Can a single cell help solve major challenges in animal science?

This is where Yuan Yue, Assistant Professor at the Department of Animal and Veterinary Sciences at Aarhus University, believes cell models can make a difference.

At a recent seminar, she demonstrated how small clusters of cells grown in the laboratory can help answer major questions related to nutrition, animal welfare, disease prevention, and even climate-friendly livestock production.

"Many people think cell models are only useful for cell biologists," says Yue. "But they can be applied across many research fields. If you have a biological question, there is a good chance that cells can help provide the answer."

For Yue, the fascination lies in what happens around the cells. In the body, cells constantly receive signals from nutrients, hormones, microorganisms, and the surrounding tissue.

"A cell is never alone," she says. "Its environment influences what it does and how it responds."

By recreating parts of this environment in the laboratory, researchers can study the effects of individual factors one at a time. This can provide insights that would be difficult to obtain in living animals, where many biological processes occur simultaneously.

One example comes from nutrition research. Researchers may find that a specific nutrient improves milk production, but the mechanism behind the effect often remains unknown.

"We can investigate how these nutrients affect milk-producing cells directly," says Yue. "This allows us to understand what happens at the cellular level and why we see the effect in the animal."

The same principle applies to methane reduction research, a key focus area in animal science.

"There has been a great deal of attention on reducing methane emissions," says Yue. "But we should also understand how these interventions affect the animal and how the animal responds."

Cell models can help researchers investigate these questions by testing how cells react to compounds and metabolites produced as a result of methane-mitigation strategies.

Yue is equally enthusiastic about the use of cell models in infection research. Using advanced microscopy, researchers can observe how bacteria, parasites, and other disease-causing organisms interact with cells.

"Some pathogens actually enter the cells," she explains. "In cell models, we can follow this process and study how the infection develops over time."

These systems can help researchers evaluate vaccines, novel treatments, and feed additives designed to improve animal health before disease occurs.

Perhaps more surprisingly, cell models can also contribute to animal welfare research.

"When animals experience stress, they release signalling molecules that circulate throughout the body," says Yue. "We can study how these signals affect cells and tissues, giving us a better understanding of what stress means from a physiological perspective."

This can help connect behavioural observations with biological responses and provide a more complete picture of animal welfare.

However, Yue emphasizes that cell models are not intended to replace animal experiments.

"Animal studies will always remain important," she says. "But cell models allow us to test ideas, investigate mechanisms, and gain more value from the animal studies we conduct."