Numerous inoculants exist in the marketplace today, each claiming to have various benefits. How do you know which type is right for your operation?

There are four main factors to consider when choosing an inoculant:

  • Do you need a fermentation aid, a spoilage inhibitor, or both?
  • Do you need enzymes?
  • Should you use water soluble or dry-applied?
  • Is it a quality product?

Fermentation Aids vs. Spoilage Inhibitors

The most common reason to use an inoculant is as a fermentation aid. These inoculants contain specific bacteria selected to promote a rapid fermentation and pH drop. Ensuring a rapid fermentation maximizes dry matter and nutrient retention. All forage crops can benefit from the use of a proven fermentation aid, especially with current feed costs and availability issues. A proper fermentation is of particular importance for crops that are typically more difficult to ensile, such as haylages.

For forage crops prone to spoilage after exposure to air, such as high moisture corn and higher dry matter corn silages, a proven spoilage inhibitor should be used. These inoculants inhibit the spoilage and heating that occurs after opening up the fermented silage for feed-out.

Some forages, such as drier haylages, exhibit both fermentation and spoilage challenges. In these cases, a combination inoculant, which includes both types of bacteria, will meet both of your needs.

Different types of forages are more prone to certain challenges than others. For more information on the differences between these types of inoculants and which is right for your specific operation, please visit Quality Remember to ask for data showing the efficacy of the product on the forage type you are producing.


Some inoculants contain enzymes, which provide a source of fermentable sugars, aiding the ensiling fermentation.  Enzymes are beneficial in all situations where available sugars may be limiting, e.g. haylages harvested in cloudy conditions, to ensure maximum dry matter recovery.  Some enzyme formulations have been shown to help improve digestibility: look for data to support any claims made.

Water Soluble vs. Dry-Applied

Water soluble inoculants are typically applied using specific applicators at the chopper. This achieves proper distribution across the entire forage crop. Rehydration with water means inoculant bacteria hit the crop live and ready to go, helping drive a faster fermentation. As always, good management is of key importance. Several important factors, including water quality and water temperature, need to be managed to ensure viability of the bacteria.

Dry-applied, or granular, inoculants are applied without the addition of water. Application is considered by some to be simpler; however the bacteria are not immediately effective due to a lag time needed to rehydrate them by pulling moisture out of the crop mass. This lag time slows the fermentation and can be an issue with crops that are harvested at a high dry matter (>50%)  While good quality dry applied inoculants can remain viable in the applicator hopper for 48 – 72 hours, after that viability will decline due to exposure to ambient humidity and temperature.


Once you have identified the type of inoculants that best fits your operation’s needs and challenges, it is important to keep quality in mind. Some of the factors that can help determine quality include:

  • Independent research to validate the specific product and strain
  • Independent research to validate the recommended application rate
  • Manufacturing according to strict controls and standards to ensure product viability
  • Proper, clear labelling detailing safe handling and proper use.

Ask the Silage Doctor at if you have questions about which inoculant is right for you.