Fermented Forage - Guidelines and How-To

Fermenting forages is a great way to increase nutrition for your livestock. Bio Minerals Technologies has a Probiotic Fermentation Culture that creates exceptional forage in many forms. We specialize in fermenting high-moisture forages for maximum animal nutrition. We have many farmers who use our products and methods to successfully ferment high-moisture, baled alfalfa and other forage without excessive heating. The cattle love the fermented forages and they will eat fermented before they eat anything else.

General Guidelines

There are some critical details you should adhere to when baling high-moisture forages. You can ferment alfalfa, grass, barley, oats, or wheat straw, even corn stalks. You can ferment them in round or square bales as well as in pits or bags. General Fermentation Culture application rates are shown in the table below. Specific fermentation process details are given in the sections following the table.

Fermentation Culture Application Rates

  Moisture Range Purpose Minimum Maximum
Clean, low-moisture forage (traditional) 12-18% Inoculation 1/2 gallon/ton 1 gallon/ton
Clean, high-moisture forage 25-65% Fermentation 1/2 gallon/ton 1 gallon/ton
Extremely high-moisture forage 65-85% Fermentation/
1 gallon/ton 1.5 gallon/ton
Moldy or spoiled high-moisture forage 45-85% Fermentation/
1 gallon/ton 2 gallon/ton
Wheat (grain) straw - wet

25-65% Fermentation 1 gallon/ton
+ 8 oz molasses
1.5 gallon/ton
+ 12 oz molasses

Note: Fermenting bales and forages will initially heat up as high as 170 degrees. Square bales are more likely to reach higher internal temperatures than round bales because they are more tightly compacted and have a larger anaerobic zone where the microbes are most active. After baling and before stacking in full stacks, monitor bale temperatures carefully. Once the internal temperatures have peaked and dropped down to the long-term 80-105 degree fermentation range, the bales can be stacked and covered in their final destination.

For a specific example, read about a high-moisture salvage fermentation we did in Idaho a few years ago.

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Low Moisture Forages

Low-moisture forages between 12-18% are the standard for most forage operations. Apply the fermentation/probiotic culture as an innoculant at baling to protect against mold and other pathogens. Bale your forage at 18% in order to retain more leaves and plant nutrition (alfalfa will keep up to 25% more leaves at 18% instead of 12%). Retaining the leaves will improve the nutritional value of the forage (greater Relative Feed Value or RFV).

At these low moisture levels, the bales will not ferment, but the application of our fermentation / probiotic anaerobic microorganisms will help prevent the growth of mold producing pathogens. The bales will experience very little heating (due to the presence of the beneficial microbes). Within a few weeks, the moisture levels will drop naturally. Even though the bales are not fermented, cattle and livestock can detect the presence of the probiotic microorganisms and they will select this above other non-treated forage. The probiotic microbes create a significant benefit to the cattle who consume the forage, improving their digestion and feed conversion and strengthening their immune system.

High Moisture Forages

A moisture range between 25% to 65% is where you’ll see the best fermentaion; less at 25% and much more at 65%. The microbes will work much better with the higher moisture content. The ideal moisture range for square bales seems closer to 35% to maintain good bale structure through the fermentation process. Bales at higher moisture levels, 45 to 65%, get soft and do not stack as well.

In these fermented bales you will see:

  • Initial temperatures up to 170 degrees as the beneficial microbes gain control of the environment and multiply and start breaking down the forage
  • Caramelizing and darkening of the intererior forage
  • In round bales, you may see beneficial yeasts growing on the outer edge of the caramelized layer. This is Not mold.

Fermenting bales show two types of fermentation zones. Tthe center core where there is no oxygen will caramelize and break down. The outer layer will show whitish and grayish yeast accumulations. This is Not mold. The beneficial yeasts grow at the transition boundary where the anaerobic zone becomes aerobic. About one half of our fermentation microbes are facultative, meaning they can function in both anaerobic and aerobic environments. As these microbes continue to break down the forage in the aerobic environment, the result is the generation of the beneficial yeasts. Livestock will readily eat this outer part of the bale as aggressively as the inner part of the caramelized bale. Cattle will not eat moldy hay, they can tell the difference.

Due to their looser structure, the best way to ferment round bales is to wrap them. This will retain the moisture and maintain a better fermentation environment for the microbes. Round bales generally do not heat up as much as square bales, again, due to the looser structure. Fermentation will still occur (especially if they are wrapped securely).

Note: Late fall forages that will not have adequate drying time can be cut, baled at higher moisture levels and fermented and preserved as a superior forage.

