Researchers at the University of Illinois conducted an experiment to compare chemical composition and standardized ileal digestibility (SID) of amino acids in soybean meal (SBM) from five countries when fed to growing pigs. Five sources of SBM from China, Argentina, Brazil, and the U.S., and four sources from India were included in diets where SBM was the sole source of amino acids. An N-free diet was also used. Twenty-five barrows weighting about 30 kg were fitted with a T-cannula in the distal ileum and allotted to a 25 × 8 Youden square design with 25 diets and 8 periods.

Results indicate that the concentration of crude protein was greater (P ‹ 0.05) in SBM from Brazil and India (49.3 and 49.5%) than in SBM from China, Argentina, or the U.S. (45.1, 46.7, and 47.3%), but SBM from the U.S. contained more (P ‹ 0.05) indispensable amino acids compared to SBM from China or Argentina. Indian SBM contained more (P ‹ 0.05) trypsin inhibitor units than SBM from other countries. A greater (P ‹ 0.05) SID of most amino acids was observed in SBM from the U.S. compared with SBM from Brazil, Argentina, and India. There was less (P ‹ 0.05) variability in SID values for amino acids among sources of SBM from the U.S. or Brazil compared to sources from Argentina, China, or India. The researchers concluded that the SID of amino acids in SBM is dependent on the country where the SBM is produced.