Inoculant mythbusters: Clearing the smoke and mirrors

By Dr. Michelle Windle
Each year, inoculant companies and their representatives vie for your business.  Decisions should be made based on proven facts rather than marketing, smoke and mirrors.  Therefore, we’d like to share some myths we’ve heard as well as some scientific responses to help “clear the smoke.”

Myth:  All L. plantarum/L. buchneri are the same, so research from one strain applies to all.
Facts:  Not all bacteria with the same name behave the same.  For example, harmless strains of E. coli are in your mouth right now, however, if you consume the specific strain of E. coli O157:H7, you could die.  Likewise, not all L. plantarum or L. buchneri behave the same.  Look for the letters and numbers after the name, such as L. plantarum MTD/1.  Only research done on this specific strain can apply to this specific inoculant.

Myth:  Ensiling rained-on/wet haylage is fine, provided you inoculate.
Facts:  Inoculants are not a complete replacement for good management, but they do provide a buffer.  For example, while it may delay the process for a few days, no inoculant will prevent wet haylage from turning butyric.

Myth:  Inoculants are world travelers that can move throughout the silo.
Facts:  Distribution is key; inoculants only work where they are applied.  If applied unevenly, the silo typically has layers or spots of good and bad silage.

Myth:  Dosage doesn’t matter.  Applying less is fine and doubling the dose is twice as effective.
Facts:  During harvest, bacteria can multiply very quickly (sometimes doubling in minutes).  Thus, inoculation is a numbers game, and it’s crucial to start the “war” with a full “army” of good bacteria on your side.  However, a single dose is sufficient, regardless of the moisture content of the crop.  High-quality inoculants should contain aggressive bacteria that grow exponentially the second they hit the crop.  A double dose would have no effect except to double the price.

Myth:  You don’t need a mycotoxin binder because an inoculant will eliminate mycotoxins.
Facts:  Mycotoxins are predominately produced in the field.  It is absolutely impossible for any inoculant to detoxify mycotoxins in the silo.

Myth:  You can re-inoculate silage to prevent spoilage after it has been ensiled, if you are moving the silage from one structure to another.
Facts:  Typically, most sugars are consumed during the initial fermentation.  Inoculants need sugars to grow, so if an inoculant is reapplied to already-ensiled silage, it could not grow and would be a waste of money.  A better use of money would be to apply an acid, such as buffered propionic acid, which does not require a substrate to work.

Myth:  Granular is more effective than water-soluble inoculant.
Facts:  Dr. Limin Kung, Jr., one of the world’s leading inoculant researchers, compared the exact same bacteria in granular versus water-soluble inoculant form.  These findings indicated that, if a crop had sufficient moisture (about 35 percent dry matter (DM)), the inoculants both dropped pH similarly.  However, when the crop was drier (about 45 percent DM), the pH dropped slower and remained higher when granular inoculant was used.

Myth:  If you put granular inoculant into the applicator, you can let it sit in the applicator between cuttings.
Facts:  Good-quality granular inoculants typically come in heat-sealed, foil-lined bags to exclude ambient moisture.  However, once the bag is opened, the bacteria revive and begin to starve.  Thus, they need to be used within 48 hours, just as with a water-soluble inoculant.  This occurs regardless of the brand of inoculant.

Myth:  You need a different inoculant or application rate for different crops.
Facts:  Bacteria do not distinguish whether glucose from a corn plant is different from an alfalfa plant; it simply consumes the molecule.  Thus, a good-quality inoculant should be just as effective on different crops at the same rate.  The exception to this is high moisture corn.  High moisture corn requires a higher rate of application (typically one and a half times greater than the normal dose for L. buchneri) because the crop is so much more prone to spoilage and the DM is so different (typically less than half the moisture content).

At the end of the day, the best way to combat these myths are with facts.  We hope we’ve helped provide a “breath of fresh air” by providing research-proven, scientifically based answers.

This article was originally written for the January edition of Vita Plus Forage Foundations.  Click here for more forage management expertise.

About the author:  Dr. Michelle Windle is a Vita Plus forage products and dairy technical service specialist. Windle earned her bachelor’s and master’s degrees in animal science at the University of Delaware. She continued there to earn her Ph.D. in animal and food science, specializing in forage research with Dr. Limin Kung. Her thesis research centered on the use of a protease to improve starch digestibility earlier in the ensiling process. A New Jersey native, Windle gained much of her farm experience during her collegiate years, milking cows, working in a forage laboratory, and performing dairy research. Based in Madison, Wisconsin, Windle’s responsibilities at Vita Plus include forage product research and development, dairy research, and dairy technical services.