Rebecca Smith Advances Sorghum Research for Dairy Feed

By Blake Jackson

Inside the King Hall greenhouse at University of Wisconsin-Madison, researcher Rebecca Smith carefully studies rows of sorghum plants engineered to make their cell walls easier to break down. Working with samples of stalks, seeds, and frozen plant tissue, Smith is investigating how modified crops could improve renewable fuel production and livestock nutrition.

Smith, an assistant professor in the Department of Plant and Agroecosystem Sciences at CALS, focuses on how forage and bioenergy crops develop at the cellular level.

The sorghum plants contain added DNA that increases chemicals capable of weakening cell wall bonds, making stored carbohydrates easier to access and convert into energy.

Researchers are testing which plants maintain strong growth while also becoming easier to process after harvest.

As part of her work with the Great Lakes Bioenergy Research Center and the Dairy Innovation Hub, Smith aims to develop crops that support sustainable agriculture, lower greenhouse gas emissions, and improve feed efficiency for cattle.

“The goal is to improve digestibility,” Smith says. “There are synergies in what makes a good plant for biofuel and for feed.”

A major focus of her research is lignin, a structural compound that helps plants survive environmental stress but also limits access to energy stored in plant fibers.

In biofuel production, lignin makes refining more difficult and expensive. In cattle feed, it slows digestion and contributes to methane emissions.

“We have to use what we know about cell biology so that we can manipulate lignin in specific cell types rather than in the entire plant,” Smith says. “No farmer wants to grow a plant that is going to fall over or is going to be ridiculously short.”

Originally from Winnipeg, Manitoba, Smith became fascinated with plant science while studying biology in high school. “Things just started clicking in my brain,” Smith says.

“It was just that concept of plants taking in carbon dioxide and turning that into energy, and then they’re releasing oxygen, and they’re supporting our life on Earth.”

Using tools such as CRISPR gene editing, Smith is now working to reduce the cost of biofuel production while helping dairy producers improve cattle digestion and sustainability.

Photo Credit: chelsea-mamott