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Lecture 13 Forage Conservation

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Need for conservation

  Feeding during drought or floods
  Utilizing surplus forage
  Transport of feed
Methods of Conservation

  Hay
  Silage
  Haylage

 Grasses are cut at optimum growth stage
 Left in the field to dry
 Machine used to turn over grass to aid
  drying (tedder)
 Dried grass swept in rows (windrow)
 Hay baler used to compress dried grass
  – cubes or big round bales
 Can also be used to conserve rice straw
Big bale hay
Padi straw hay
Problems with making hay

  Need plenty of sunshine – 3 consecutive
   days without rain
  Easily spoilt by moulds if not quickly dried
  Requires heavy investment in machinery
  Large storage area is required
  Can be a fire hazard

  Forage that is baled at a higher moisture
   content than dry hay and then stored in a
   sealed plastic wrap.
  Because of the high moisture level and
   air-tight environment, the forage ferments
   and is preserved by acid production
   during fermentation.
Advantages of Haylage
  Decreased curing time needed from cutting to
   baling makes weather less of a factor in forage
  Potential for more timely harvest of large
   quantities of forage.
  Decreased need for mechanical handling and
   time curing to dry the forage reduces the loss
   of leaves, the most digestible part of the plant.
  Potential for higher feed quality bale through
   leaf preservation and possible nitrate
Disadvantages of haylage
  Increased harvest cost per bale vs.
   conventional cured hay.
  Disposal of used plastic wrap.
  More likely to spoil as compared to silage in
   traditional silos.
  Risk of forage spoilage if integrity of wrap is not
   maintained. Birds and rodents can puncture
   plastic and holes must be covered.
  Transportation of bales is limited due to cost of
   moving high-moisture bales.
Advantages of silage

    More palatable than hay
    Not dependent on weather
    Can be kept longer without deterioration
    Not easily inflammable
    Requires less storage area
How haylage is made

  The forage is cut as if for haymaking, but
   is baled at 50 to 60% moisture rather
   than at 18-20% moisture.
Mechanised Silage Making
     Principle of Silage
 Forages are conserved in an
  environment of low pH (4.2) and
  anaerobic conditions where biochemical
  processes and activities of decomposing
  aerobic bacteria and fungi are inhibited
Materials which can be
   Grasses
   Sorghum
   Maize
   Oil palm fronds
   Crop byproducts (pineapple skin, cocoa
Factors required for good
   Airtight – to provide anaerobic conditions
   Moisture content in forage 65-75%
   Adequate soluble carbohydrates (>3%)
   Compaction of materials to exclude air
   Not contaminated with foreign matter e.g.
Silage making process

  Grass is cut at
   optimum growth
  Grass chopped up
Silage making process (2)

  Chopped grass filled in silo:
       Bunker silo
       Pit silo
       Tower silo
       Container
  Chopped grass compressed to exclude air
  Silo is sealed airtight
  Left for at least 21 days to complete ensilation
Tower Silo
Phases of fermentation
Baled silage
Baled Silage in N.Z.

Baled Silage
The Silager

  An invention in Institut Haiwan Kluang
  Able to mechanically compress silage in
   a bin
Mechanical press



Forage chopped

  Entry for fresh fodder
Phase I

  Grass is put in silo
  Respiration
  Oxygen is used up
  CO2 and heat is
  Temperature rises
Phase 2

  Acetic acid is
  pH declines from 6.0
   to 4.2
Phase 3

  Lactic acid is
  Acetic acid declines
Phase 4

  Lactic acid
   production continues
  Temperature
  Bacterial activity
   stops at pH 4.0
Characteristics of Good
    pH < 4.5
    Lactic acid 3 -13%
    Butyric acid < 0.2%
    Colour: yellowish to brownish green
    Odour: sweet smelling (vinegar smell)
    Wetness – no seepage
    Palatability – readily accepted by animals
    Nutritive value – almost similar to original
Additional steps for
making good silage
  Chop the material to allow easy
  Use additives: corn, soybean, molasses
   to increase soluble carbohydrates and
   protein (esp. if < 3% soluble
  Use enzymes to aid fermentation
Silage additives

 A. Stimulants aid in the growth of the lactic
  acid bacteria and the production of their
  acids so as to reduce silage pH at a
  faster rate.
Silage additives

 B. Inhibitors help to slow down unwanted
  silage degradation. For example,
  inhibitors may reduce mold growth or
  reduce the breakdown of plant proteins.
Silage additives

 Bacterial Inoculants are the main type of
  silage additive used in the U.S (about
  70% of all additives).
 They contain inactive bacteria that become
  active once they are put on the wet
Silage additives

  Sugars such as molasses, glucose, and
   dextrose can be added to forage to
   increase the lactic acid content of the
   silage by supplying more food (sugar) for
   the lactic acid bacteria to grow on.
Silage additives

  Enzymes are proteins that speed up the
   break down of plant carbohydrates to
  Common sources of enzymes include,
   Aspergillus oryzae, Aspergillus niger, and
   Bacillus subtillus.

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