of inoculant—water-soluble product or
dry granules—can make a difference. Dry granules often
work well with corn ensiled as whole-plant silage since
the dry matter content of the forage is usually under 40%.
Granules need sufficient moisture before the fermentation bacteria are activated, while an inoculant in solution
is ready to start working right away. Preference should
be given to water-soluble products if there’s a reasonable chance that hay crops may be over 40% DM when
harvested. Using 53% DM alfalfa forage, Whiter and Kung
at the University of Delaware found that compared with
a water-soluble inoculant it took a granular inoculant
three times as long (15 days vs. 5 days after ensiling) for
the alfalfa to reach a pH of 4.5.
PACKING SILAGE IN BUNKER SILOS AND
DRIVE-OVER PILES
Packing forage into bunker silos and drive-over piles can be
as simple as a properly weighted tractor that’s also used for
other jobs on the farm, or as specialized as a self-propelled
“sheep’s foot” that has one primary use. Regardless of the
packing equipment used, the objective is the same: pack
relatively thin layers with enough weight to result in quick,
efficient fermentation. I’ve seen good jobs of packing using a steel culvert filled with concrete through which an
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axle had been inserted, a many-tired dump cart filled with
stones, a wide range of tractor sizes and tire configurations,
and the aforementioned sheep’s foot.
Speaking of tires, a commonly asked question is: which
does the best job of packing, singles or duals? The answer
is that it makes little difference. Research in Kansas, New
York, and Wisconsin all came to the same conclusion: no
difference in silage density or dry matter losses regardless
of whether the packing tractor had single tires or duals.
The important factors are packing tractor weight, thickness of the layer of forage packed, and total time spent
packing per ton of forage. A more practical factor on the
single vs. duals question arises when the farmer is packing
bunker silos where there’s a significant crown. The operator of a tractor packing a steep slope on a bunker silo with
10- or 12-foot sidewalls may very much appreciate the
additional stability provided by dual tires.
SILO PLASTICS
In evaluating silo plastics it’s all about the oxygen transmission rate (OTR). Lower numbers are better. This assumes
that the basics of covering silos have been met: a plastic
cover applied soon after the silo has been filled and packed,
sufficient overlap between sheets, and appropriate weighting of the plastic whether tires or gravel bags. Lower OTR
plastic is preferred because it results in better preservation
of the top several feet of silage. There are several types of
low-OTR plastic on the market, most of which are better
than “regular” two-ply silo plastic. The newest silo covers
have OTR that are up to 60 times less than standard silo
plastic. In addition to the OTR of the product, how tightly
it adheres to the surface of the silage is also important.
Better adherence means lower aerobic losses.
Some farmers use two layers of standard silo plastic.
While this results in lower spoilage losses, less surface
mold, and therefore more edible silage, two layers of
standard plastic aren’t nearly as good as a single layer
of low-OTR plastic. In one trial an extra layer of standard
silo plastic reduced the amount of inedible silage, but not
nearly as much as a single layer of a high-density, lowOTR cover. Of course, almost any cover is better than no
cover at all, a fact apparently (and remarkably) still not
recognized by some farmers.
interfering with each other. However, a proper drive-over
pile has sides that are no steeper than 3 to 1 (something
apparently lost on many, if not most, California dairies).
Packing tractors can drive on 3 to 1 slopes without loss
of traction. Drive-over piles with steep slopes can’t be
adequately packed, resulting in excessive aerobic losses.
An important note on silo safety: whether bunker silo or
drive-over pile, be careful when working anywhere near
the face of these silos. One suggestion is for people on
foot to not get any closer than three times the maximum
height of the silo. And the maximum height of the silo
should never be greater than the reach of the unloading
equipment; this will prevent silage overhangs and the
danger of a silage “avalanche.”
“IT’S IN THE BAG.”
OR BUNKER, PILE, OR UPRIGHT…
In recent years we’ve learned that corn silage isn’t a
stable forage for a considerable time after it is ensiled.
We may consider fermentation to be complete after the
silage has stopped heating and has reached a desired pH
level, but changes in the silage continue for some months
thereafter. What doesn’t change after the first few weeks
is NDF digestibility, but protein digestibility, starch digestibility, and silage acid content all change. Of these, the
changes in starch are the most important. Not only are
the changes predictable in that they routinely occur, but
they’re significant. Cumberland Valley Analytical Services
found that on September 22, after corn silage had been
stored for three weeks, the total acid content was 4.5%. By
February 16, after 24 weeks of storage, acid content had
increased to 7.5%. During this same time period, starch
digestibility increased from 70% to 77%. Farmers feeding a high rate of corn silage, unless they monitor starch
digestibility in their silage, would be feeding a somewhat
“hotter” ration by late winter or early spring than when
they first opened the silo. That’s why it’s important to
make a gradual change when switching from “old crop”
to “new crop” corn silage.
DRIVE-OVER PILES
Drive-over piles are the fastest growing form of silage storage in the U.S. They have flexible capacity, are relatively
inexpensive since there aren’t any concrete walls, and two
or more packing tractors can be used on the pile without
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November 12-13  Grantville, PA
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Limiting dry matter and quality losses
from harvest to feedout
Ev Thomas
Oak Point Agronomics, Hammond, NY
2
3
4
Silage inoculants
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2014 Penn State Dairy Cattle Nutrition Workshop
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Risks and rewards
Silage inoculant economics

