World Dairy Expo: High oleic soybeans gain ground in dairy rations

19 November 2025

4 minute read

By: Sarah Mikesell

North America

Stacy Nichols, dairy technical sales manager at Vita Plus and member of the dairy advisory board at U.S. Soy, spoke to The Dairy Site’s Sarah Mikesell at World Dairy Expo in Madison, Wisconsin, USA about the value of high oleic soybeans. 

How are producers using high oleic soybeans in dairy cow diets today? 

We're starting to see a lot of adoption of high oleic soybeans in the industry. Most dairy producers would be feeding 3 to 7 lbs. per head per day in their lactating ration, although we've seen producers feed a lot more than that. The benefit of using high oleic soybeans is a reduction in purchased feed cost, and it's mainly on the supplemental fat side. 

What benefits are producers seeing because of feeding high oleic soybeans? 

I've been in the industry 30 years, and one of the challenges we have in formulating lactating cow rations for the modern dairy cow is I don't think we put enough fat in her rations. High oleic soybeans have given us an opportunity to do that but offset the price of dry supplemental fats. 

How can producers get the most out of high oleic soybeans? 

Today, we've been substituting by removing a lot of supplemental fat. I'm not sure that's necessarily the best approach. We might need to leave a little bit of fat in and that research is coming. Also, producers are getting the benefit from the protein of high oleic soybeans. Soy protein is a very good protein for lactating dairy cattle, and we're able to replace some of those purchased protein costs with high oleic soybeans. 

What should producers look for in a well-roasted high oleic soybean? 

The first thing you want to look for is — is it actually roasted? This is a challenge that we're having in the industry today. We have forgotten how to roast soybeans but we're getting better at doing it. You want it to be the color of soybean meal or darker because that's an indication that it's well-roasted. Does it need to be roasted to the level that some of our bypass soy proteins have been? I'm not sure we have to go there, especially if we're feeding high levels, but we need to make sure they are well-roasted, and we have gotten rid of anti-nutritional factors. We've improved the bypass protein portion of that high oleic soybean through the roasting. 

Why is a well-roasted soybean important? 

There are anti-nutritional factors in raw soybeans, which we've always thought were related to problems in calf nutrition and monogastric nutrition. I think at really high levels of feeding, we've seen that in some of the research that it's a problem in lactating cows. I don't think we want to feed high oleic soybeans raw. 

Getting them roasted protects the protein from degradation by the rumen microbes, and by doing that you've taken a good quality protein and been able to deliver that to the small intestine of the cow. She is then able to absorb those amino acids of that good quality protein that helps her make more milk protein and more milk overall. That's the reason we're looking for a well-roasted soybean. The more we roast them ,the more bypass protein we have and that provides more good quality amino acids that we're able to deliver to the cow. So, we want them well-roasted. 

There are things that a producer can look for through lab analysis. Using the Protein Dispersibility Index ( PDI), we want beans to be somewhere between 9 to 11, if we're replacing our bypass soy sources that are in the ration and some of the other bypass proteins we feed. If we're going to feed really high levels of them, we could back off and have a PDI of 11 to 14. That would still provide good quality protein, and we've also gotten past those anti nutritional factors. 

The other thing that we're looking for in the soybeans is we want them at a particle size where the cow isn't going to pass them all the way through without digestion. We don't want it so fine that we're impacting rumen fermentation, and we're losing the bypass protein that we've heated the beans for. 

Micron size of somewhere between 600 and 850 microns is a good place to be and you can smell a good, quality roasted soybean.

How do high oleic soybeans work differently in the cow versus the non-high oleic or conventional soybeans? 

Conventional soybeans are high in linoleic acid. High oleic soybeans are about 70 to 75% oleic acid. Conventional soybeans are about 55% linoleic acid, and that's the big difference. 

We know based on 25+ year old research that linoleic acid is the primary factor in milk fat depression. When we remove the linoleic acid and we have more oleic acid, oleic acid doesn't have as much of an impact on milk fat depression. 

We can feed a lot of high oleic soybeans and feed the cow a lot of fat that we haven't been able to either because of cost or we had the problem— if we tried to feed a lot of fat, we caused milk fat depression especially if we were feeding it from vegetable oil sources, corn distillers, conventional soybeans and those kind of products.

When we're able to feed with the high oleic soybean, the oleic acid isn't as detrimental to milk fat production. What we're seeing from the levels of fat we can get into these cows is we're actually gaining more milk fat production because she's got more fat in the diet that she can put into milk fat.