Ensiling is an anaerobic process that helps preserve the nutritional value of the crop. It is a naturally occurring process that sounds simple, but it’s actually quite complex.
The two goals of silage production are:
- On the front end of the process, rapidly preserve forage for maximum recovery of nutrients and to minimize growth of spoilage microbes.
- On the back end, ensure silage has good feedout stability, with minimal heating and spoilage.
For producers counting on high quality silage, it pays to help this naturally occurring process along. A little assistance can result in consistent, high quality silage with minimal DM and nutrient loss or spoilage.
One of the most effective ways to help the fermentation process is through microbial forage inoculants. Microbial inoculants are often used to prevent clostridial fermentation (most commonly in wet alfalfa and grasses) and to improve aerobic stability, which is more of a concern in corn silage and high-moisture corn (HMC). High quality inoculants also help make a good fermentation even better by improving DM and nutrient recoveries.
The outcome of silage fermentation is determined by the dominant microbial species. Inoculants typically contain lactic acid bacteria, but different species and strains provide different results.
Inoculants containing homolactic acid bacteria generally help improve the rate of fermentation; they produce more lactic acid, reduce protein degradation and provide better energy and DM recovery.
However, lactic acid alone doesn’t have good antifungal properties. Therefore, we should consider different strains to help our second goal: good aerobic stability during storage and feedout. A specific strain, Lactobacillus buchneri 40788, has been uniquely reviewed by the FDA and allowed to claim improved aerobic stability in silage and HMC. It accomplishes this goal by producing acetic acid and 1,2-propanediol from lactic acid, during the storage phase.
Inoculants are not a substitute for good management practices. High quality silage can only be produced when silage inoculants are combined with a timely harvest and techniques to limit oxygen exposure. No matter what inoculant is chosen, it is important to pack efficiently and cover and seal bunkers or piles quickly and completely. During feedout, be sure to use good face management. Avoid removing silage too far ahead of feeding, don’t leave silage sitting in loose piles and feed out at a rate fast enough to avoid heating.
To download proceedings, or watch Dr. Schmidt’s full presentation at the 2016 Husker Corn Silage Conference, visit http://beef.unl.edu/silage-beef-cattle-conference. The conference was sponsored by Lallemand Animal Nutrition, the University of Nebraska Extension and the Iowa Beef Center.