Welcome to the MedLibrary.org Wikipedia Supplement on Silage -- Please Click to Return to Front Page

For the Christian Alternative band, please see Silage (band)

This article or section relies largely or entirely upon a single source. Please help improve this article by introducing appropriate citations of additional sources. (October 2007)

Silage is fermented, high-moisture fodder that can be fed to ruminants (cud-chewing animals like cattle and sheep)¹ or used as a biofuel feedstock for anaerobic digesters. It is fermented and stored in a process called ensilage or silaging, and usually made from grass crops, including maize or sorghum, using the entire plant, not just the grain. Silage can be made from many other field crops, and other terms (oatlage for oats, haylage for alfalfa) can be used.

It is sometimes a mix of two crops, such as oats and peas. Haylage means ensiled forages, made up of grass, alfalfa and alfalfa/grass mixes. This is used extensively in the Midwest and Northeastern areas of the United States. It is also used widely in Europe for dairy cattle diets.

Balage is another form of stored forage. In this case hay, alfalfa or grass is cut and baled while still fairly wet. That is, it is too wet to be baled and stored as hay. In this case the dry matter is around 60 to 70%. The bales are wrapped tightly in plastic wrappers. The material then goes through a limited fermentation in which short chain fatty acids are produced which protect and preserve the forage. This method has become popular on smaller farms.

Contents 1 Making silage 2 Fermentation 3 Silo effluent 4 Storing silage 5 Anaerobic digestion 6 Safety 7 Nutrition 8 See also 9 References

Making silage

This section does not cite any references or sources. Please help improve this section by adding citations to reliable sources. Unverifiable material may be challenged and removed. (June 2008)

Silage must be made from plant material with a suitable moisture content, about 50% to 60%, depending on the means of storage the degree of compression and the amount of water that will be lost in storage. For corn, harvest begins when the whole-plant moisture is at a suitable level. For pasture-type crops the grass is mowed and allowed to wilt for a day or so until the moisture content drops to a suitable level.

The plant material is collected, chopped into pieces about 1/2" (14 mm) long and packed. In the early days of mechanized agriculture, stalks were cut and collected manually using a knife and horsedrawn wagon, and fed into a stationary machine called a "silo filler" that would chop the stalks and blow them up a narrow tube to the top of a tower silo. Current technology uses mechanical forage harvesters that collect and chop the plant material, and deposit it in trucks or wagons. These forage harvesters can either be tractor-drawn or self-propelled. Harvesters blow the silage into the wagon via a chute at the rear or side of the machine. Silage may also be emptied into a bagger, which puts the silage into a large plastic bag that is laid out on the ground.

In California, Australia, and frequently in New Zealand, silage is placed in large heaps on the ground and rolled by tractor to push out all the air, then wrapped in plastic covers held tight by recycled tires.

In New Zealand and Northern Europe the silo or "pit" is often a concrete bunker built on the side of a bank so that chopped grass can be dumped in at the top and drawn from the bottom in winter. This requires considerable effort to compress the stack in the silo to cure properly.

Fermentation

Silage undergoes anaerobic fermentation, which starts about 48 hours after the silo is filled. Traditionally, the fermentation is caused by indigenous microorganisms, but today, some silage is inoculated with specific microorganisms to speed fermentation or improve the resulting silage. The process converts sugars to acids and exhausts any oxygen present in the crop material. The fermentation is essentially complete after about two weeks. Silage inoculants contain one or more strains of lactic acid bacteria, and the most common is Lactobacillus plantarum. Other bacteria used in inoculants include Lactobacillus buchneri, Enterococcus faecium and Pediococcus species.

Silo effluent

The fermentation process releases liquid. Silo effluent contains nitric acid (HNO₃), which is corrosive. It can also contaminate water courses unless precautions are taken. The high nutrient content can lead to eutrophication (growth of algae blooms).

Storing silage

Silage must be firmly packed to minimize the oxygen content, or it will spoil.

Anaerobic digestion

Silage is a useful feedstock for anaerobic digestion. Here silage can be fed into anaerobic digesters to produce biogas that in turn can be used to generate electricity and heat.

Safety

Silos are hazardous, and people die every year in the process of filling and maintaining them. There is a risk of injury by machinery or from falls. When a silo is filled, fine dust particles in the air can become explosive because of their large aggregate surface area. Also, fermentation presents respiratory hazards. "Silo gas", consisting primarily of nitrogen dioxide, is released in the early stages of fermentation, and can kill. Lack of oxygen inside the silo can cause asphyxiation. Molds that grow when air is allowed to reach cured silage can cause toxic organic dust syndrome. The silage itself poses no special danger.

Nutrition

This section does not cite any references or sources. Please help improve this section by adding citations to reliable sources. Unverifiable material may be challenged and removed. (June 2008)

The ensiled product retains a much larger proportion of its nutrients than if the crop had been dried and stored as hay or stover. Silage is most often fed to dairy cattle, because they respond well to highly nutritious diets.

Since silage goes through a fermentation process, energy is used by fermentative bacteria to produce volatile fatty acids (VFA), such as acetate, propionate, lactate, and butyrate, which preserve the forage. The result is that the silage is lower in energy than the original forage, since the fermentative bacteria use some of the carbohydrates to produce VFA. Thus, the ensiling process preserves forages, but does not improve the quality or the nutrient value.^{citation needed}

See also

• Grain crimping

References

Feeding baleage to horses - the ultimate guide - Horsetalk.co.nz

• Making and Feeding Silage, John Murdoch, B.Sc, Ph.D. Published by Dairy Farmer (Books) Limited, Lloyd's Chambers, Ipswich, U.K. (regret no date, probably 1960's)

Wikipedia content modification information:

• This page was last modified on 16 October 2008, at 00:35.

Wikipedia Authorship and Review

Wikipedia content provided here is not reviewed directly by MedLibrary.org. Wikipedia content is authored by an open community of volunteers and is not produced by or in any way affiliated with MedLibrary.org.

Wikipedia Usage Guidelines

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article on "Silage".

The URL for this specific entry is:

• http://medlibrary.org/medwiki/Silage

All Wikipedia text is available under the terms of the GNU Free Documentation License. (See Copyrights for details). Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc.