Suitability of Soybean Meal from Insect-Resistant Soybeans for Broiler Chickens María A. Ortega, † Adam J. Davis, ‡ H. Roger Boerma, † and Wayne A. Parrott* ,† † Institute of Plant Breeding, Genetics and Genomics, University of Georgia, 111 Riverbend Road, Athens, Georgia 30602, United States ‡ Department of Poultry Science, University of Georgia, 342 Poultry Science Building, Athens, Georgia 30602, United States ABSTRACT: Benning M and Benning MGH are near-isogenic lines (NILs) of the soybean cultivar Benning, which contain insect- resistance quantitative trait loci (QTLs) from the soybean accession PI 229358. Benning M contains QTL-M, which confers antibiosis and antixenosis. In addition to QTL-M, Benning MGH contains QTL-G, which confers antibiosis, and QTL-H, which confers antixenosis. Soybean meal was produced from Benning and the NILs. Nutritional composition, digestible amino acid content, and nitrogen-corrected true metabolizable energy (TME N ) were equivalent among soybean meals. A 21-day broiler feeding trial was carried out to determine if the QTLs affect soybean meal quality. Weight gain and feed-to-gain ratio were evaluated. No biologically significant differences were detected for broilers fed Benning, Benning M , and Benning MGH . This demonstrates that soybean meal produced from the insect-resistant NILs is equivalent to soybean meal produced from their non-insect-resistant parent cultivar for broiler weight gain. KEYWORDS: soybean, insect-resistance QTLs, near-isogenic lines, soybean meal, broiler performance ■ INTRODUCTION Broiler feeding trials have become a standard test to assess the nutritional suitability of genetically modified crops. 1 Some jurisdictions even consider them as providing a screen to guard against the unintentional presence of harmful side effects from the modification. 2,3 In contrast, similar traits obtained via conventional breeding are seldom tested for safety. 4 Insect resistance in soybean [Glycine max (L.) Merr.] is an example of a trait that can be obtained either transgenically 5 or conventionally. 6 Soybean seeds are a major protein source for animal feed. 7 Worldwide, 11% of the crop is lost to animal pests, including insects, 8 of which leaf-chewing insects are economically important in the southern United States. 9 Although soybeans can withstand moderate leaf damage, high levels of defoliation greatly reduce seed yield and quality. 10 Therefore, plant re- sistance to leaf-chewing insects is essential for preventive pest management; it promotes efficient use of insecticides, diminish- ing crop production, and environmental concerns. In soybeans, nontransgenic resistance to a broad range of leaf-chewing insects 11-26 is found in the Japanese soybean landrace ‘Sodendaizu’ PI 229358, 27 from which it has been bred into several modern cultivars. PI 229358’s resistance is conferred via antibiosis and anti- xenosis. 28,29 In antibiosis, the plant has detrimental effects on insect growth, development, and/or reproduction. 30 In anti- xenosis, the plant affects insect behavior by discouraging oviposition, colonization, and/or feeding. 30,31 Three quantitative trait loci (QTLs) confer PI 229358’s resistance. QTL-M, on chromosome 7, provides both antibiosis and antixenosis. QTL-H, on chromosome 12, conditions antixenosis, whereas QTL-G, on chromosome 18, conditions antibiosis. 28,29 QTL-M is required for the expression of QTL-H and QTL-G. 32 The chemical nature of the resistance conferred by these QTLs remains largely unknown. Inasmuch as the products from PI 229358 QTLs are detrimental to insect growth and behavior, there is a concern that meal derived from such insect-resistant soybean seed could also have detrimental effects on animals when used for feed. Although rare, a few past efforts to develop disease-resistant cultivars through conventional breeding led to unacceptable levels of undesirable metabolites. The potato cultivar Lenape accumulated high levels of glycoalkaloids, 33 and disease- resistant celery containing high levels of furanocoumarins was associated with dermatitis among grocery store personnel. 34,35 Therefore, it is prudent to ensure that soybean meal produced from plants carrying QTL-M, QTL-G, and QTL-H is as safe and wholesome as soybean meal produced from seed without these QTLs. To determine if the addition of insect-resistance QTLs has negative effects on the feed quality of soybean meal, soybean meals were produced from soybean NILs containing the QTLs described earlier. Digestible amino acid content and nitrogen- corrected true metabolizable energy (TME N ) were measured for each soybean meal, and diets containing each soybean meal were evaluated in a 21-day broiler feeding trial. ■ MATERIALS AND METHODS Soybean Meal Production. Benning 36 and its insect-resistant NILs 6 were used in this study. Benning M contains QTL-M, whereas Benning MGH contains QTL-M, QTL-G, and QTL-H. Figure 1 shows Benning, Benning M , and Benning MGH plants in the field, exposed to Received: December 23, 2015 Revised: February 23, 2016 Accepted: March 7, 2016 Article pubs.acs.org/JAFC © XXXX American Chemical Society A DOI: 10.1021/acs.jafc.5b05992 J. Agric. Food Chem. XXXX, XXX, XXX-XXX