Genetically Enhanced Soybeans

Soybeans with reduced oligosaccharides and phytate phosphorus have been developed. Feeding studies with growing pigs and broiler chicks were conducted to assess low phytate, low oligosaccharide soybean meal (LP-SBM) and a near-isogenenic, normal soybean meal (N-SBM). The total phytate, non-phytate phosphorus and the total oligosaccharides in the LP-SBM and N-SBM were 0.77, 0.22, 0.55, 1.08 and 0.70, 0.48, 0.22, 6.28%, respectively. Slope-ratio analysis of bone traits indicated that considerably more of the phosphorus in LP-SBM was bioavailable to pigs (49 to 19%) and chicks (58 to 28%) than phosphorus in N-SBM. Additional studies compared diets with normal and low-phytate corn supplemented with N-SBM and LP-SBM . Optimal growth and bone mineralization were achieved with less dietary supplemental inorganic phosphorus with the LP-SBM and LP-corn diets compared to the N-SBM and N-corn diets that were fed. Pigs and chicks fed the LP-SBM and LP-corn diet excreted 50% less phosphorus than those fed conventional soybean meal and corn diets. These studies support the nutritional and environmental advantages of soybeans genetically modified to contain reduced levels of oligosaccharides and phytate phosphorus.

Cromwell, G.L., E.G. Xavier, L.W.O. Souza, S.L. Traylor, L.A. White, M.D. Lindermann, T.E. Sauber, H.L. Stilborn and D.W. Rice. Proceeding of the Soy 2000 8th Biennial Conference of the Cellular and Molecular Biology of the Soybean, held August 13-16, 2000 in Lexington, Kentucky.