At the 2026 ASAS Midwest Section meeting, Dr. Robert Easter, Professor Emeritus of swine nutrition and President Emeritus, University of Illinois, spoke at the U.S. Soy℠-sponsored Swine Application Symposium, offering a historical perspective on one of the most important developments in modern pig production: the corn-soybean meal diet.

By the late 1800s and early 1900s, soybeans had made their way into the Midwest, where farmers began experimenting with them primarily as forage crops. Early feeding practices often involved grazing pigs directly on soybean plants, supplementing more traditional feed ingredients like corn.

One of the earliest breakthroughs came from researchers Thomas Burr Osborne and Lafayette B. Mendel, who evaluated protein quality using nitrogen retention studies in the 1910s at the Connecticut Agricultural Experimental Station. Their work demonstrated that soy protein was highly effective in supporting growth – an important step toward recognizing its value in animal diets.

Once researchers understood that pigs require vitamin B12, and that it was naturally supplied in animal proteins but absent in plant-based diets – the solution became clear. Supplementing B12 allowed plant-based diets to match the performance of traditional rations. This discovery removed a critical barrier to the adoption of corn-soy diets and marked a turning point in swine nutrition.

By 1953, corn-soy diets were officially recommended, and adoption spread quickly.

Watch the interview below or read more here. Or watch Dr. Easter’s full presentation here.