Silage is the product resulting from natural fermentation of most plant material in the absence of air. Materials used for silage making are grass family i.e. maize, barley, Elephant (nappier) grass (penisetum puperum), sudan grass, Columbus grass, millet. Others are legumes such as Lucerne, vetch, cowpea, soya bean, clover and lupins. The brassica family such as kales and rape, root crops such as turnips, mangold and Swedes; and other plant material like sweet potatoes can be used as ensiling material.
Silage can be made from most cultivated crops but the quality of silage produced depends on the quality of forage material ensiled. Quality of material for ensiling is also dependent on
The stage of harvesting
The younger the plant the higher the protein content but the lower the carbohydrate content. Young plants with dry matter (DM) content less than 25% are difficult to ensile.
The kind of plant material
Grass family is rich in starch and sugar while legumes are rich in protein but poor in carbohydrates. Crop plants that have high protein levels are usually low in carbohydrate content and are difficult to ensile. In practice legumes are ensiled in a mixture with grasses.
Maize is the most popular and preferred material for ensiling. Maize should be harvested at dough stage, that is when the grains have just passed the milky stage. The DM content is high at this stage. For good fermentation the crop should be chopped finely. If large pieces are ensiled air pockets will lead to aerobic respiration and hence poor quality silage.