Transgenic Soybean Feeding Studies

A genetically modified soybean (305423) that was produced by insertion of the gm-fad2-1 gene fragment and gm-hra genes into the germ line of soybean seeds. Expression of gm-fad2-1 results in greater concentrations of oleic acid (18:1) by suppressing expression of the endogenous FAD2-1 gene, which encodes an n-6 fatty acid desaturase enzyme that catalyzes desaturation of 18:1 to linoleic acid (18:2). The gm-hra gene results in protein enzyme that is used as a selectable marker during transformation. A 42-d feeding trial was conducted with broiler chickens to compare the nutritional performance of these transgenic soybeans with nontransgenic soybeans. Diets were prepared using processed fractions (meal, hulls, and oil) from transgenic soybean plants. For comparison, additional diets were produced with soybean fractions obtained from a nontransgenic near-isoline (control) and nontransgenic commercial Pioneer brand varieties. No statistically significant differences were observed in growth performance (body weight, mortality, feed efficiency), organ yield (liver and kidney), or carcass yield variables between broilers consuming diets prepared with isolated fractions from transgenic or near-isoline control soybean diets. The researchers concluded that based on the results from this study, transgenic (305423) soybeans were nutritionally equivalent to non-transgenic control soybeans with a comparable genetic background.

McNaughton, J., and co-workers. 2008. Comparison of Broiler Performance When Fed Diets Containing Event DP-3O5423-1, Nontransgenic Near-Isoline Control, or Commercial Reference Soybean Meal, Hulls, and Oil. Poultry Sci. (87): 2549-2561).