a succulent feed preserved in an airtight container. Corn, potato, sunflower, vetch-and-oat, and other silages are distinguished. Silage is close in nutritive value to the green material that is ensiled. Carotene and vitamin C are preserved in silage, as are smaller quantities of water-soluble sugars. Organic acids are also present: lactic acid (up to 2 percent), acetic acid (up to 0.6 percent), and, in certain types of silage, propionic and valeric acids. When improper ensiling and storage procedures are employed, butyric acid may be present.
The feed value of silage depends on the ensiling method, on storage conditions, and on the type of plants used and their stage of development at harvesting. One hundred kg of sunflower silage contain approximately 16 feed units, 1.4 kg of digestible protein, 350 g of calcium, 160 g of phosphorus, and 1,500 mg of carotene. An equal amount of corn silage has approximately 20 feed units, 1.4 kg of digestible protein, 150 g of calcium, 50 g of phosphorus, and 1,500 mg of carotene. In 100 kg of alfalfa silage there are 18 feed units, 2.9 kg of digestible protein, 600 g of calcium, 60 g of phosphorus, and 2,500 mg of carotene.
Good silage is pale olive or yellowish in color; silage that has been exposed to a great deal of heat is dark brown. The odor of silage is reminiscent of sauerkraut or of soaked apples; it is sometimes fruity. When a great deal of warming has taken place, the odor resembles that of freshly baked bread or of honey. Spoiled silage smells like spoiled herring or manure. Silage must be crumbly in texture; an oily consistency indicates spoilage. With a moisture content of approximately 70 percent, the pH of good silage is 4.2. When the moisture content is 65 percent, the pH is somewhat higher.
The consumption of silage improves digestion and facilitates better utilization of other feeds, especially roughage. All farm animals are fed silage. Silage may constitute as much as 50 percent of the nutritive value in rations for dairy and beef cattle and as much as 20 percent in rations for swine. Special silage is prepared for calves, swine, and poultry. Silage for calves is prepared from legumes, soft cereals, and mixtures of legumes and cereals harvested during the early stages of development. For swine, combinations are used, consisting chiefly of sugar beets, carrots, potatoes, melons, and corn cobs. Silage for poultry consists of legumes, vitamin-rich gourds, carrots, beet tops, and sugar-beet roots. Silage is fed in the winter and, in arid regions, in the summer as well. In the USSR the total consumption of silage by cattle and poultry was 166.7 million tons in 1965 and 185.3 million tons in 1974.
S. IA. ZAFREN