Penn State Cooperative Extension
Capitol Region Dairy Team
TESTING SILAGES
Tim Beck
Capitol Region Extension
Dairy Program Coordinator
Silage harvest will begin soon
in some areas. It’s time to be
thinking about how you’ll evalu
ate the nutritional value of this
year’s crop.
Forage testing is absolutely es
sential to provide a balanced ra
tion for the dairy herd. But be
yond the basic tests available,
there are many other options to
consider using when special cir
cumstances arise.
Drought conditions in some lo
cations make it worth consid
ering a nitrate test so that cutting
height may be adjusted upward
where high nitrates may be pres
ent in the crop. During times
when rainfall is abundant, it’s
helpful to check the sugar con
tent of the crop, since heavily
eared corn is less likely to have
soluble sugars present in the
leaves and stalk as they have
been used to produce grain.
Many labs offer a standard
analysis package that will assess
dry matter, crude protein, protein
fractions, acid and neutral deter
gent fiber, and many of the
macro and trace minerals. Fre
quently producers conduct the
Corn Silage Whole-Plant Dry Down Rates*
Glenn A. Shirk, Extension Dairy Agent, Lancaster, Pa.
Looks can be deceiving. This week, the better looking com planted
on May 1 was drier than the more severely fired com planted on the
same date. It appears that the droughty com was less functional and
matured more slowly than the healthier com, as evidenced by milk
line progression, and tended to retain more of its moisture than
healthier plants that were more active and maturing more naturally.
This May 1 planting is now dropping below the desired moisture
levels for proper ensiling.
Estimating plant dry down by the amount of firing can be deceptive.
Even though the dryer com showed about 60% firing, the weight of
the dry leaves represents only a small part of the plant’s total weight
and is not necessarily indicative of the amount of moisture that is
retained in the stalk
This week a later planted sample of the same hybrid is added to the
table This com looks good. It is tall, green and well eared.
Whole , Predicted Days
Moisture Kernel Plant Plant t to Harvest 0
Test Milk Moist Sol ■ Firing Bunker | Tower
___Date___Line____^_ i^= Su£ar ß^^^^^^^do^^^ilo^
110-day corn planted May 1. Well eared and good ear fill:
Aug 4 None 73.5 , 33 5 13
Aug 14 1/4 73.3 133 I 5 [l3
Aug 21 1/3 69.5 i 33 | -1 I 7
Aug 28 1/2 , 63.8 . 40 -10 -2
Same hybrid and field, but droughty, small ears, 75% ear fill:
Aug 4 None 73.5 , 150 j 5 !13
Aug 14 1/4 , 72.8 50 ‘ 4 12
Aug 21 1/4 69.3 ' ' 50 ! -1 ! 7
Aug 28 ■ 1/3 , 65.0 ; 60 1 -8 I 0
Same hybrid planted May 25. Well eared and good ear fill:
Aug 28 None /6 0 9 ' 17
Footnotes
i-Conclucted at the Penn State Field Research Farm at Landisville.
)-Percent of stalk fired from the ground upward
-Based on 0 65 drop in % moisture from last test date
1-Based on a target moisture of 70% for bunker silos at harvest time.
-Based on a target moisture of 65% for tower silos at harvest time.
Tim Beck
standard set of forage tests, bal
ance accordingly, and still en
counter poor cow performance.
Many issues may be involved,
but frequently poor digestibility
of forage crops and overestimat
ed energy values are part of the
problem. Fiber digestibility varies
from year to year based on how
much fiber is bound to lignin and
therefore is indigestible to the
cow.
Just knowing how much lignin
is present doesn’t tell the story.
We must use procedures such as
in vitro (in test tube) digestibility
SRBC Urges Voluntary Water Conservation
HARRISBURG (Dauphin
Co.) - In support of the Pennsyl
vania Department of Environ
mental Protection’s (DEP)
drought watch declaration for
Central Pennsylvania, the Sus
quehanna River Basin Commis
sion (SRBC) is calling on water
users to conserve water. DEP’s
current drought watch declara
tion covers 23 Central Pennsylva
nia counties, all of which are lo
cated entirely or partially in the
Susquehanna River Basin:
analysis to get a picture of how
much fiber can actually be di
gested in a given forage sample.
During in vitro testing, forage
samples are incubated in rumen
fluid under controlled conditions
and the amount of fiber disap
pearance is measured.
Today’s more sophisticated
rumen modeling programs, such
as the Cornell Net Carbohydrate
and Protein System (CNCPS)
and the latest NRC for Dairy
Cattle, attempt to estimate the
energy value of forages more ac
curately. To use CNCPS correct
ly, a producer must request some
additional testing. Neutral deter
gent insoluble nitrogen (NDIN)
and acid detergent insoluble ni
trogen (ADIN) must be included
in the testing regime to use these
tools effectively.
Some labs offer a CNCPS
package that provides the addi
tional data. Kather than just
using book values for energy,
these programs calculate the en
ergy value of forages based on
more extensive test results than
those used in previous ration bal
ancing approaches.
Enzymatic starch and sugar
tests may be used to more accu
rately assess the “true” nonstruc
tural carbohydrate (NSC) present
in a given diet. This can help the
nutritionist assess and select sup
plemental energy sources in the
diet to achieve a balance of fast,
medium, and slowly digested car
bohydrates.
