Soybean meal remains a cornerstone protein source in swine diets, but researchers at Kansas State University are exploring how variability in soybean meal composition—particularly with the reintroduction of byproducts—could impact swine nutrition.
Katelyn Gaffield, assistant research professor in swine nutrition at K-State, is leading an innovative research effort to better understand the nutritional impact of soybean byproducts such as soybean gums and soapstocks—materials derived from oil refinery processes—being added back into meal formulations.
“This began during my doctoral research,” Gaffield noted. “We sampled from 15 different soybean processing plants with help from the United Soybean Board to examine the variation in these byproducts.”
The findings revealed significant differences in color, viscosity, fat content, and moisture levels, with fat levels increasing when these byproducts were reintroduced into the soybean meal. Despite this, there was no significant change in crude protein levels—a key consideration for producers concerned about diet quality.
“Plants generally reintroduce these byproducts up to a limit—often until crude protein levels approach the minimum threshold,” said Gaffield.
In a recent nursery pig study, Gaffield’s team tested soybean meal containing added gums and soapstocks. The results showed no notable difference in pig growth performance, suggesting producers may not need to worry about variation in byproduct content across soybean meal sources.
“This is a positive result for producers,” Gaffield said. “It means there may be more flexibility in sourcing soybean meal without sacrificing performance—even when byproducts are present.”
As feed ingredient prices fluctuate and soybean meal sourcing becomes increasingly nuanced, this research brings reassurance and could influence how swine producers evaluate feed inputs moving forward.
