Research Highlights

Research Highlights
Creating Value-Added Pork with High Oleic Soybean Oil in Swine Diets

Finishing pigs such as these were fed diets containing high oleic soybean oil two to four weeks before slaughter to supplement with monosaturated fat. Photo: Crystal Levesque

By Carol Brown

Producers and nutritionists have been advancing pork over the last few decades to become another choice for a lean cut of meat. By 2006, pork contained 27 percent less saturated fat than it did 15 years prior, according to the Pork Checkoff.

With the growing public interest in monounsaturated fatty acids, the pork industry is looking at how it can enhance meat quality. Crystal Levesque, South Dakota State University animal science associate professor, is leading a project to see if swine diets that include high oleic soybean oil can improve the meat profile of pork. Supported by the South Dakota Soybean Checkoff, Levesque and her team of research associates are comparing finishing pigs fed with either animal fat or high oleic soybean oil.

“There is a benefit to humans for having high oleic soybean oil in their diet. Ruminants can convert unsaturated fat in their diets into saturated fat,” Levesque explains. “Pigs can’t do that. Whatever fat they consume in their diet, that’s the type of fat we find in their bodies, which then transfers to us when we eat the meat.”

Levesque and her research team divided nearly 300 finishing pigs into two groups. Half were fed a mix of corn, soybean meal and choice white grease, which is a specific USDA grade of mostly pork fat. They fed the other half the same feed but with high oleic soybean oil instead of the choice white grease. The pigs were on the diet for either two or four weeks prior to going to market. They also had an additional control group of pigs that had neither type of fat in their diets.

“We found the pigs that were fed the high oleic soybean oil had a higher average daily gain than either of the other groups,” she says. “The pigs with high oleic soybean oil had slightly better feed efficiency, although there wasn’t a lot of difference in feed intake. The most responses in feed efficiency were in the third and fourth weeks for both the groups being fed a fat supplement.”

The economics of adding a fatty acid supplement to swine feed becomes somewhat complicated, especially when fluctuating grain markets, meat packer costs and pork commodities all come into play.

“When producers include fat in a finishing pig diet, it adds a cost to that diet,” Levesque remarks. “But, typically for every 1% inclusion of fat, pigs are about 2% more efficient with their feed. When we compare choice white grease to high oleic soybean oil, using the grease is cheaper. But if producers can get a benefit of growth improvement, there is value in paying for a more expensive diet. We wanted to see the pigs’ performance differences in those final weeks before going to market.”

After slaughter, the team compared fatty acid profiles in the belly fat and the loin. 

Students in the meat science program at North Dakota State University prepare pork loin for the consumer sensory panel to compare loins that were fed high oleic soybean oil, choice white grease, or neither fat source. The research was conducted through a South Dakota State University project with nearly 300 finishing pigs. Photo: Crystal Levesque

“Both groups of pigs that were fed a fat source had heavier bellies, or greater belly yield,” Levesque says. “That’s important, as bacon comes from the pork belly and bacon is one of the highest priced cuts of meat on the pig.”

Levesque also found the bellies of pigs fed high oleic soybean oil had high concentrations of oleic fatty acid, which was expected, and the concentrations were slightly higher than the pig bellies with choice white grease. Belly weights were nearly the same between the two groups. The loin profiles were similar between the two groups, but the loins in the high oleic soybean oil group had slightly higher color and firmness scores.

The team also conducted a sensory evaluation with a consumer panel, comparing the loins with the two fat sources as well as the control with no fat supplementation. Levesque’s team partnered with the meat science department at North Dakota State University for these tests. 

The two panels totaling 96 participants tasted samples of grilled pork loin from each treatment. They evaluated the samples for juiciness, tenderness and flavor. The consumer panel results are in the evaluation process.

“Pork meat is healthy in general, and if there is a way to get this better source of fat into something we’re already consuming, there’s an increased benefit,” says Levesque. “And if the pork industry can promote this value-added meat to our export markets that put more emphasis on this aspect, that in turn helps the soybean market.”

Published: Jan 8, 2024

The materials on SRIN were funded with checkoff dollars from United Soybean Board and the North Central Soybean Research Program. To find checkoff funded research related to this research highlight or to see other checkoff research projects, please visit the National Soybean Checkoff Research Database.