When forages have elevated
pH readings after fermentation
or they have strong or unusual
odors, consider a fermentation
profile on the samples to assess
now the forage fermented. The
fermentation acids may help you
identify what went wrong during
the preservation process so the
producer can make appropriate
corrections for the next crop.
Having soluble sugar checked be
fore and after fermentation may
tell a producer the odds for an
undesirable fermentation in ad
vance and just how much sugar
remains in the forage when pres
ervation is complete. When sug
ars are depleted during fermenta
tion, the resulting forage has
reduced energy value and must
be supplemented appropriately.
Many of these testing options
will require interpretation by a
skilled nutritionist to properly in
terpret and apply the information
to a dairy ration, but producers
are encouraged to discuss these
options with the herd’s nutrition
ist. The dollars invested in some
additional testing may return
themselves many times over
when “just the right combina
tion” of ingredients can be identi
fied.
More information on this topic
may be found in the publication.
Agronomy Facts 44, “Forage
Quality Testing: Why, How, And
Where,” available from the local
extension office or download a
copy at http://
www.agronomy.psu.edu/
Extension/Facts/AgFacts.html To
select a forage testing laboratoiy,
refer to DAS 99-18, “Animal di
agnostic, forage, and feed testing
laboratories in the Northeast”
available at http://
www3.das.psu.edu/dcn/catforg/
index.html
For additional information,
contact Tim Beck at (717)
840-7408 or e-mail tbcck@psu.e
du.
Adams, Bedford, Blair, Centre,
Clinton, Columbia, Cumberland,
Dauphin, Franklin, Fulton,
Huntingdon, Juniata, Lancaster,
Lebanon, Lycoming, Mifflin,
Montour, Northumberland,
Perry, Schuylkill, Snyder, Union
and York.
SRBC Executive Director Paul
Swartz noted that the entire Sus
quehanna basin has experienced
below normal precipitation in 11
of the past 13 months. March and
June of 2001 are the only months
when above normal precipitation
was recorded.
“This extended period of below
normal precipitation has resulted
in ground-water levels dropping
below normal, streams flowing
well below normal throughout
the basin, and very dry soil con
ditions,” said Swartz. “Each day,
more and more streams in New
York and Pennsylvania are drop
ping to record daily low flows
and the list of communities im
posing water restrictions or bans
on burning has begun to grow.”
Swartz said, “The drought in
dicators have clearly been
reached and so the Commission
strongly endorses DEP’s drought
watch declaration. We urge
water users to voluntarily con
serve water to help reduce the
stresses on public water supplies
and individual wells.”
Water conservation tips for
residential water users include:
• Not watering established
lawns (grass goes dormant
does not die during dry condi
tions);
• Sweeping sidewalks and
driveways, not hosing them
down;
• Selecting more drought-tol-
Trust Unveils New
Preserved Farm Sign,
Kicks Off Harvest Appeal
LANCASTER (Lancaster Co.) - Tuesday this week
brought the unveiling of the Lancaster Farmland Trust’s
new preserved farm sign. The signs, designed by Russ
Cox of Smiling Otis Designs, will highlight the commit
ment of farmers to the Trust. Twenty farmers who have
preserved through the Trust have already enthusiastically
agreed to have the signs placed on their farms. At the un
veiling were, from left, Amos Funk (seated), founder of
Funks Farm Market, first Ag Preserve Board president,
leader of agricultural preservation in Lancaster County;
Debbie Schattgen, assistant to the executive director,
The Lancaster County Foundation; James B. Sabino, ex
ecutive director, The Lancaster County Foundation; Gene
Garber, former mejor league baseball pitcher, first farmer
to preserve farms through LFT, current Ag Preserve
Board president; Tom Stauffer, Lancaster Farmland Trust
president: and John Moose, vice president of the agricul
tural banking division at Fulton Bank. Moose chairs the
Trust’s fall 2001 Harvest Appeal to help Lancaster Farm
land Trust achieve their goal of $225,000.
erant vegetation and plant spe
cies for landscaping and using
mulch to retain soil moisture;
• Taking short showers in
stead of baths;
• Using dishwashers and
washing machines only when
filled to capacity;
• Not letting the water run
continuously while shaving,
brushing teeth or washing dishes
by hand;
• Inspecting and repairing all
leaking faucets, pipes, hoses and
toilets; and
• Installing water conserva
tion devices.
Water conservation tips for
industrial/commercial facilities
include:
• Inspecting plumbing fixtures
for leaks and repairing all faulty
piping;
• Installing water conserva
tion devices and updating outdat
ed plumbing fixtures;
• Implementing a water re-use
program; and
• Installing best available
water conservation technology.
For more water conservation
tips and for SRBC’s most recent
Hydrologic Conditions report,
look on SRBC’s Website
www.srbc.net.
The Susquehanna River Basin
Commission is the governing
agency established under a
100-year compact signed on Dec.
24, 1970 by the federal govern
ment and the states of New York,
Pennsylvania and Maryland to
protect and wisely manage the
water resources of the Susque
hanna River Basin. The Susque
hanna River starts in Coopers
town, N.Y. and flows 444 miles to
Havre de Grace, Md., where the
river meets the Chesapeake Bay.