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Dennis R. BuckmasterPurdue Agricultural & Biological Engineering

I’ll provide an internet URL for this entire presentation at the end.

Forage Systems OperationsStack

for storage

Wrap for storage

Pack into bag

Blow into silo

Pack into

bunker

Packaged transport

Bulk transport

Chop / roll process

Bale

Invert

Ted

Rake

Mow / condition

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What are the points (sources) of loss?� Pre-harvest� Machine

� Mower, rake, tedder, baler, chopper

� Respiration� Rain (leaching and longer respiration)� Storage

Types of Forage Loss� Dry Matter Loss … simply yield reduction� Quality Change … almost always drops (e.g., loss of leaves)

0

10

20

30

40

Dry

ma

tter

loss

(%

)

80 70 60 50 40 30 20 10

Average moisture content at harvest (%)

HARVEST LOSSSTORAGE LOSS

Directcut

silage(bunker,w/formic

acid)

Wiltedsilage

(bunker silo)

Haylage

(sealed silo)

Driedhay bales

Fieldcured hay

Rotz, 1991

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Presentation Outline

• Storage process determines suitable moisture range

Principles

• Mow• Swath manipulation• Bale• Store

• Inside• Not inside

Hay

• Mow• Harvest• Store

• Bunker• Bag• Bale• Tower

Silage

Forage Moisture Continuum12% 20% 30% 40% 70%

Safe

for

hay

Apply

preservative

or use a drier

Suitable for silage

Bunker

Tower

Baled

Silage

FIRE

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The principles• Low moisture so

respiration stops and bacteria, fungi, and yeasts cannot survive.

Hay

• Create anaerobic environment

• Reduce pH to a level where bacteria, fungi, and yeast growth is inhibited.

Silage

Basics of Silage Making

Pitt, 1990

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Basics of Silage Making

Pitt, 1990

Basics of Silage Making

Pitt, 1990

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Basics of Silage Making

Pitt, 1990

Typical Forage System Losses

Buckmaster, 1990

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Typical Forage System Losses

Buckmaster, 1990

Hay

Harvest

Storage

What can I do?

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Hay Harvest Losses

� Mowing-conditioning� 1-5%, mostly leaves� Conditioner design/setting has a large effect (trade-off

faster drying rate for more loss)� Flails cause more leaf loss in legumes

Hay Harvest Losses� Raking

� Loss increases as crop dries� Loss is higher with low yield or

after tedding� Loss can be up to 20%� Wheel & rotary rakes cause

more loss than parallel bar rakes� Best practice is to rake once, on

the day of baling

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Hay Harvest Losses� Baling

� Loss increases as crop dries� Loss occurs at the pickup

and in the chamber� Typical loss is 2 to 5%,

sometimes greater with low moisture or round balers in low yield situations (lots of tumbling)

� No large difference between in-line versus offset balers

Hay Harvest Losses� Respiration & Rain

� Highly variable� From 2 to 100% loss� Loss of most digestible plant

components

� Two strategies� Try to always avoid rain� Try to optimize annual harvest

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Hay Storage Losses

Huhnke

Quality deterioration can lead to 100% loss!

What can I do? … hay harvest� Time operations properly

� Mow considering crop and weather� Rake at 35-45% moisture or after rain� Ted immediately after mowing or after rain� Bale based on measured moisture content� Use preservative to avoid rain loss

� Have sufficient capacity (IN Hay Day 2008 topic)� Adjust machines appropriately� Operate at proper speeds� Take reasonable weather risks, then allocate ormarket

produced forages accordingly

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What can I do? … hay storage� Cover it� Keep it off of the ground

Buckmaster, 1993

Silage

Harvest

Storage

What can I do?

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Silage Harvest Losses� Mower-conditioner� Swath manipulation

� Rake� Merge

� Chop & transport

Silage Storage Losses� During filling� Long-term storage� During feedout

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Silage Storage … key factors� Proper moisture

� Too wet … effluent, clostridia risk� Too dry … lower density, inadequate moisture for

fermentation� Slow filling

� Longer respiration� Use of carbohydrate� Increase temperature

� Poor packing� Lower density (hence capacity)� More entrained air to consume� Less dense so infiltration is higher

What can I do? … silage & filling

BUNKER BAG TOWER BALED

Fill quickly Fill quickly Fill quickly Wrap soon

Fill in wedges or layers

Control stretch Even distribution in silo

Sufficient layers

Pack adequately Stack on end if atall

For all silage:•Proper moisture•Correct particle size•Adequate (high) density•Consider inoculants•Good initial quality

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125

188

250

313

375

20000

30000

40000

50000

60000

150 200 250 300 350 400 450

Min

imu

m b

un

ker

pac

ker

po

wer

(h

p)

Min

imu

m b

un

ker

pac

ker

wei

gh

t (l

b)

Harvester power (hp)

corn, 1 packer

haycrop, 1 packer

corn, 2 packers

haycrop, 2 packers

Adequate Bunker Packing

Buckmaster, 2009

At 160 lb/PTO hp

What can I do? ... silage longer term

BUNKER BAG TOWER BALED

Cover Keep seal, use proper tape

Maintain structure Keep seal, useproper tape

Contain effluent Adequate site Adequate site

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What can I do? ... silage feedout

BUNKER BAG TOWER BALED

Keep smooth face Control exposure Adequate removal rate

Open as you feed

Adequate removal rate

Feedout from a bunkerHolmes & Muck, 2000

>6 in/day removal rate>15 lb DM/ft3 density

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One more source of loss� Neither dry matter nor quality

� Of higher value than any forage you produce

� Let’s do our best to avoid …

Avoiding loss of life or limb� Shield disc mowers properly (knife tip speeds are

160 to 190 mph); always use a tractor with cab� Never stand behind conditioning rolls or flails� Remember that baler flywheels and hydraulic

accumulators store energy� Keep fingers out of moving knotters (even if they are

temporarily manually powered)� Do not ride the wagon when a bale thrower is used� Handle bales safely

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Avoiding loss of life or limb

� Keep equipment “harvest ready”� Keep guards & shields in proper order� Securely block hydraulically-raised

equipment before working around or under the machine

� Disengage power and shut off engine before unplugging

� Keep a fire extinguisher on all powered equipment

� No kids or other riders� Vent enclosed silage structures

A Useful Model -- IFSMThe Integrated Forage System Model

� Simulates multiple years, driven by historical weather data

� Growth models (grass, alfalfa, corn, small grains)� Harvest models (machinery, drying, operations, labor,

fuel, timing)� Storage models (hay, silage)� Feed utilization & conversion (beef, dairy, commercial

hay)

http://pswmru.arsup.psu.edu/software/ifsm.htm

The reference manual (free pdf) may provide you with

good insight regarding many forage processes.

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This presentation

For a limited time only …

http://cobweb.ecn.purdue.edu/~dbuckmas/icfs09/reducingloss.pdf