A Comparison of Higher-Moisture
vs. Lower-Moisture Ensiling
by Dr. Donald A. Sapienza, Research
Biochemist, Microbial Genetics Division,
Pioneer Hi-Bred International, Inc.
iSilage makers are sometimes
tempted to avoid problems such as
excess seepage, spoilage or undesir
able odor by ensiling crops at mois
ture levels of 60% or less. Although
this may prevent some problems, it
can cause others resulting in less
than-optimum recovery of dry matter
and nutrients from the silo at feeding.
There are several specific advan
tages to ensiling crops at higher mois
ture within the range of 63-68%.
(This range applies to conventional
upright silos measuring approx
imately 14 ft. in diameter and 50 ft. in
height. The moisture range for
bunker or pit silos would be higher;
the range for sealed structures would
be lower.)
1. Lower Field Losses
Field losses for corn harvested for sil
age at 65% moisture average only 4%.
However, losses increase to 16% when
the moisture level at harvest falls
below 60% . a These increased losses
are due mainly to leaf and ear drop
and downed stalks.
Field losses for hay crops harvested
for silage are only about 2% at 70%
moisture, but increase to 8% at the
55% moisture level. b Dropped and
shattered leaves account for most of
the increased loss, meaning that a sig
nificant amount of valuable protein is
left in the field.
2. Less Heat Damage
Ensiling dryer forage increases the
difficulty of packing the silo well, and
may result in less air being excluded.
Increased air penetration can encour
age mold growth and result in higher
fermentation temperatures. Ensiling
dryer forage can also cause higher
temperatures when the silage is fed
out. Aerobic stability or bunk-life
studies measuring temperature rise
and dry matter loss of silages during
aerobic exposure at feeding show
about a 3% loss in dry matter with
each 10° rise in temperature.
Ensiling temperatures greater than
100°F can also reduce protein avail
ability to animals. Although high fer
mentation temperatures can produce
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a pleasingly sweet, tobacco-like
aroma, the resulting 'carmelized’ sil
age is usually lower in feed quality.
Ensiling at 65% moisture allows for
better packing, reduced overheating,
recovery of more dry matter and
increased protein availability.
3. More Digestible Dry Matter
The comparative chart below helps
disprove the once popular belief that
the only thing higher-moisture silage
offers over lower-moisture silage is
more water. Generally speaking, the
percentage of digestible dry matter in
corn silage ensiled at 65%-70% mois
ture is approximately ten percent
greater than the same crop ensiled at
55% moisture.
Per Acre
Comparisons
Green Wt., lbs. 40,000
Dry Matter Pro
duced, lbs.
Tbtal Loss
(Estimated har
vest & storage
losses)
Feedable Dry
Matter, lbs. 9,960
% Digestibility 63%
Digestible Dry
Matter, lbs
The more efficient fermentation
obtained by ensiling at higher mois
ture also reduces the chances of refer
mentation, overheating and yeast and
mold growth when the silage is re
exposed to air.
Silage Moisture
70% 57%
30,000
12,900
22%
12,000
17%
10,062
57%
5,735
6,275
Lancaster Farming, Saturday, April 14,
4. Reduced Weather Risk
Weather can also play an important
part in the ensiling process. Tbo much
rain or sun can rob silage crops of val
uable nutrients. By ensiling at higher
moisture, the silage maker can reduce
the chances of bad weather causing a
reduction in feed value. This is partic
ularly true with hay crops cut for
silage.
Silage makers can take advantage
of the benefits of higher-moisture
ensiling while avoiding the draw
backs by using Pioneer® brand
1177 silage inoculant. 1177 contains
specially selected strains of lactic
acid-producing bacteria which bring
about a rapid, efficient homolactic fer
mentation in the silo. This modified
fermentation helps reduce the prob
lems of seepage, spoilage and over
heating which are often associated
with higher-moisture silages. A
homolactic fermentation also results
in more efficient conversion of plant
sugars to acids. These acids can be
used directly by the ruminant animal
for conversion to meat or milk.
By using 1177, the silage maker
can also reduce weather risk. Corn
can be harvested for silage earlier in
the season, when plants are closer to
their nutritional peak. And using
1177 on alfalfa harvested at higher
moisture makes same-day harvesting
practical (on a good drying day), and
minimizes the risk of overnight rain
damage to cut alfalfa.
‘S.A. Dum, R.S. Adams, J.E. Baylor &
A.R. Grout, "Silage & Silos,” Penn
State University special circular
223.
’Timothy Logan & Donald Hillman,
1975, "Preserve the energy and pro
tein of forages,” Michigan State Uni
versity extension bulletin E-803.
One in a series of articles devoted
to improved silage making and
sponsored by Pioneer Hi-Bred
International, Inc. 1177 silage
inoculant is available from your
Pioneer sales representative. Ask
him for more information about it.
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