Feed from GM-plants in poultry nutrition and future challenges
In the future there will be a strong competition for arable land between food/feed, fuel, fibre and further industrial materials as well areas for settlements and natural conservation. Therefore high yielding plants with low external inputs should be the main aim of plant breeding. Apart from traditional plant breeding plant biotechnology seems to have a certain potential to contribute to this objective. Presently, we are in an initial phase of this breeding technology. The cultivation of genetically modified plants (GMP) increased from 1.7 (1996) to about 148 million ha (2010) (about 10% of arable land all over the world). Most modified cultures are soybean, maize, cotton and rapeseed, mainly with increased tolerance against herbicides and insecticides or higher resistance against insects. Safety and nutritional assessment of food/feed from GMP is urgently necessary. There exist strong guidelines for these assessments in many countries. The results of the nutritional studies can be summarized as follow. Nutritional assessment starts with compositional analysis followed by digestion and feeding studies, fates of transgenic DNA and newly expressed proteins. Up to now most studies were done with GM-crops of the 1st generation (plants with input traits; without substantial changes in composition). No unintended effects in composition or contamination (except lower concentration of mycotoxins) and nutritional assessment of feeds from GM-crops of the 1st generation were registered in about 150 scientific studies with food producing animals. Most of the studies were done with rapidly grown chicks. Transgenic DNA and newly expressed proteins did not show other properties as plant DNA or endogenous plant proteins during feed treatment or in the animals. Other experimental designs for nutritional and safety assessments are recommended for GMcrops of the 2nd generation (plants with output traits, with substantial changes in composition).