Production of high-quality silage involves winning a war fought on a microscopic level between “armies” of microbes that occur naturally. Forage inoculants help by reinforcing the beneficial bacteria in this fight. These products mostly contain lactic acid bacteria (LAB) that provide an efficient front-end fermentation to maintain feed quality and increase stability. There are many different LAB inoculants to choose from, and producers should select a research-proven product that will deal with challenges due to:
1. The crop being ensiled,
2. Local conditions,
3. Farm practices and
4. Silage history.
As a general rule of thumb, you can’t go wrong with an inoculant that drops the pH of the forage as quickly as possible, making a good fermentation better. A rapid pH drop will help maximize dry matter and nutrient retention and minimize the risk of spoilage. To achieve a rapid pH drop, look for homolactic LAB strains such as Pediococcus pentosaceus that are proven to convert sugars efficiently to lactic acid.
Next, it’s essential to ensure the LAB are not limited by their food supply. A good inoculant will contain enzymes to help feed bacteria. Also, using the right number of colony- forming units (CFU) per gram of forage will ensure sufficient amounts of “good” microbes to help producers win the fermentation battle. Look for an application rate of 100,000 CFU or greater for front-end fermentation inoculants. This is the effective level, as recognized by university researchers, and is based on using strains proven to dominate the fermentation.
Third, it’s important to consider the specific crop to be fermented and the harvest conditions. For example, ensiling wet hay crops can easily lead to the growth of clostridia and a butyric fermentation. Choose an inoculant proven to inhibit these undesirable fermentations, which can keep the resulting forage safe and clean to feed.
Utilize an inoculant proven to increase aerobic stability and prevent growth of spoilage yeasts — especially when inoculating high-moisture corn, silages only fed during the summer, silages that will be transported or moved, crops that have had excessive stress or insect damage, or crops that have slow feedout rates.
A forage inoculant is a small investment that can help save many tons of dry matter and help produce clean and high-quality silage. Especially when feed prices are high, animal productivity and farm profitability benefits by preserving high-quality forages.