A survey of inoculant trials including all types of silage
found that milk production increased in half of the trials.

Where production improved, the average daily increase
was 2 lbs. of milk per cow. So for all trials, 1 lb./cow.

Assume 50 lbs silage/cow/day = 40 “cow days” per ton.
40 x 1 = 40 pounds more milk per ton of silage.

How much does a farmer get paid for 40 lbs. of milk
milk?
?
What does it cost to inoculate a ton of forage?

Silage inoculants should be considered as part of a
dairy’s risk management strategy. It’s crop insurance.

Miner Institute inoculates every ton of ensiled forage,
every year, and has been doing so for over 30 years.

But there are lots of products out there: Which should
you use?

Start with a reputable company, one that backs its
performance claims with research data.
data.
Fermentation bacteria
The good, the bad and the ugly
Inoculant form:
Dry granules or soluble product?

There are thousands of strains of Lactobacillus
plantarum,, the primary homofermentative bacteria, as
plantarum
well as several other types of fermentation bacteria.

Either will work if there’s enough moisture in the
chopped forage.


These bacteria vary greatly in their effectiveness,
including how fast and how far they drop silage pH
during fermentation.
Inoculants applied in solution are ready to work right
away, while granules need sufficient moisture before
they become activated.

Seldom a problem with corn silage since it’s almost
always harvested at less than 40% DM.

Can be a problem with hay crop silages that are over
40% DM---delayed action.
The best silage inoculants contain the most effective
bacteria.
bacteria

Effect of inoculant form on ensiled
pH of 52% DM alfalfa
6.5
Packing silage
6
5.5
Control
Liquid
5
Granular
4.5
4
0
5
10
15
Days after ensiling
Whiter and Kung, 1998
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Duals vs. single tires

Research in NY, Wisconsin and Kansas found no
difference between singles and duals in silage density or
dry matter loss.

Important factors: Weight of packing tractor(s), packing
layer thickness, total packing time spent per ton of
silage.

However, when packing on silo slopes, especially on
over--filled bunker silos, duals may be preferred due to
over
tractor operator safety.
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Silo plastic makes a difference
Cover material
Standard white/black
SiloStop 2-Step clear
SiloStop 1-Step
white/black
High density plastic: 60 times
better OTR than standard black
plastic.
Thickness
5.0 mil
1.8 mil
4.5 mil
OTR
1811
30
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Michigan State University
However, the oxygen transmission rate of the plastic
doesn’t always predict how it will perform on the silo.
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2014 Penn State Dairy Cattle Nutrition Workshop
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Silo plastic economics
What about two layers
of standard 5-mil plastic?
Meta--analysis, 41 studies: 1.8 mil high density,
Meta
low OTR vs. standard 5 mil plastic

In top 2 feet of silage: 11% DM loss for 1.8 mil HD vs. 20 %
DM loss for 5 mil.

