RESEARCH at the University of Illinois is helping to determine the effect of growing conditions on the nutritional value of soybean meal.

According to Hans Stein, professor of animal sciences at the University of Illinois, "The digestibility of phosphorus is the same in soybean meal grown in various regions in the U.S."

Stein explained, "The chemical composition of soybean meal is somewhat dependent on the area in which soybeans are grown, but it was not known if there are differences in the concentration of phytate among soybeans grown in different areas."

He and Kelly Sotak-Peper, then a doctoral candidate, set out to determine whether any differences existed.

They sourced soybean meal from crushing plants in three different areas within the U.S.: (1) the northern growing area, comprising Michigan, Minnesota and South Dakota; (2) the eastern growing area, comprising Georgia, Illinois, Indiana and Ohio, and (3) the western growing area, comprising Iowa, Missouri and Nebraska.

They measured no statistically significant differences in concentrations of phosphorus or in the percentage of phosphorus bound to phytate among soybean meal samples from the different regions.

There were also no differences in apparent total tract digestibility (ATTD) or standardized total tract digestibility (STTD) among pigs fed soybean meal from the three growing areas.

When microbial phytase was added to swine diets to break down phytate, the ATTD and STTD of phosphorus in soybean meal from all growing areas increased by 24% and 22%, respectively.

"When you have ingredients that come from a wide variety of growing conditions, there's a risk that using book values for nutritional information will not give you accurate information for a given batch," Stein said. "What these data indicate is that an average value for ATTD and STTD of phosphorus may be used regardless of the area in which the soybeans are grown."

The research was supported by funding from the U.S. Department of Agriculture's National Institute of Food & Agriculture.

Soybean meal was donated by AG Processing Inc. in Omaha, Neb.; Archer Daniels Midland Co. in Decatur, Ill.; Bunge North America of St. Louis, Mo., and Cargill Inc. of Elk River, Minn.

The paper, "Effects of Production Area & Microbial Phytase on the Apparent & Standardized Total Tract Digestibility of Phosphorus in Soybean Meal Fed to Growing Pigs," was published in the June 2016 issue of the Journal of Animal Science. The full text can be found at http://bit.ly/sbmarea.

Volume:88 Issue:08