Ensiling

preserving feed in airtight spaces, the most common method of preparing succulent feeds. Ensiling has been practiced in Europe—in Sweden and the Baltic countries —since the 18th century. Beginning in the early 19th century the process was used in Germany to preserve sugar beet residue. In the second half of the century ensiling was adopted in France (in connection with raising fodder corn) and then in the United States, Great Britain, and Switzerland. The process was first used in Russia in the late 19th century, for the preservation of sugar beet tops and pulp residue and later for the preservation of clover, alfalfa, meadow grasses, corn, and feed root crops.

Ensiling involves the following operations: mowing the bulk greens or harvesting root crops or cucurbits; hauling, chopping, and loading the green crops into the silo; and compacting and covering the silage crop. Storage in an airtight structure prevents the development of aerobic bacteria and mold fungi. The lactic acid that forms as a result of the activity of lactic acid bacteria sours the feed (optimal pH is 4.2) and suppresses anaerobic decay and the development of butyric acid.

Sugar is the source of nutrition for lactic acid bacteria, and therefore the sugar content in feed determines its suitability for ensilage. Particularly suitable for ensilage are corn, sunflower seeds, annual and perennial cereal grasses, mixtures of cereals and leguminous herbs, feed cabbage, root crops and their tops, and cucurbits. Legumes and potato tops can be ensiled, but with difficulty. Nettles, the succulent tops of tomatoes, and gourds cannot be ensiled.

Ensiling is regulated by selecting raw material according to suitability as ensilage. Various chemical substances are added to difficult-to-ensile bulk material to prevent the development of undesirable microbiological processes. Surplus sugar in the silage crop is fermented by yeasts, and alcohol and carbon dioxide form. The moisture content of the raw material must not be greater than 75 percent, and temperatures should be 35°-37°C. Dry feed is added if the moisture content is above 75 percent. Overheating causes a decrease in nutritive value and the breakdown of vitamins. Chopping up the plant material causes the release of much cell sap; as a result, carbohydrates are used better by lactic acid bacteria, and lactic acid accumulates more rapidly. Chopped material is easier to mix with other feeds, to compact, to remove from storehouses, and to distribute to animals. Green plants are ensiled when their nutrient content is the greatest and before hardening.