Overall DM savings from low OTR plastic (depending on silo
dimensions) 2.52.5-5%.
90’ x 210’ bunker silo: Net gain $4500$4500-9000.

2.52.5-5% reduction in spoilage loss is better than a 2.52.5-5%
increase in crop yield. Assuming 20 ton/A corn silage yield,
that’s better than a 0.5 - 1 ton increase in yield. Every year!
DM loss, %
Surface
mold, inches
Inedible
silage, %
Single layer
5 mil
Double layer
5 mil + 5 mil
Single layer
1.8 mil HD
14.4
6.0
12.5
3.7
7.4
<0.1
20.1
14.0
3.5
Silage density 37 lbs/cubic foot.
Storage time: 175 days
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A California stack silo.
Would you drive up and down these sides?
Near Sacramento, California.
Did they run out of tires…or ambition?
Note spoilage layer!
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Central Valley, California
A drive-over pile, done right.
This is a 2-to-1 slope, not 3-to-1
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Face management
20+ foot high silo, but the loader could
reach 14-15’ high. A recipe for disaster.
Silage facers:
Rakes vs. rotary cutters

Farmers claim that rakes are faster: One said he could
unload 44-5 times as much silage with a rake than with a
rotary cutter.

One trial found no meaningful temperature difference in
either haylage or corn silage.

Rotary cutters don’t have much effect on corn silage
particle size, but they do reduce haylage particle size.
Silage bags
Silage bags

Practical for many farm sizes.

Mold problems possible if grass silage is ensiled at
40+% DM . Silage density isn’t as high as in uprights,
bunker silos or drivedrive-over piles.

It still pays to inoculate forages in silage bags. Perhaps
not L. buchneri products though—
though—small feeding face.

Corn silage in bags can be a problem—
problem —pests! High
moisture corn in bags is even worse.
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2014 Penn State Dairy Cattle Nutrition Workshop
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Corn silage in silage bags

Birds quickly discover which silage bag(s) contain corn
silage, peck holes in them looking for the grain.

How to prevent “pecker hole” problems?

Get a couple of cans of black spray paint and paint a
squiggly line on top of any bag containing corn silage.

Birds apparently think it’s a big snake and avoid it—no
more damaged bags. Sounds crazy but it works.
Delay feeding new crop corn silage.
Corn silage is not stable!
Months in silo
2
4
6
Starch
digestibility, %
53
54
59
Protein
digestibility, %
39
36
34
8
10
64
69
43
47
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European research, 15 bunker silos
Corn silage digestibility,
3-week rolling average (CVAS)
Date
Storage week
7 hour starch
digestibility, %
30-hour NDF
digestibility, &
September
0
63
59
Sept. 22
(4.5% total acids)
3
70
61
Oct. 13
6
71
61
Nov. 3
9
72
61
Nov. 24
12
74
61
Dec. 15
15
76
60
Jan. 5
18
77
60
Jan. 26
21
76
61
Feb. 16
(7.5% total acids)
24
77
61
March 9
27
77 2012
Cumberland
Valley Analytical Services,
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Why does starch digestibility
increase in the silo?

Kernels soften as they imbibe moisture. “Juicing up.”
Kernels with no hard starch are more digestible.

Chemical changes are also happening to kernel starch.
Kernel Processing Score increases with time.

Acetic and lactic acid increase for 6 months after
ensiling—4.5% at week 3, 7.5% at week 24.
ensiling—

One high producing herd removed several pounds of
corn meal from the ration and milk production increased
increased..
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Making good silage is expensive

Using silage inoculants, proper packing, and high quality
silo plastic are all expensive and timetime-consuming.

Silo inoculants are frequently not used, particularly by
custom operators, and it’s a real pain to put on silo
plastic and weight it down properly.

To save time and input cost: Don’t do any of those
things: Just low it into a pile and simply take what you
get. But here’s what you’ll get:
Near Chazy, N.Y. Not Miner Institute!
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
75
70
65
60
55
50
1
2
3
4
29% DM
34% DM
41% DM
5
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2014 Penn State Dairy Cattle Nutrition Workshop
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