As farms look for ways to bring more homegrown feed into the ration, high-oleic soybeans are starting to show up on the radar. They offer a combination of protein and energy, and recent research suggests they may also help support milk fat production while easing some of the milk fat depression risk often associated with conventional soybeans.
“High-oleic soybeans give producers another way to bring homegrown fat and protein into the ration while lowering some of the milk fat depression risk we typically associate with full-fat soybeans,” says Katelyn Goldsmith, dairy outreach specialist for the University of Wisconsin–Madison.
The difference starts with the fat inside the bean. Conventional soybeans carry more linoleic acid, a fatty acid often linked with milk fat depression when levels climb in the ration. High-oleic soybeans are built differently, with a higher share of oleic acid and a much smaller amount of linoleic acid.
Goldsmith points out conventional soybeans are made up of about 54% linoleic acid and 23% oleic acid. High-oleic soybeans flip that relationship, with about 75% oleic acid and roughly 10% linoleic acid.
“It’s important to remember these are still fundamentally a protein source,” Goldsmith says. “But the fatty acid profile gives them some added flexibility compared to conventional soybeans.”
Both soybean types deliver similar nutrient levels overall, with crude fat typically around 20% to 22% and crude protein near 40%. The difference, researchers say, comes in how that fat behaves in the rumen and how it may influence milk components.
Feeding Trail Results
Most feeding studies with high-oleic soybeans have focused on milk production, milk components, and dry matter intake. Results haven’t always moved in the same direction, largely depending on diet makeup, processing, and what the soybeans replaced in the ration.
Milk yield changes have generally been modest, with some studies showing small gains and others showing little to no response. Researchers point out that energy balance and ration structure often explain much of that variation.
Milk fat, however, has been the most consistent response. Several studies have shown increases in both milk fat percentage and total milk fat yield when high-oleic soybeans replaced conventional soybeans in the ration.
Milk protein and dry matter intake shifts have been smaller and less consistent, and many of those differences have not been statistically significant.
“Cow responses can vary depending on the overall ration and feeding strategy,” Goldsmith says. “It’s important to evaluate how these soybeans fit within the entire diet rather than focusing on one ingredient alone.”
Processing Still Plays a Part
Like conventional soybeans, high-oleic soybeans are typically roasted before feeding. Roasting improves protein digestibility, increases rumen undegradable protein, and reduces anti-nutritional factors.
Commercial access to roasted high-oleic soybeans remains somewhat limited, so many farms are roasting on-farm or using mobile roasting services.
Particle size also matters. Feeding processed soybeans tends to produce more consistent results than feeding whole beans. Research has used grind sizes similar to soybean meal, around 700 to 800 microns, with success.
“Finding the right balance is important,” Goldsmith says. “If soybeans are ground too finely, you can lose some of the rumen bypass protein benefits and potentially create challenges with fiber digestion or milk fat.”
At the same time, under-processing can reduce digestibility and limit the value of the bean.
Feeding Rates and Economics
Research has looked at inclusion levels anywhere from 5% up to 24% of dietary dry matter, but those higher rates are not necessarily practical for every herd.
Goldsmith suggests starting conservatively and building from there with a nutritionist.
“For many farms, somewhere around 8% to 12% of dietary dry matter can be a practical starting point,” she says. “From there, monitor body condition, production and component response to see how cows are performing.”
Some herds may see the most value in high-producing groups, where oleic-rich fat sources tend to show the strongest response.
Economics will ultimately decide how widely high-oleic soybeans are used. They often carry a premium over conventional soybeans, and farms also need to account for roasting, storage, labor and equipment.
Still, gains in milk fat production and the ability to replace purchased fat or protein sources can help offset some of those costs.
“Every farm’s economics are going to look different,” Goldsmith says. “The value depends on feed costs, component pricing and how the soybeans fit into the overall feeding strategy.”
As more feeding data comes in, high-oleic soybeans are likely to remain part of the conversation as farms look for ways to balance feed costs, milk components, and homegrown feed opportunities.
