Raw soybeans contain antinutritional factors such as trypsin inhibitors (TI) and lectins.  The production of soybean meal involves a heating step, which reduces these anti-nutritional factors. However, conventional soybean meal contains compounds which can cause digestive disturbances in weanling pigs. Soybean meal is therefore limited in pig starter diets. Other protein sources, such as fish meal, casein, and soy protein isolate, are used for young pigs.

Two new soybean products were recently introduced to the U.S. feed market.  Fermented soybean meal (FSBM) and enzyme-treated soybean meal (ESBM) are believed to have a lower concentration of antinutritional factors and a higher concentration of crude protein and amino acids than conventional soybean meal.  They are also believed to be better tolerated by young pigs. However, not much is known about the digestibility of the protein in these two products.

This experiment was conducted to compare the digestibility of amino acids in weanling pigs of FSBM, ESBM, conventional de-hulled soybean meal, fish meal, casein, and soy protein isolate.