Comparative Nutritional Values of Soybean Ingredients

Two experiments were conducted comparing three sources of full fat soybeans (FFSB) to a soybean meal (SBM). The FFSB were produced from conventional (FFSB-CV), high-protein (FFSB-HP), and low oligosaccharide (FFSB-LO) varieties of soybeans that contained 37.6, 44.6, and 39.0% CP, respectively. The SBM was produced from a conventional variety of soybeans and contained 49.7% CP. The standardized ileal digestibility of amino acids in the four ingredients was measured using 10 barrows (10.1 ± 1.82 kg BW) that were equipped with a T-cannula in the distal ileum and allotted to a replicated 5 × 5 Latin square design with 5 periods and 5 diets per square. Three diets contained FFSB-CV, FFSB-HP, or FFSB-LO and one diet contained SBM as the sole source of amino acids. An N-free diet was used to determine basal ileal endogenous losses of amino acids. Each period lasted seven days and ileal digesta were collected on days six and seven of each period.

The standardized ileal digestibility for leucine, lysine and phenylalanine in FFSB-CV were greater (P <= 0.05) than in SBM, but no differences were observed in the standardized ileal digestibility of amino acids between FFSB-HP, FFSB-LO and SBM. The metabolizable energy in the soybean ingredients were measured using 40 barrows (18.5 ± 1.54 kg BW) that were placed in metabolism cages and randomly allotted to 5 diets. A corn-based diet and four diets containing corn and the soybean protein source were formulated. Urine and feces were collected over a 5-d period following a 7-d adaptation period. The metabolizable energy in each source of soybean ingredient was calculated using the difference procedure. The concentration of metabolizable energy in FFSB-CV, FFSB-HP, FFSB-LO, and in SBM was 4,990, 4,515, 4,769, and 3,970 kcal/kg DM, respectively. All values were different (P <= 0.05). These results indicate that FFSB-CV has a greater ideal digestibility of leucine, lysine and phenylalanine and a greater concentration of metabolizable energy than soybean meal when fed to weanling pigs. Ileal digestibility of full fat ingredients from high-protein, low-oligosaccharide soybeans were similar to soybean meal produced from conventional soybean varieties. Metabolizable energy values for these ingredients reflected both genetic and processing differences.

Baker, K.M. and co-workers. 2009. Amino acid digestibility and energy concentration in full fat soybeans from conventional, high protein, or low oligosaccharide varieties and in soybean meal fed to weanling pigs. Am. Dairy Sci. Assoc. and J. Animal Sci. Midwest Meeting, March 16-18, Abstract 181.