Bt176 sheep feeding study - another case of scientific fraud? (13/3/2008)

Bt176 sheep feeding study -- another case of scientific fraud?
Press Notice from GM Free Cymru, 10th March 2008

An Italian feeding trial, in which some sheep were fed the controversial maize line Bt176 over a period of 3 years, appears to have been specifically designed and conducted in order to confirm the 'no health risk' hypothesis (1).

In 2002-2005 scientists at the University of Perugia, with funding from the Italian Ministry of Health, conducted a 'longitudinal' study involving 106 breeding ewes, of which one group was fed on a diet containing Bt176 maize. The full article has crucial information missing, and appears to be systematically biased. The following points emerged in a reading of the text:

1. The preamble states: 'There is a lack of long-term studies, performed on a high number of animals over several generations, aimed at evaluating the effects of genetically modified (GM) feeds on livestock species.' It is implied that this paper will address this issue, but it does nothing of the sort. Only one generation of ewes was fed on the GM maize, and their lambs were fed no GM at all. The actual size of the test group is not given anywhere in the paper.

2. The quantity of GM feed fed to the test group of ewes was very small, at 5.6% of their diet, except during lactation, when the proportion increased to 19.4%. Overall, the test group was fed 17 times more hay than GM maize.

3. The researchers found important differences in 4 out of 30 investigated blood parameters (ie. 13.33 percent of parameters). Some items were very close to statistical significance (e.g. ALT, P=0.053; Platelet, P=0.060; WBC, P=0.056) and yet these results were effectively disregarded or dismissed.

4. The histological differences picked up between the control group of ewes and the test (GM) group are said to be 'preliminary' -- we suspect because the scientists on this part of the project were not allowed to perform a detailed or extended study on the histological samples.

5. The PCR cited for Bt176 is not reliable, as it does not give the GM maize used, only the genes in plasmids. This is a common method used by the GM industry in the falsification of results (2).

6. It is also useful to recall the following: Bt 176 was one of the GM inserts analysed by both French and Belgian scientists. The company Syngenta claimed the transgene is crylAb. Comparison with the public database revealed that the transgene has only 65% homology with the native crylAb, but 94% homology with a synthetic crylAc (3).

7. Following brief references to 'cell nuclear modifications' and 'functional modifications' the authors of the paper fail to consider the implications or causes in any detail. In their abstract they say: 'No modifications of histological features of tissues were found; however, cytochemical analyses of ruminal epithelium by Ki67 staining provided evidence of proliferative activation of basal cells in all GM maize-fed ewes. Preliminary electron microscopy analyses of the liver and pancreas revealed smaller cell nuclei containing increased amounts of heterochromatin and perichromatin granules in GM maize-fed lambs.'

In its investigation of these results GM Free Cymru discovered that the original referees of this paper did express concerns about these physiological changes, and asked for them to be investigated and elucidated, but that the journal accepted the piece in any case for publication.

Speaking for GM Free Cymru, Dr Brian John said: 'We have been checking on this study from its early days, following the award of grant aid in the year 2000. In the year 2004, no doubt under pressure from Syngenta, and following the discovery of the cellular changes mentioned above, a decision was made to abandon the research and to withhold it from publication. This was a particularly sensitive time for Syngenta, following the revelations that cows that died in Hesse, Germany, had been fed on Bt176 maize (4). Later, the decision was taken to write up the research results and to submit them for publication, possibly because Syngenta had already decided to withdraw Bt176 from the market (5).'

'But from the beginning this study -- like most other feeding studies -- was designed to prove the nutritional equivalence of the GM and non-GM maize lines, and to demonstrate that the 'health' and 'performance' of animals was not negatively affected by the consumption of GM feed. It has all the signs of a paper carefully manufactured for the promotion of a particular conclusion acceptable to Syngenta. The results of the study were effectively predetermined when the GM component in the feed was made absurdly small. Further, just one small group of breeding ewes was fed on the test diet when the opportunity could have been taken to study three generations. And a request for more detailed studies was refused when evidence of proliferative activation of basal cells was discovered.

'This is a profoundly unsatisfactory study, biased from the beginning towards a 'no harm' conclusion, and we see it as yet another example of the insiduous and sinister influence of the GM corporations on the research work of honest scientists in academic institutions.'

'The only consolation which we can draw from this piece of work is that the evidence of damage to the pancreas, liver and ruminalepithelium of the ewes fed on GM maize in this study may have helped to convince Syngenta that Bt176 was an unstable and fundamentally dangerous variety and to speed its demise.'


Contact: Brian John
GM Free Cymru
Tel 01239-820470


(1) Trabalza-Marinucci, M., Brandi, G., Rondini, C., Avellini, L., Giammarini, C., Costarelli, S., Acuti, G., Orlandi, C., Filippini, G., Chiaradia, E., Malatesta, M., Crotti, S., Antonini, C., Amagliani, G., Manuali, E., Mastrogiacomo, A., Moscati, L., Haouet, M., Gaiti, A., Magnani, M. 2008. A Three-Year Longitudinal Study on the Effects of a Diet Containing Genetically Modified Bt176 Maize on the Health Status and Performance of Sheep. Livestock Science. 113:178-190.

(2) Monsanto used a similar technique in its submissions in Japan relating to RR soy: