Slide 1 Silage- Preserved Grass for Winter Feed. Factors That Affect Silage Quality Use of...
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Transcript of Slide 1 Silage- Preserved Grass for Winter Feed. Factors That Affect Silage Quality Use of...
Slide 1
Silage- Preserved
Grass for Winter
Feed
Factors That Affect Silage Quality
Use of additives Compaction Speed of filling &
sealing the pit Wetness when cut Time of year
ensiled
Silage DataHarvest Date
15 May 29 May
13 June
27 June
Silage Yield 4.0 5.2 6.6 7.8
Silage Digestibility
75 70 65 60
Silage Intake
9.0 8.3 7.6 7.0
Carcass Gain
0.51 0.39 0.27 0.15
Increase in yield= longer growing period, increase photosynthesis & day length,
Variation in digestibility= grass develops flower, high % cellulose, reduction in starch
Decrease in carcass = lower intake, less digestible food, decreased protein content
Making Silage Preserved grass by
acids. Lactic Acid from
sugars in grass Complete absence
of air. Adequate supply of
sugars.
Complete Absence of Air Air must be excluded to enable Lactic
Acid Bacteria to feed & prevents rotting. Lactobacilli Streptococci These bacteria feed & multiply to
produce LACTIC ACID-Preserve Anaerobic bacteria The Faster air is excluded the quicker
the bacteria can start to work on sugars to produce acid to lower pH.
Fast filling the pit & sealing is vital pH 4 as fast as possible
Adequate Supply of Sugars
Anaerobic bacteria feed sugars Acids
Sugar content 10 –15%
Different grass species Grass acts as a
substrate for the bacteria & converts the sugars to acids
Grass Species used for Silage
Perennial Ryegrass Italian Ryegrass
(biennial) White clover Red clover
Factors forming Lactic Acid Silage
Air free Fill silo quickly Short cut grass Good compaction Wilted grass Lactobacillus Streptococcus
Good Acidification Low pH Effective Additive Good Sealing of
silo High sugar Grass STAGE of Growth= High Palatability,
High Digestibility
Additive Improve Silage
Preservation Increased Silage
Intake Improved
digestibility & animal performance
Molasses Sugar Based Added to supplement sugars already
present in grass. The sugars are converted to acids by
microbes. 9-18 litres/ton of grass Added either by harvester or at the pit Young leafy grass, wet weather have
reduced sugar content
Sulphuric/Formic Acid These reduce the pH of
grass from 6 to 4.8 Creates an environment
which favours lactic acid production
2-3 litres/ton The lower the sugar level
in grass, the leafier the grass & the wetter the grass the higher rate of acid is used
Silage Cutting Mower- chops the
grass up small to increase the surface area for bacteria to act on
Precision chop mower
Wilting This is to cut the grass & leave it on the
ground for 24 –48 hours before gathering up & ensiling it
To remove some water from the crop Increases conc. Of sugars Reduces level of effluent Raises DM content Reduces the activity of undesirable
bacteria Reduces the size of clamp required Saves on additives
To Make silage1. Close the field in time.2. Fertilize adequately3. Cut at the correct stage of growth- precision chopper4. Allow to wilt for 1-2 days5. Pick up the grass6. Transport to pit/bale7. Fill pit quickly8. Use an additive9. Spread grass and compact evenly10. Cover & seal the pit
Experiments % Sugar in silage sample Compare silage samples-colour, smell,
pH, water content. % DMD To conserve grass as silage in the lab
Veronica Walsh, Coláiste Treasa
To get high levels of carbohydrates Cut the grass at the young leafy stage Cut in dry conditions(water dilutes) Allow to wilt Cut using a precision chop mower Use a carbohydrate rich additive Mow in afternoon