What’s New in Inoculant: Bacillus pumilus

When it comes to improving forage quality, the inoculant market continues to evolve with new strains and formulations designed to maximize feed value and storage stability. One of the newest names gaining attention in the silage world is Bacillus pumilus. While lactic acid bacteria like Lactobacillus plantarum and Lactobacillus buchneri have been the backbone of inoculant programs for years, Bacillus pumilus is introducing some fresh possibilities.

What is Bacillus pumilus?

Bacillus pumilus is a naturally occurring, spore-forming bacterium. Unlike the lactic acid bacteria commonly used in silage inoculants, B. pumilus produces enzymes that can help break down tough plant fibers. This enzymatic activity can improve feed digestibility for livestock, potentially making more energy available from the same ton of forage.

Why is it being used in inoculants?

The main advantages of incorporating Bacillus pumilus into forage inoculants include:

• Fiber Breakdown: Its enzyme production, especially xylanases and cellulases, can reduce fiber fractions and improve forage digestibility.

• Resilience: As a spore-former, B. pumilus can survive challenging conditions, ensuring activity even in tough fermentation environments.

• Complementary Action: When used alongside lactic acid bacteria, B. pumilus supports both fiber breakdown and fermentation stability.

Potential Benefits in the Field

Farmers and nutritionists are watching closely to see how Bacillus pumilus performs across different forage types. Early research suggests:

• Increased neutral detergent fiber digestibility (NDFd)

• Better dry matter recovery from the bunker or silo

• Better control with bunk face heating

• More efficient utilization of high-fiber feeds like corn stalks, small grains, and alfalfa

In short, it’s not replacing the proven role of lactic acid bacteria in ensuring fast, stable fermentation—but it is adding another layer of value by enhancing forage digestibility.

What This Means for Your Operation

If your ration relies heavily on higher-fiber forages, an inoculant containing Bacillus pumilus could be a tool worth considering. Improved digestibility translates to more energy per pound of feed, potentially supporting higher milk production or weight gain without increasing feed costs.

From a safety aspect, controlling the heating on the face can greatly reduce steam and increase visibility, allowing the feed to be safely worked off.

As with any new technology, results may vary depending on forage type, harvest management, and overall ration design. Work with your nutritionist and agronomy team to evaluate whether B. pumilus could fit into your forage program.

✅ Bottom line: Bacillus pumilus represents the next step forward in forage inoculants—bringing enzymatic power to enhance digestibility, complementing the proven fermentation benefits of lactic acid bacteria.