Studies on feeds from genetically modified plants (GMP) – Contributions to nutritional and safety assessment

Since 1997, 18 studies with feeds from genetically modified plants (GMP) in the nutrition of dairy cows, growing bulls, growing and finishing pigs, laying hens, chicken for finishing as well as growing and laying quails were conducted at the Federal Agricultural Research Centre (FAL) in Braunschweig (Germany).The majority of the experiments (16) were undertaken with GMP of the so-called first generation (plants with input traits and without substantial changes in composition) such as Bt-maize, Pat-maize, Pat-sugar beet, Gt-soybean, Gt-potatoes and Bt-potatoes. Two studies were carried out with GMP of the second generation (plants with output traits or with substantial changes in their chemical composition) such as an altered fatty acids profile in rapeseed or inulin potatoes. In all experiments, feeds from GMP were compared with their isogenic counterparts.The iso- and transgenic feeds were analysed for their composition (proximates, fibre fraction, amino acids, fatty acid pattern, minerals) and undesirable substances (e.g., mycotoxins). Animal studies were carried out for nutritional and safety assessment such as digestibility, feed intake, health and performance of target animal species and quality of food of animal origin. Reproduction was studied in a 10-generation experiment with quails and a 4-generation experiment with laying hens. Duration of experiments and number of animals were limited in some cases due to small amounts of GM-feed available for experimentation.Attention was drawn to the fate of DNA during feed processing (silage making, oil extraction), in the digestive tract of animals (slaughtering of animals 0, 4, 8, 12 and 24 h after feeding) and in the animal body (samples from several organs and tissues).In agreement with more than 100 animal studies available to date, results show no significant differences in the nutritional value of feeds from GMP of the first generation in comparison with non-GMP varieties. To date, no fragments of recombinant DNA have been found in any organ or tissue sample from animals fed GMP. The lower content of mycotoxins in Bt-maize and side effects in GMP of the second generation are of safety concern.The results indicate that routine feeding studies with target animal species add little to nutritional assessment of feed from GMP of the first generation, but they are of public interest and important for safety assessment. These studies will play a more important role in nutritional and safety assessment of feeds from GMP with output traits. Proposals for such studies were made on the basis of previous experiments.