Chico State ag students research feeding brewery byproducts to cows
Chico State assistant professor Kasey DeAtley pulled a white pickup truck up toward a large pile of grain near a barn at the University Farm and motioned to it, as if to say, “Here it is.”
“It smells really great at this time,” she said as she leaned down and grabbed a handful. “It’s fresh.”
Typically, a pile of grain would be unimpressive, but this one was special. These particular oats had been used to produce beer. DeAtley, who teaches animal and range science in Chico State’s College of Agriculture, is working with her students to research the effects and cost efficiency of feeding the grain to dairy cows.
The university’s partnership with Sierra Nevada Brewing Co. started 17 years ago, DeAtley said, when the brewery decided to raise its own steers for beef to be served in its restaurant. Students at the University Farm raise, manage and process the Sierra Nevada cattle. They also conducted research on the effects of feeding them byproducts of the brewing process, including brewers’ grains—barley, etc.—stripped of their starches.
“Even when the brewers’ grain comes out of the brewery, it still has really great nutritional value to it,” DeAtley said. “The only stuff that comes out is the starch, which is used for the alcohol portion of the beer. So the grains are still very, very high in protein and high in energy, so it makes it a really good feed source for cattle.”
Researchers began studying the use of spent grain as a feed source in the 1960s, DeAtley said, though mostly with corn distillers. When she began teaching at the farm in 2009, California was in a literal drought and a figurative microbrewery monsoon. To that point, the farm fed brewers’ grain only to the steers, but reduced grazing land for milk cows and a surplus of brewers’ grain statewide led DeAtley and her students to wonder: Could we feed the grain to dairy cows, too?
“Feed prices were really, really high,” she said. “That, coupled with not having a lot of rangeland, made it difficult for producers. We kept getting the question: Is there any way we can feed the brewers’ grain to the cows? We couldn’t find anything in the literature. So we said, ‘Let’s do a study.’”
The study was organized with several goals in mind: To find out how long the grain would keep in storage, if it was healthy to feed spent grain to heifers, how microbes reacted to the grain in a cow’s stomach, and whether transporting the grain is economically feasible.
They’ve already answered some of their original questions. First, they determined that brewers’ grain will begin to dry out after five days in summer and fall heat; in colder months, the grain keeps for a few days longer. Then, in studying the heifers’ health effects of eating the grain, they found that they were identical to a control group fed regular feed. They created access ports in the cows’ first stomachs to best be able to study the digestion process (cattle have four stomachs).
Two years ago, Chico State partnered with the University of California’s Sierra Foothill Research Station to study the effects the grain has on dairy cows. To do this, cows at the research station were separated into two groups. One is fed brewers’ grain; the other a protein supplement. DeAtley expects this part of the study to take another year.
DeAtley said the partnership with the Sierra Foothill Research Station, which is 60 miles from Chico in Browns Valley, also offers an opportunity to research the economics of transporting brewers’ grain, which is 80 percent water, to areas farther away from a brewery. Previous research had indicated that 90 miles was the farthest one would want to ship the grain, to be cost-efficient.
“I don’t know if that’s still true today because our fuel prices have gone up so much. It may only be feasible within 40 miles of the brewery,” DeAtley hypothesized.
The explosion of microbrewing in California was an additional factor in the farm’s research, DeAtley said. According to the California Craft Brewers Association, a craft brewing advocacy group, the number of microbreweries in California grew from fewer than 70 in 1990 to more than 700 in 2016.
“We were just curious from a microbrewery standpoint, because we have all of these microbreweries all over the place and they are creating another feed source for producers that may be a little cheaper,” DeAtley said.
Scott Colby, communications manager at Sierra Nevada, said the brewery’s relationship with the University Farm is important on many levels. Studying the sustainability of grains will help more than just the local brewery, too. Spent grain “is of huge value for local farmers,” for both livestock and crops. DeAtley said the school’s farm alone receives 4 to 5 tons of brewers’ grain from Sierra Nevada every week.
“The really cool part about it is it completes that whole waste cycle,” DeAtley said. “We have grains going into the brewery, being processed for one thing, and coming out and not going to the landfill, but going back into the cattle and being utilized that way. It’s very cool.”
Ultimately, DeAtley, a Chico State alumna who herself studied in the farm science program, noted how the university’s partnership with Sierra Nevada and other organizations provides opportunities for hands-on teaching.
“The best part about it for me is that it creates research projects,” she said. “We get to create groups of cattle that have to be weighed. We have to take calculations and performance measures, which is phenomenal for the classroom. At the end of the day, if my students can’t be involved, then I don’t wanna do it.”