Get the most from your inoculant – Dr. Michelle Chang-Der Bedrosian and Nathan Hrnicek, Vita Plus

“You spend a lot of money focusing on yield and quality.  How do you retain as much of that as possible?”

Nathan Hrnicek, Vita Plus forage consultant, posed this question to attendees at the 2020 Vita Plus Custom Harvester Meeting.  During their breakout presentation, Hrnicek and Dr. Michelle Chang Der-Bedrosian, Vita Plus forage products and dairy technical service specialist, explained how inoculants can help preserve as much forage dry matter (DM) as possible.

Chang-Der Bedrosian described the four phases of silage:

1. Aerobic phase:  This phase begins when the crop is cut and continues until it is packed and sealed in the bunker or silo.  During this time, naturally occurring, aerobic bacteria (bacteria that grow and live when oxygen is present) consume forage DM as they grow and reproduce.  If you’ve ever let a wagon full of chopped forage sit overnight, you might notice it’s hot in the morning.  That’s because these bacteria produce heat during these processes.  Heat is lost energy that cows won’t be able to use to make milk.  Adequately packing the bunker or pile and sealing it with an oxygen-barrier plastic removes oxygen and moves the silage into the next phase.
2. Upfront fermentation:  Once oxygen is removed, anaerobic bacteria (bacteria that live and grow in the absence of oxygen) begin producing lactic acid, which lowers the pH of the silo and preserves it for storage.  This is one of the phases where inoculants can have an impact.  Upfront fermenters, such as Vita Plus Crop-N-Rich^® forage inoculant, speed up the fermentation process.  The faster the pH drops, the more DM is preserved.  Another benefit of a rapid pH drop is prevention of “bad” bacteria, such as Clostridia and enterobacteria, from growing.
3. Storage:  Silage “sits and chills” during this stage.
4. Feedout:  At feedout, oxygen is reintroduced to the silage “waking up” spoilage bacteria.  Yeast consume lactic acid, increasing the forage’s pH once again.  This is the second phase where an inoculant can help.  Lactobacillus buchneri 40788, found in Crop-N-Rich Buchneri and Crop-N-Rich Stage 2, produces acetic acid, which limits the growth of spoilage yeasts and molds.

With good management, Hrnicek said producers can expect 9% to 15% shrink on their forages.  That number can spike to as high as 40% with poor management (or poor luck).  Hrnicek and Chang Der-Bedrosian offered several tips to reduce shrink and retain as much high-quality forage as possible:

• Start with good-quality forages harvested at the right maturity and moisture.  The ideal moisture content for corn silage is 65% to 68% (23% to 35% DM).  Ideal moisture for haylage is 55% to 60% (40% to 45% DM).
• Use the right solution for the problem.  An upfront fermentation inoculant is usually a good choice to recover as much DM as possible.  If spoilage at feedout is an issue – for example, if you notice forages heating at the feedbunk – consider using an inoculant that contains L. buchneri 40788.  Propionic acid may also be used to reduce spoilage.  However, Chang-Der Bedrosian said the acetic acid produced by L. buchneri 40788 is more efficient at killing spoilage bacteria, and purchasing this inoculant is often cheaper than propionic acid.
• Choose an outstanding inoculant.  Carefully evaluate the label of your inoculant and make sure it contains adequate amounts of effective bacteria to get the job done.  Your supplier should be able to provide you with proof of efficacy.  If it isn’t backed by sound research, don’t use it.
• Treat it well.  Follow the directions for storing, handling and applying your inoculant.  Note that bacteria can start dying at 80 degrees F; adding frozen water bottles to your inoculant tank can help reduce the temperature.  Do not let reconstituted inoculant solution freeze as this could also kill the bacteria.  If you’re harvesting during freezing conditions, add a small amount of propylene glycol to the tank to keep it from freezing.  For bunkers, piles and baleage, applying the inoculant at the chopper is preferred.  With bags and upright silos, applying inoculant at the blower is fine.