Comparison of broiler performance and carcass yields when fed diets containing genetically modified canola meal from event DP-Ø73496-4, near-isogenic canola meal, or commercial canola meals

Genetically modified (GM) canola (Brassica napus L.) line containing event DP-Ø73496-4 (hereafter referred to as 73496 canola) was produced by the insertion of the glyphosate acetyltransferase (gat4621) gene derived from Bacillus licheniformis. Expression of the GAT4621 protein present in 73496 canola plants confers in planta tolerance to the herbicidal active ingredient glyphosate. The objective of this study was to compare the nutritional performance of broiler chickens fed canola meal from 73496 canola seed with that of broiler chickens fed non-GM canola meal in a 42-d feeding trial. Diets were prepared using meal processed from seed from unsprayed 73496 plants or from plants sprayed with an in-field application of glyphosate herbicide [73496(S)]. For comparison, additional diets were produced with canola meal obtained from the non-GM near-isogenic control or non-GM commercial reference DuPont Pioneer brand varieties 42H72, 42H73, 46A65, and 44A89. Diets were fed to Ross 708 broilers (n = 120/group, 50% male and 50% female) in 3 phases: starter and grower phases containing 10 or 20% canola meal, respectively, and a finisher phase with a common corn-soybean meal diet without any canola meal. No statistically significant differences were observed in growth performance measures or organ and carcass yields between broilers consuming diets produced with canola meal from unsprayed or sprayed 73496 seed and those consuming diets produced with canola meal from control seed. Additionally, all performance, organ, and carcass measures from control, 73496, and 73496(S) canola treatment groups were within tolerance intervals constructed using data from the reference canola groups. It was concluded from these results that meal processed from 73496 canola seed (unsprayed plants or plants sprayed with glyphosate) was nutritionally equivalent to meal processed from non-GM near-isogenic control canola seed.