Safety Assessment Of Genetically Modified Rough Rice In Broiler Diets

Three experiments were conducted to evaluate the safety of genetically modified rough rice with Bt(Bacillus thuringiensis) gene used in broiler diets. The nutrient composition of the rice and its effects on performance, muscle composition, apparent nutrient digestibility of diets, serum biochemical parameters and intestinal microflora were analyzed to determine statistical differences between diets.Ecperiment 1 In this experiment, the nutrient content (conventional nutritive, amino acids, minerals and apparent metabolizable energy) of a genetically modified rough rice Bt110 (Bt rice) and its nontransgenic control Xiushui110(Xs rice) were analyzed and compared to determine whether it can meet the requirement of"substantial equivalence"in nutrient composition.The results showed that, although most of their nutrient composition were similar, the content of crude protein(6.69%Vs.9.66%), Fe(8.0 mg/kg Vs.25.1 mg/kg) and 17 kinds of amino acids of Bt rice were apparently lower than Xs rice. Therefore, we draw a conclusion that the genetically modified rough rice used in this study was not"substantially equivalent"to its nontransgenic control.Experiment 2 A 35-d feeding study was conducted to evaluate the effects of Bt rice on performance and muscle composition of broiler chickens. 320 8-d-old AA broilers were weighed one by one and allocated to 2 treatments, each with 8 pens of males(10 broilers/pen) and 8 pens of females(10 broilers/pen), fed diet prepared from Bt rice(Bt group) or Xs rice(Xs group) separately. In order to evaluate the effects of Bt rice on apparent nutrient digestibility of diets, 96 8-d-old AA broilers were weighed one by one and allocated to 2 groups with 8 replications of 6 birds, one group were fed diet prepared with Bt rice(Bt group) and the other were fed diet prepared with Xs rice(Xs group). The results showed that, performance of Bt group were better than Xs group. Compared with Xs group, male birds of Bt group grew extremely better(P<0.01) in the phases of 22～42d and 8~42d. In these two phases, female birds of Bt group also grew better, there are extremely difference(P<0.01) in ADG and ADFI between the two groups, but FCR was not different (P>0.05).The content of DM, CP, EE in breast and leg muscle were similar(P>0.05) between the two treatments. Except for a...