Two experiments were conducted to determine the digestibility of energy and nutrients and the concentration of DE, ME, and NE in fermented soybean meal (FSBM), conventional soybean meal (SBM), and fish meal fed to weanling pigs. In the first experiment, barrows weighing about 22kg were fed a corn-based diet or a diet consisting of corn plus the test ingredient (FSBM, SBM-CV, and fish meal). Results indicated that the apparent total tract digestibility (ATTD) of GE in corn, FSBM, and SBM was 88.6, 88.2, and 90.3%, respectively, but the ATTD of GE in fish meal (84.0%) was less (P < 0.01) than in the other ingredients. The concentrations of DE, ME, and NE in SBM were 4,553, 4,137, and 2,972 kcal/kg DM. These values were greater (P < 0.01) than the DE, ME, and NE in FSBM, corn or fish meal based diets. The calculated biological value of the protein in fish meal (75.4%) was greater (P < 0.05) than in corn (34.8%) and FSBM (62.8%), and the biological value of protein in SBM (67.1%) was greater (P < 0.05) than in corn, but not different from FSBM and fish meal.

In the second experiment, eight barrows weighing about 10.4 kg were equipped with a T-cannula in the distal ileum and randomly allotted to a replicated 4 × 4 Latin square design experiment with four diets and four feeding periods. Three diets containing FSBM, SBM, or fish meal as the sole source of amino acids and an N-free diet were formulated. The standardized ileal digestibility (SID) of all indispensable amino acids except lysine, threonine, and tryptophan were greater (P < 0.01) in FSBM than in fish meal. The SID of methionine and valine was also greater (P < 0.05) in FSBM than in SBM, but for the remaining indispensable amino acids, no difference between FSBM and SBM was observed. The researchers concluded that DE, ME, and NE are greater in SBM compared to FSBM and fish meal and the SID of most amino acids are not different between FSBM and SBM.