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Eaten and enjoyed for centuries
Our fungus is traditionally used to make oncom, an Asian fermented food similar to tempeh, and makes absolutely zero mycotoxins — one of the cleanest safety profiles of any fermented product.
Improving fiber digestion in cattle
Unlock energy in forage.
Gilly makes a prebiotic feed additive that helps cattle digest more fiber — turning ordinary forage and low-cost byproducts into more milk and meat, while improving feed efficiency and lowering cost for producers.
Partner farm
California's Central Valley
Backed by
How it works
A boost for the rumen's own fiber-digesters.
A cow's rumen depends on a small, outsized group of microbes: anaerobic gut fungi make up only about 8% of the rumen microbiome, yet drive up to 50% of plant biomass breakdown. Gilly's additive supports these fungi by favoring strict anaerobes and stimulating greater fiber colonization and enzyme output.
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Fed as a prebiotic
A small amount — under 0.5% DMI — folds into existing feed through the channels producers already use.
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More from every bite
The cow draws more energy from the same feed — and from cheaper byproducts most rations can't fully use — so output holds up while feed cost comes down.
Why Gilly
Feed is the biggest cost on the farm. We make it go further.
At roughly 5–15¢ per cow per day, Gilly typically returns 20–70¢ in added milk and meat value — a two-to-fivefold return that earns its place in the ration on economics alone, not subsidies or sustainability premiums.
5–15¢
Gilly feed cost
20–70¢
Added value
More from the same feed
Feed efficiency improves by up to 3–5% — more milk and meat without changing the ration.
Lower feed cost
A few cents per head per day that returns several times its cost.
Use cheaper byproducts
Unlock byproduct feeds like almond hulls and grape pomace in place of expensive forage.
Lighter footprint
Less land, water, and methane per gallon of milk and pound of beef.
Proof
Lab-tested.
Farm-bound.
Progressing from third-party rumen testing to commercial feeding and university study.
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Strong in vitro rumen results
Our additive improved fiber digestibility (48-hour IVNDFD) by up to 16 points.
DMI
Sustained intake
Palatability established in commercial heifer feeding trials at Trinkler Dairy in Ceres, California.
In vivo trial underway
A milk production feed trial is underway with Pennsylvania State University Dairy Sciences, concluding Spring 2027.
Team
Fungal technology meets deep dairy expertise.
Bo Xu
Founder & CEOPhD at UC Berkeley Plant and Microbial Biology, and founder of Ashby Fungi, a commercial mushroom farm in Berkeley. Leads Gilly's fungal strain development and production process.
Conor McCabe
Ruminant ScientistPhD in Animal Biology (UC Davis, Mitloehner lab) and a Cornell Dairy Fellows alumnus. Leads animal science, trials, and dairy-industry relationships.