In May, Hill's Pet Nutrition earned a key clearance from the U.S. Food and Drug Administration for a lamb protein yeast ingredient made through precision fermentation, a first for the pet food industry. Alongside Bond Pet Foods, Hill's has spent more than five years applying precision fermentation—a proven technology long used to produce human food ingredients for cheesemaking, as well as enzymes and vitamins—to craft a lamb protein yeast, which delivers the same amino acids as traditional meat protein.

The result provides a new option for ingredient sourcing, which supports the overall goal of diversifying the supply chain.

Key takeaways

• In May 2026, Hill's Pet Nutrition received a no objection letter from the U.S. Food and Drug Administration (FDA) for a lamb protein yeast ingredient made through precision fermentation, a first for the pet food industry.

• The high-quality protein is crafted through precision fermentation, a proven technology long used to produce human food ingredients for cheesemaking, as well as enzymes and vitamins, which produces a high-quality protein without harming animals.

• It delivers a complete amino acid profile, similar to conventional animal protein — only the way it's made is different.

• Hill's chose lamb first because it can be difficult to source, and because pets find it especially palatable.

Why is Hill's Pet Nutrition making high-quality protein without animals?

Hill's Pet Nutrition is developing a high-quality protein without the animal to safeguard the future of pet nutrition.

With a changing climate, new pressures on the global food supply, and a world where pets and people increasingly draw from the same protein sources, Hill's Pet Nutrition understands that producing enough high-quality protein will only get harder.

Precision fermentation is a way to future-proof our protein supply by securing high-quality protein for pets without drawing from the same sources people depend on.

No one had brought this kind of high-quality protein to pet food. The team wasn't looking for an off-the-shelf ingredient but one specified to Hill's exact nutrient standards, made through a process no one had used in this way before.

Finding it started with an innovation brief to Plug and Play Animal Health, a world-class agricultural tech and animal health innovation hub Hill's helped found in Topeka, Kansas. That search surfaced Bond Pet Foods, a startup creating high-quality protein in a way the industry hadn't seen.

From there, it took years of careful work: scaling delicate lab science into real production, then proving the protein's safety and quality through a rigorous FDA review. 

How is lamb protein yeast made?

Bond Pet Foods' precision fermentation platform uses optimized yeast cultures to produce a high-quality protein ingredient that is nutritionally comparable to those derived from conventional animal sources, providing a consistent, scalable and environmentally responsible protein source for pet food manufacturers.

For Hill's, the appeal started with how the protein could be built. "We're a nutrient company first," says Jennifer Mitchell, Innovation Director, Marketing, at Hill's. Rather than reshape a recipe around whatever ingredient is available, the team could help shape a high-quality protein to help meet pets' exact nutrient needs from the start.

Turning that idea into reality took years of shared work. Bond scaled its science into large batches, and at Hill's Global Pet Nutrition Center in Topeka, our scientists put the new protein to the test. The protein ingredient then went through a six-month feeding study in healthy dogs, measuring taste, digestibility and safety, resulting in pivotal evidence that was key to the successful FDA review. 

Hill's chose Bond for a reason. "Their level of scientific rigor matches our own," says Jennifer Radosevich, Senior Vice President of Product Development, R&D, at Hill's. For Bond, the scale-up marked real progress, too: "Producing tons of product at scale is a major milestone in the collaboration," says Rich Kelleman, CEO of Bond Pet Foods.

Is precision fermented protein comparable to traditional animal protein — and is it safe for pets?

Yes on both counts. Lamb protein yeast provides a complete amino acid profile —the same kind of nutrients pets get from conventional animal protein, produced in a different way. It isn't a plant-based substitute or a lab-grown, cultured meat. Precision fermentation uses optimized yeast cultures to produce a protein ingredient that is nutritionally comparable to one derived from conventional animal sources. 

Hill’s rigorous safety testing paved the way for a "no objection" letter from the FDA, which clears the protein for use in dog food at up to 15% inclusion, in every U.S. state. It confirms the agency has no concerns with the ingredient's safety, the final step before it can be used in food sold to pet parents.

What's next?

Hill's and Bond are already developing a second protein, and the goal reaches beyond any single ingredient: to help the whole industry move toward more diverse protein options.

Breakthroughs like this don't happen alone. By reimagining how protein is made, we're working toward a healthier future for pets, the people who love them and the planet we share.

Foods made with the new precision fermented proteins are still in development.