Silage
Silage is usually made from grass crops including maize, sorghum or other cereals, using the entire green plant (not just the grain).
[2] Using the same technique as the process for making sauerkraut, green fodder was preserved for animals in parts of Germany since the start of the 19th century.
[4] The conditions of dairy farming in the United States suited the ensiling of green corn fodder, and was soon adopted by New England farmers.
[5] The favourable results obtained in the US led to the introduction of the system in the United Kingdom, where Thomas Kirby first introduced the process for British dairy herds.
[6] The modern silage preserved with acid and by preventing contact with air was invented by Finnish academic and professor of chemistry Artturi Ilmari Virtanen.
silos were made of stone or concrete either above or below ground, but it is recognized that air may be sufficiently excluded in a tightly pressed stack, though in this case a few inches of the fodder around the sides is generally useless owing to mildew.
[4] In the early days of mechanized agriculture (late 1800s), stalks were cut and collected manually using a knife and horsedrawn wagon, and fed into a stationary machine called a "silo filler" that chopped the stalks and blew them up a narrow tube to the top of a tower silo.
For pasture-type crops, the grass is mown and allowed to wilt for a day or so until the moisture content drops to a suitable level.
When the silo is filled or the stack built, a layer of straw or some other dry porous substance may be spread over the surface.
In New Zealand and Northern Europe, 'clamps' made of concrete or old wooden railway ties (sleepers) and built into the side of a bank are sometimes used.
[9] Silage undergoes anaerobic fermentation, which starts about 48 hours after the silo is filled, and converts sugars to acids.
How closely the fodder is packed determines the nature of the resulting silage by regulating the chemical reactions that occur in the stack.
[4] If the fermentation process is poorly managed, sour silage acquires an unpleasant odour due to excess production of ammonia or butyric acid (the latter is responsible for the smell of rancid butter).
[12] Plastic sheeting used for sealing pit or baled silage needs proper disposal, and some areas have recycling schemes for it.
Traditionally, farms have burned silage plastics; however odor and smoke concerns have led certain communities to restrict that practice.
When a silo is filled, fine dust particles in the air can become explosive because of their large aggregate surface area.
Silage gas contains nitric oxide (NO), which will react with oxygen (O2) in the air to form nitrogen dioxide (NO2), which is toxic.
Molds that grow when air reaches cured silage can cause organic dust toxic syndrome.
[18] Milk from cows fed with silage containing clostridial spores could represent a risk in hard cheese production.
