Right now, it is the time when corn stalks, peanut pods, pastures, etc. are harvested for silage for livestock and poultry feed. Silage is a kind of succulent feed that is filled with fresh green fodder in a closed silo, fermented by microorganisms, and made of soft, juicy, fragrant, nutritious, easy-to-store, livestock-like food. However, farmers need to be reminded to prevent secondary fermentation of silaged silage when feeding. Secondary fermentation refers to the silage produced in the ventilated section due to the increase in the temperature in the pit when the silage is fed in the open cellar. The reason why the secondary fermentation of silage occurs is that silage under the condition of oxygen in the closed state is exposed to air, and the aerobic bacteria are mobilized. In particular, when the temperature is high, silage with better quality is susceptible to secondary fermentation. After secondary fermentation, the sugar content of silage can be lost by 10% to 24%. If there is a large amount of mold activity and mildew or nitrite is produced, after feeding the cow, there will be a certain degree of harm to the cow or adverse consequences. The methods for preventing the secondary fermentation of silage mainly include the following: When the silage is chopped, it should not be too long, suitable for 1cm-2.5cm; the moisture content should be 60%-75%; the density should be high; the weight per cubic meter should be high. Must not be less than 700kg; raw materials should be timely harvested, in particular should prevent corn stover frostbite. After each silage is taken out, the surface is covered with a plastic sheet so that it is not ventilated. If the seal is not strict, appropriate amounts of chemical agents such as propionic acid, urea and ammonia can be added to prevent mildew.