Forage crops that are harvested for silage contain a natural (epiphytic) population of microorganisms. This will include both “good” microbes that will help to ensile the crop (e.g. lactic acid producing bacteria, LAB) and “bad” microbes, e.g. clostridia, enterobacteria, bacilli, yeasts and molds, which can cause poor fermentations, excessive dry matter, energy and nutrient losses, the development of off flavors/ aromas that reduce intakes and can even produce toxins that can compromise the health of your animals. Many of these “bad”, or spoilage, microbes require oxygen to grow, which is why it is important to use best management practices, e.g. packing the silage well and covering and sealing the silo, to ensure that the silage becomes anaerobic (oxygen-free) as soon as possible.
Using a proven, quality inoculant adds a large population of the good microbes to the ensiled crop, to dominate the ensiling process. Most of the microbes used in inoculants are LAB that are facultatively anaerobic. This means that they can grow both in the presence of oxygen and when all the oxygen is gone. By growing when oxygen is present the inoculant bacteria are also helping to speed up the process of making the material anaerobic. Once anaerobic conditions are achieved these same bacteria switch to fast, efficient production of acids, predominantly lactic acid but also some acetic acid, to reduce the pH and prevent the growth of spoilage microbes that are also able to grow in when there is no oxygen, e.g. clostridia, listeria.
The end result is better dry matter and nutrient retention and the production of better quality, more palatable silages that will give better production from your animal.