Performance of Herbicide-Resistant Soybean Meal

In another study, soybean lines (356043 and Optimum GAT) were genetically modified by inserting genes gat4601 and gm-hra genes. Which express glyphosate acetyltransferase 4601 and acetolactate synthase protein products, respectively. Expression of the glyphosate acetyltransferase 4601 protein confers tolerance in planta to the herbicidal active ingredient glyphosate, whereas expression of the acetolactate synthase protein confers tolerance to sulfonylurea and imidazolinone herbicides. The objective of this study was to compare the nutritional equivalence of this herbicide-resistant soybean line to isogenetic nontransgenic soybeans in a 42-d feeding trial in broiler chickens. Diets were prepared using processed fractions (meal, hulls, and oil) from untreated 356043 soybean plants or from soybean plants treated with a mixture of glyphosate, chlorimuron, and thifensulfuron (356043 + Gly/SU). For comparison, additional diets were produced with soybean fractions obtained from nontransgenic near-isoline and nontransgenic commercial Pioneer varieties. Diets were fed to broilers (n = 120/group, 50% male and 50% female) in three phases. Starter diets contained 30% soybean meal, grower diets 26% soybean meal, and finisher diets 21.5% soybean meal. No statistically significant differences were observed in mortality, growth performance variables, or carcass and organ yields between broilers consuming diets produced with herbicide-resistant soybean fractions and those consuming diets produced with near-isoline control soybean fractions. Based on the results from this study, the authors concluded this herbicide-resistant soybean was nutritionally equivalent to nontransgenic control soybean with a comparable genetic background.

McNaughton, J. and co-workers. 2007. Comparison of broiler performance when fed diets containing event DP-356043-5 (Optimum CAT), nontransgentic near-isoline control, or commercial reference soybean meal, hull, and oil. J. Poultry Sci. 86:2569-2581.