Extremely High Moisture Forages

This would be forages from 65% to 85% moisture range. Our experience is we can bale this material up and save it from spoilage but it doesn’t make the best fermented forages. In the past these have been more ‘salvage’ type operations to save the forage from molding and spoiling to a point it is unusable.

The best rate for these conditions would be at least 1 gallon of fermentation culture per ton of forage. Square bales and round bales will be more difficult to handle and stack due to their increased water weight. In most cases we have been able to save the forage.

Spoiled/Moldy High Moisture Forages

Often forages will get rained on, sometimes multiple times, turned and turned again, and become difficult to dry out and eventually become moldy. Using a MINIMUM of 1 gallon to 1.5 gallons (one and a half gallons) even as high as 2 gallons the forage can be saved. The blend of biology in the fermentation culture will kill the pathogenic microbes and digest and eliminate their toxic metabolites of Zearalenone, Aflotoxins B1, B2, G1, G2. You can read about an example in this article.

Heat Ranges of Forages

Bales can heat up during fermentation depending on the type of forage and level of moisture in the forages. The more moisture you can retain in the baled forage, the longer and better fermentation results you will get. This is why wrapping and tarping the fermenting forage is essential.

Grass forages tend to lose moisture quickly after cutting and the bales tend to retain less moisture after baling. These forages tend to ferment less after baling. Optimally you want to wrap these grass forages to prevent moisture loss and extend fermentation and pre-digestion.

Alfalfa holds stem and leaf moisture well. It’s an ideal forage for fermenting, best wrapped, covered or tarped.

When bales/forages heat up during the fermentation process, this is from the reproduction of the microorganisms inside the bale from both beneficial microbes we apply and naturally occurring microbes from the environment that were on the forage when it was cut. All these types and groups of microbes are going to reproduce and grow, thus we get elevated temperatures. Temperatures can reach as high as 170 degrees within several days after baling. What is occurring is biological warfare inside the bale. Each type of biology (good or bad) is trying to reproduce and take over and control the environment inside the bale. The fermentation culture is designed to kill off the pathogenic populations of biology inside the bale and thus control the heat, fermentation and extended breakdown and pre-digestion of the bale’s inner forages. Once the other biology groups are eliminated the bale temperatures will begin to drop back into normal fermentation ranges of 80 to 110 degrees (depending on forage type) for an extended period of time. Once the temperatures drop, move the bales into a stack, hay barn or covered area. DO NOT stack high heating bales, let the temperatures drop before storing them in a more permanent location.

This is why it is very important to use ENOUGH fermentation culture so you get enough beneficial microbes on the forage materials to take over and remove those other non-fermenting, pathogenic and toxic/flammable gas producing microbes from the forage materials. Microbes that produce methane are everywhere, including inside wet forages; eliminating them will prevent fires. THERE ARE NO FLAMABLE GAS PRODUCING MICROBES IN THE FERMENTATION CULTURE.

IMPORTANT: If you miss forage or do not get enough fermentation culture on the forage then you might not be able to overtake / control the other populations of microbes that can be on the forage. This could result in molding, overheating and even fires.

Wheat Straw Fermentation

Wheat straw fibers, which are made up of hemi-cellulose, cellulose and lignin, are generally used as bedding and or ‘fillers’ in livestock rations. The carbon chains of the straw fibers are very long chains and non-digestible. Yet these long carbon chains hold incredible amounts of glucose (a short chain sugar) that the animal uses to create energy. Fermenting up wet wheat straw and wrapping the bales or covering them in stacks with tarps will allow the fermentation and pre-digestion required to convert these long chain polysaccharides into more absorbable short carbon chain sugars, so the livestock can utilize the glucose as energy instead of passing it through undigested. Most livestock will eat fermented straw at nearly equal rates to hay or alfalfa. Animals prefer fermented forages to all other forages.

Saving Winter Calves

Fermented forages will save a lot of winter-born calves from dying. These beneficial microbes during fermentation produce a wide range of probiotic substances and as baby calves begin to nibble on the fermented forages, these beneficial microbes inoculate the rumen and prevent other environmental pathogens such as E Coil, Salmonella, Clostridium Botulinum and others to get established in the calves rumen and make them sick. The probiotics substances boost the immune system to further prevent disease and increase health and growth.

Protecting Fermented Forages

Fermented forages are a very valuable resource. When you go to the extra work of preserving and fermenting your forages be sure to take proper care of it. Shelter, cover or wrapping the bales will keep fall rains and winter snow off the bales and prevent the cold and water-logged conditions that can allow forage materials to spoil. Protecting your forages from the elements will give you the best results.

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