ANN 111: Principles of Animal Nutrition and Feed Technology (2+1)

PROCEDURE

• Strong high-density plastic bags with a capacity to hold 2 to 5 kg chopped green fodder and with no obvious holes in the seams are required. Glass desiccators or plastic containers of the same capacity may also be used.
• Fodder to be ensiled is harvested and brought to the chopping floor. The fodder is either hand chopped with a large knife against a wooden chopping block, or chopped through a chaff cutter with a rotating blade to a size of 1” length.
• Wilting of the fodder is carried out to reduce moisture percentage in order to reduce effluent loss. After wilting the forage should have a dry matter of 35 to 40 %.
• The chopped green fodder is carefully packed in the bag or desiccators. Carefully pack the material without making any damage to the bag or container.
• If necessary before packing additives can be added and mixed with the chopped green fodder. Example 1% molasses and 0.5 % salt can be added.
• After filling, the bag is gently but firmly squeezed by hand to expel air, and while compressed, the neck of the bag is to be twisted, turned over and tied with twine. In case of desiccators after filling to the brim, the contents are compressed and covered using a glass lid. Care is to be taken to prevent the formation of air pockets between the contents and the lid.
• The bag of silage is then inverted into a second empty bag, which is also closed and tied.
• The bag of silage is then inverted into a third empty bag and sealed. Each bag of silage is therefore triple wrapped, and seams that might be expected to leak air are doubly protected.
• For desiccators silage the gap between the lid and desiccator jar is sealed using molten wax.
• The bag or the desiccator is appropriately labelled giving details of fodder used, date of packing and due date for opening.
• The bags or desiccators are carefully stacked in a room protected against rats, mice and other pests.
• After a minimum period of one month the silo can be opened and silage subjected to analysis.

Characteristics of a good silage

• Very good silage
  • It is clean, the taste is acidic, and has no butyric acid, no moulds, no sliminess without proteolysis. The pH is between 3.5 and 4.2. The amount of ammoniacal nitrogen should be less than 10 per cent of the total nitrogen. Uniform in moisture and green or borwnish in colour. Taste is pleasing, not bitter or sharp.
• Good silage
  • The taste is acidic. There may be traces of butyric acid. The pH is between 4.2 and 4.5. The amount of ammoniacal nitrogen is 10-15 per cent of the total nitrogen. Other points same as of very good silage.
• Fair silage
  • The silage is mixed with a little amount of butyric acid. There may be slight proteolysis along with some mould. The pH is between 4.5 and 4.8. ammoniacal nitrogen is 15-20 per cent of the total nitrogen. Colour of silage varies between tobacco brown to dark brown.
• Poor silage
  • It has a bad smell due to high butyric acid and high proteolysis. The silage may be infested with moulds. Less acidity, pH is above 4.8. The amount of ammoniacal nitrogen is more than 20 per cent. Colour tends to be blackish and should not be fed.