[img_assist|nid=254|title=|desc=|link=none|align=left|width=100|height=43]"Summarising the study, the maize with the stacked event NK603 x MON810 affected
the reproduction of mice in the RACB trial." - that is the conclusion of a study conducted by Austrian scientiest, commissioned by the Austrian ministries for agircultere and environement and for health.
On more then 100 pages the authors give details of their long-term study over 4 generations of mice. In addition to reproduction rates and organ weights, the authors also looked at the way genes were expressed differently depending on GM and non-GM diet: "In total 439 genes were found to be expressed differentially." (For details of the results and discussion see the full report.)
The reaction from Monsanto on a press release on the study was predictable: First of all Monsanto wanted to see the full study before commenting. Fair enough. But secondly, Monsanto already criticized the study as not peer-reviewed. True - but then again: Monsanto's own studies that were used as basis for the approval of their GM crops are not peer-reviewed either. So would Monsanto consider their own studies as not valid either.
The study of the Austrian scientists also draw attention to the criteria the EFSA applies for its risk assessment of GM crops. In October 2005, EFSA gave a positive opinion for NK603xMON810 for use as food & feed.

NK603xMON810 is a hybrid from a herbicide-tolerant and a Bt-toxin producing GM maize. GM hybrids are generally assessed by EFSA simply as two separate entities, leaving possible synergistic effects out.
Velimirov A., Binter C. & Zentek J. (2008): Biological effects of transgenic maize NK603 x MON810 fed in long term reproduction studies in mice. Bundesministerium für Gesundheit, Familie und Jugend, Forschungsbericht der Sektion IV, Band 3/2008. (German summary)