Mahatma Jyotiba Fule College Of Veterinary Science And Animal Husbandry Chomu (R.J.)

Silage Principle, Properties and Types

PRESENTED BY:

Dr. Anil Kumar Patidar

2020-21

Assistant professor

DEPARTMENT OF LIVESTOCK PRODUCTION MANAGEMENT

COLLEGE OF VETERINARY SCIENCE & ANIMAL HUSBANDRY,

CHOMU (R.J.)

Silage

• Silage is the green material produced by controlled fermentation of the green fodder crops retaining the high moisture (60-65%) content.

HOW TO DO THAT ?

• Based on acidification due to lactic acid fermentation under anaerobic condition.

• It is known as pickle of green fodder.

ADVANTAGES OF SILAGE MAKING

Silage can be prepared from green fodder when the weather does not permit for hay making.

Silage can be prepared from plants having thick stems and highly palatable and slightly laxative.

Weeds can also be utilized along with main fodder crops for silage making. Silage making kills majority of weed seeds.

The organic acids produced in the silage are similar to those normally produced in the digestive tract of the ruminants.

Retains higher proportion of nutrients than hay because losses due to shatteringand bleaching are minimized.

Silage preserves 85% of feed energy.

It requires less storage space than hay.

It preserve protein and carotene better than hay.

Ensiling ensures better storage for long time.

Mechanisation from field cutting to feeding is easier with silage.

Many by-products can be economically used.

Crops can be preserved as silage more cheap, with less labour

Disadvantages Of Silage Making

• Requires silos and special equipment's.

• Less amount of Vit . D is present in silage compared to hay.

• Additional expenditure are involved for preservative like molasses.

• Due to moisture content, weight and transporting charges are increased.

• Smell from poorly fermented silages can be foul.

• Wastage percentage can be high when only small amounts are made at one time.

Selection Of Crops For Silage Making

High level of fermentable sugar.

Low level of protein.

Should have about 35 per cent dry matter at the time of ensiling.

Pasture grasses: Napier grass, Guinea grass, Sudan grass etc.

Pasture legumes: Stylo.

Fodder tree: Leucaena.

Straws: rice straw, wheat straw, soybean chaff, peanut hulls, etc.

Silage can be made from all winter and summer fodders.

But usually Maize, Oats, Sorghum etc. are considered best for silage making.

Normally fodder with Broad leaves and Thick stems.

Leguminous fodder has less carbohydrates and protein content, they are usually mixed with non leguminous fodder (like maize and sorghum) to make the best and nutritious silage.

PRINCIPLE OF SILAGE MAKING

• ANAEROBIC CONDITION is first and foremost requirement for silage making, as it allows lactic acid bacteria to grow, which converts sugars into lactic acid, a strong organic acid.

• As pH declines, the degrading actions of plant enzymes and undesirable bacteria are inhibited and at pH 3-4, most degrading enzymes are inhibited and the growth of lactic acid bacteria is also inhibited.

• In simple words the principle of silage is the same as that in making pickles.

Anaerobic Fermentation Of Soluble Sugar

↓lactic acid producing bacteria

Production Of Organic Acids

(1.5% LA + 0.5% AA + 0.1% BA)

↓

Acid produced reduces the pH up to 3 - 4

↓

Acidity inhibits further fermentation

↓

silage is ready

Procedure Of Silage Making• Select mature crop with carbohydrate or sugar content and low or little moisture.

• Cut the crop from the field

• Wilt the crop after cutting

• Chop the crop into small pieces

• Transfer the chopped crops into silo

• Crush /press the material with a roller

• Exclude air from silage

• Add additive like sugar, molasses.

• Pack the material into silo.

• Provide shelter over the silo to avoid seepage of rain water.

• Seal the silo pit airtight with plastic cover.

• Plastic covers should be pressed with heavy objects like bricks or tire.

• Maintain sealing for 45 days.

• Once silo-pit will be open, it should be finished within 45-60 days to avoid

fungal contamination.

Bacterial Changes During Ensilage

Phase 1 Phase 2 Phase 3 Phase 4 Phase 5

1.Grass is put in silo

2.Respiration continues

3.Oxygen is used up

4.CO2 and heat is released

5.Temperature rises

1.Acetic acid is released

2.pH declines from 6.0 to 4.2

1.Lactic acid is released

2.Acetic acid declines

1.Lactic acid production continues(15-20 day)

2.Temperature declines

3.Bacterial activity stops at pH 4.0

Due to presence

of lactic acid,

further

degradation is

inhibited, as

fungal growths

are checked.

Lactic acid

fermentation

complete in 20

days.

Chemical Changes During Ensilage

• Sugars are fermented into volatile fatty acids (VFA) like lactic, acetic, propionic& butyric)acids by anaerobic microorganisms.

• The formation of the acids reduces the pH (target = 4)

• Protein is degraded into ammonia and NPN (target =<100g ammonia/kg totalNitrogen)

Factors required for good silage

• Airtight – to provide anaerobic conditions

• Moisture content in forage 60-65%

• Adequate soluble carbohydrates (>3%)

• Compaction of materials to exclude air

• Not contaminated with foreign matter e.g. soil

Characteristics of Good Silage• pH < 4.5

• Lactic acid 8 -12%, acetic acid 0.7-4%

• 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 material

SITE FOR CONSTRUCTION OF SILO

1. The place where we intended to construct silo should be elevated from other places.

2. The place must be free from water clogging.

3. Walls of silo pit must be leak proof.

4. It should at least six feet away from form animal shed.

SIZE OF A SILO

The silo size is determined by a herd size, the amount of daily feed, the number of feeding days and packed density of the raw materials

TYPES OF SILOS

• 2 Types

• Upright Or Tower Silo

• Horizontal silos- Pit

Trench

Stack

Bunker

TOWER SILO

• In this type storage

silos are cylindrical

structures, typically

8 to 10 m in diameter

and 15 m in height .

Tower silo

A BUNKER SILO is

generally built on the

ground

Side walls made of wood

and concrete are needed,

and

the interior is preferably

sealed by plastic sheets.

Proper pressure has to be

applied, and complete

sealing is required.

Bunker Silo

BUNKER SILO

Pit/Trench silo

• A TRENCH often dug into slope, sometimes lined with concrete, and used mostly in regions of low rainfall for making and storing silage.

Plastic bag silo

• In this type plastic bagswith thickness of 0.1 mmare taken and fill bagswith chopped rawmaterials, compressed asmuch as possible toremove the internal airand then sealedcompletely.

PLASTIC BAG SILO

KINDS OF SILAGE

SILAGE pH AMMONIA NITROGEN(%) BUTYRIC ACID

VERY GOOD 3.7-4.2 <10 NO

GOOD 4.2-4.5 10-15 LEAST AMOUNT

FAIR 4.5-4.8 15-20 LITTLE AMOUNT

BAD >4.8 >20 MORE

Judging the quality of silage

The quality of silage can be judged by its colour, smell, taste

and touch.Feeding of silage

2 - 3 Year Old Cattle. 11-13 Kg

3 - 8 Year Old Cattle 13-22 Kg

Sheep 1-1.5 Kg Per 45 Kg. Live Wt.

Goats 1-1.5 Kg Per 45 Kg. Live Wt.