Safety assessment and feeding value for pigs, poultry and ruminant animals of pest protected (Bt) plants and herbicide tolerant (glyphosate, glufosinate)plants: interpretation of experimental results observed worldwide on GM plants

Abstract

New varieties of plants resistant to pests and/or tolerant to specific herbicides such as maize, soybean, cotton, sugar beets, canola, have been recently developed by using genetic transformation (GT). These plants contain detectable specific active recombinant DNA (rDNA) and their derived protein. Since they have not been selected for a modification of their chemical composition, they can be considered as substantially equivalent to their parents or to commercial varieties for their content in nutrients and anti-nutritional factors. However, insect protected maize is less contaminated by mycotoxins than its parental counterpart conferring a higher degree of safety to animal feeds. The new feeds, grain and derivatives, and whole plants have been intensively tested in vivo up to 216 days for their safety and their nutritional equivalence for monogastric farm animals (pig, poultry) and ruminants (dairy cows, steers, lambs). The present article is based on the interpretation and the summary of the scientific results published in original reviewed journals either as full papers (33) or as abstracts (33) available through September 2003. For the duration of the experiments adapted to the species, feed intake, weight gain, milk yield and nutritional equivalence expressed as feed conversion and/or digestibility of nutrients have never been affected by feeding animals diets containing GT plants. In addition, in all the experimental animals, the body and carcass composition, the composition of milk and animal tissues, as well as the sensory properties of meat are not modified by the use of feeds derived from GT plants. Furthermore, the health of animals, their physiological characteristics and the survival rate are also not affected.The presence of rDNA and derived proteins can be recognized and quantified in feeds in the case of glyphosate resistant soybean and canola and in the case of insect protected maize. However, rDNA has never been recovered either in milk, or in liver, spleen and muscles tissues of animals, or in rumen bacteria. On the basis of these data, it can be suggested that in vivo tests on high producing animals are necessary and sufficient to evaluate the safety and the nutritional value of new GT plants.Recentemente sono state sviluppate, mediante modificazione genetica, nuove varietà di piante (mais, soia, cotone, barbabietole da zucchero, canola) resistenti agli insetti e/o tolleranti a specifici erbicidi. Queste piante contengono specifici